Student Assignments for HV-125-BWP_053389 Air brake driving simulator 95-HV-125-BWP_REVA © ConsuLab Educatech Inc, 2026. All rights reserved. 95-HV-125-BWP Table of Contents 400-6330 Zéphirin-Paquet St. Québec QC G2C 0M3 Canada consulab.com info@consulab.com Toll-free: +1 (800) 567-0791 USA: +1 (810) 222-4525 Canada: +1 (418) 688-9067 Fax: +1 (418) 843-3444 2 Table of Contents Introductory material 4 Description 4 Application 4 Educational Advantages 4 Orientation, preliminary inspection and system tests 5 Assignment 1 : Component locations, and color coding the HV-125-BWP 5 SA-2: Understanding how ABS and ATC systems work. 6 Questions for students 8 SA-3: Understanding the interaction between the governor and the compressor. 9 Questions for students 12 SA-4 - Test One — Pressure Inspection 15 SA-5 - Test Two — Leakage Inspection 16 SA-6 - Test Three — Chuff Tests 17 SA-7 - Test Four — Service Air Delivery Leakage 18 SA-8 - Test Five — Parking Brake Application 19 SA-9 - Test Six— Dual Circuit System Integrity 20 SA-10 - Checklist Six 21 Truck faults 22 SA-11 - HV-125-BWP Truck Pneumatic Fault F1 22 SA-12 - HV-125-BWP Truck Pneumatic Fault F2 23 SA-13 - HV-125-BWP Truck Pneumatic Fault F3 24 SA-14 - HV-125-BWP Truck Pneumatic Fault F4 25 SA-15 - HV-125-BWP Truck Pneumatic Fault F5 26 SA-16 - HV-125-BWP Truck Pneumatic Fault F6 27 SA-17 - HV-125-BWP Truck Electrical Fault F1 28 SA-18 - HV-125-BWP Truck Electrical Fault F2 29 SA-19 - HV-125-BWP Truck Electrical Fault F3 30 SA-20 - HV-125-BWP Truck Electrical Fault F4 31 SA-21 - HV-125-BWP Truck Electrical Fault F5 32 SA-22 - HV-125-BWP Truck Electrical Fault F6 33 SA-23 - HV-125-BWP Truck Electrical Fault F7 34 SA-24 - HV-125-BWP Truck Electrical Fault F8 35 SA-25 - HV-125-BWP Truck Electrical Fault F9 36 SA-26 - HV-125-BWP Truck Electrical Fault F10 37 95-HV-125-BWP Table of Contents 400-6330 Zéphirin-Paquet St. Québec QC G2C 0M3 Canada consulab.com info@consulab.com Toll-free: +1 (800) 567-0791 USA: +1 (810) 222-4525 Canada: +1 (418) 688-9067 Fax: +1 (418) 843-3444 3 © ConsuLab Educatech Inc, 2023. All rights reserved. No part of this work may be reproduced or transmitted in any form by any means, electronic, mechanical, including photocopying and recording, or by any information storage or retrieval system, without written permission from the publisher. Printed in Canada. The content of this manual is applicable to models 053389 and above. SA-27 - HV-125-BWP Truck Electrical Fault F11 38 SA-28 - HV-125-BWP Truck Electrical Fault F12 39 SA-29 - HV-125-BWP Truck Faulted Component #1 40 SA-30 - HV-125-BWP Truck Faulted Components #2 41 SA-31 - HV-125-BWP Truck Faulted Component #3 42 SA-32 - HV-125-BWP Truck Faulted Component #4 43 Trailer faults 44 SA-33 - HV-125-BWP Trailer Fault #1 44 SA-34 - HV-125-BWP Trailer Fault #2 45 SA-35 - HV-125-BWP Trailer Fault #3 46 SA-36 - HV-125-BWP Trailer Fault #4 47 SA-37 - HV-125-BWP Trailer Fault #5 48 SA-38 - HV-125-BWP Trailer Fault #6 49 SA-39 - HV-125-BWP Trailer Fault #7 50 SA-40 - HV-125-BWP Trailer Fault #8 51 Faulted wheel speed sensor 52 SA-41 - HV-125-BWP Wheel Speed Sensor 52 consulab.com info@consulab.com 4 95-HV-125-BWP Introductory material Introductory material Description The ConsuLab HV-125-BWP is a functional air brake trainer utilizing system components from Bendix® for the tractor and the trailer. The trainer is built to be used as a live driving simulator in front of a whole class as well as for learning the foundation air brake system, performing electrical and pneumatic diagnosis with the aid of fault boxes and with optional defective components. The trainer has been designed around the FMVSS121 standard and allows students to perform a driver pre-trip inspection. All components are D.O.T. approved. The HV-125 allows students to directly observe how the governor controls the air dryer purge, as well as the compressor loading and unloading phases (cut-in and cut-out). Application • The tractor system is a Bendix EC-80 Premium® system configured as 4S4M, this means 4 sensors and 4 modulator valves ; • The trailer system is a complete standalone system with Bendix TAB6®, ABS and rollover protection electronic sta- bility control ; • The Bendix AD-IS® air dryer that is used that includes a wet tank and safety valve for over pressure protection. This means that there are just two primary and secondary tanks for the main system ; • The primary and secondary tanks are equipped with drain valves. All tanks are equipped with safety valves set at the industry standard 150psi. • Starting with serial number _053389, the EC-60 Premium electronic control module has been updated and improved to the EC-80 Premium Educational Advantages • The learner can easily observe the various functions of the trainer and the interaction of the tractor and trailer ; • The air brake trainer fits through standard classroom doorways and is simple to set up ; • The wheel speeds for all wheels are shown on individual display screens throughout the trainer ; • The operator controls are positioned so that the operator does not obscure the students view of the trainers opera- tion ; • Many of the components are mounted on the board using thumbnuts so that the components may be removed without any tools ; • Optional faulted components are available that can be installed for diagnosis training. consulab.com info@consulab.com 5 95-HV-125-BWP Orientation, preliminary inspection and system tests Orientation, preliminary inspection and system tests Assignment 1 : Component locations, and color coding the HV-125-BWP Part 1 The location of individual components of the braking system is critical for the technician to learn as well as what they are each called. This assignment will allow individual students or teams of students to correctly identify all the compo- nents of the system. They will need to know this information to complete successive assignments. Use the included documentation from your instructor to locate and name the components on the system. Be sure to leave room for Part 2. Part 2 Knowing the functions of the airlines and where they are located will be important to your understanding of a modern air brake system. Color the individual circuits on the system diagram. TMC Recommended Practice #423 deals with which color applies to each circuit. Charging = Black Primary = Green Secondary = Orange Park (supply) = Red Parking (Control) = Yellow Accessories = Purple Carefully start coloring your drawing working from the top of this list to the bottom, until all circuits are colored. consulab.com info@consulab.com 6 95-HV-125-BWP Orientation, preliminary inspection and system tests SA-2 - Understanding how ABS and ATC systems work. Objective To help the student understand the role and basic operation of ABS and ATC systems in low-traction conditions, such as on an icy surface. Using the HV-125 trainer, the student will be able to observe how the vehicle reacts and adapts when one or more wheels are not rotating at the same speed as the others. He will be able to understand and explain why these systems intervene to improve the truck’s safety and stability. Scenario In winter conditions, a truck may lose traction when braking or accelerating on an icy road surface. A wheel may then lock up or lose traction, making the vehicle difficult to control. The ABS and ATC systems are designed to detect these situations and automatically correct the vehicle’s behavior. The HV-125 allows you to recreate these conditions in the classroom to observe the systems’ behavior in real time. Imagine a truck driving in winter: • When braking on ice, a wheel may lock up • When accelerating on ice, a drive wheel may spin These behaviors are dangerous and that’s why trucks are equipped with ABS and ATC. Theory The vehicle is equipped with wheel speed sensors that detect the movement of a tone ring mounted on each wheel assembly. The sensors generate an electrical signal whose frequency varies according to the speed of rotation of the wheels. The ABS control unit (EC-80) receives these signals from each sensor and continuously compares with one another. When all wheels are rotating at similar speed, the ABS system operates normally. If one wheel rotates faster or slower than the others, the control unit detects loss of traction. Depending on the situation, the EC-80 then sends electrical control signals to the modulating valve, which responds using solenoids . This valve is responsible for altering the compressed air path when braking by either increasing, maintaining, or releasing the air pressure. Under ice braking conditions the ABS system prevents the affected wheel(s) from locking up by reducing or modulating the air pressure sent to the brake actuator. When accelerating, the ATC system limits slippage of the affected drive wheel by applying air pressure to brake actuators, which helps the vehicle maintain traction and stability. consulab.com info@consulab.com 7 95-HV-125-BWP Orientation, preliminary inspection and system tests Summary Each truck wheel is equipped with a speed sensor that tells the electronic control unit (ECU) how fast the wheel is spin- ning. Under normal conditions: • All wheels rotate at substantially the same speed In a loss-of-traction situation: • One of the drive wheels spins faster or slower • The ECU detects the rotational difference ATC: During the truck acceleration (drive axle) Problems : • A drive wheel is spinning on ice • The truck has difficulty accelerating and shows signs of instability. How does the ATC system respond? • Detects a wheel accelerating too fast • Applies the brakes to the affected wheel • Reduces engine power Results : The truck has better traction ABS: During the truck braking Problems : • A wheel locks up during braking • Risk of losing control of the truck; risk of skidding • Increasing braking distance How does the ABS system respond? • Detects the wheel that is locking up • Releases brake pressure on the affected wheel • Maintains pressure on the affected wheel • Reapplies pressure to affected wheel • The sequence of increasing, maintaining, or releasing occurs several times per second. Results : The wheel keeps on rotating, the truck remains stable consulab.com info@consulab.com 8 95-HV-125-BWP Orientation, preliminary inspection and system tests Questions for students Name : Group : Date : 1. What is the function of the wheel speed sensors? 2. What does any speed difference between the wheels mean when the brakes are not applied? 3. When does the ABS system engage? 4. Why does the ABS system release the brakes on skidding wheels rather than keeping the brakes applied? 5. When does the ATC system engage? 6. What can the ATC system do to stop the truck wheel(s) from spinning? 7. What is the main function of the modulating valve in the ABS and ATC systems? 8. When braking on a low-friction surface, what signal does the EC-80 control unit send to the modulating valve, and how does this valve affect air pressure to prevent wheel lockup? 9. When accelerating on a slippery road causing a drive wheel to spin, what signal does the EC-80 send to the mod- ulating valve, and what does the modulating valve do with the air pressure To the brake chamber of the affected wheel.? 10. What other truck system can cause wheel lock up and how is it controlled? Instructor : Grade : consulab.com info@consulab.com 9 95-HV-125-BWP Orientation, preliminary inspection and system tests SA-3 - Understanding the interaction between the governor and the compressor. Objective After completing this assignment, the student will be able to define the role of the governor in a heavy truck air brake system, to explain the cut-in and cut-out concepts, and to understand how the compressor and the relief valves work. The student should also be able to explain how these components work together to control air production, to prevent overpressure, and to ensure safe operation of the braking system. In addition to managing pressure, the system must also be capable of keeping the compressed air dry and free of debris to protect the components of the pneumatic system. Scenario A heavy truck is traveling in an urban area and makes frequent stops. Every time the driver applies the brakes, air is drawn from the primary and secondary tanks. The system must therefore be able to generate air when the pressure drops, while stopping it once the maximum safe pressure is reached in the tanks. In this assignment, students observe how the air system works using the HV-125 to simulate pressure variations. They must analyze how the governor, compressor and relief valves behave to understand the air pressure system automatic control according to the truck’s needs. In the real world, operating pressures are generally higher on heavy trucks than on the HV-125 trainer. On the HV-125, these pressures have been adjusted to accommodate school facilities, while still clearly demonstrating the basics of the air system operation. Theory Operating the governor and compressor allows for the efficient and safe regulation of air pressure in a heavy truck braking system. This regulation mainly serves to reduce mechanical wear, prevent overpressure, and ensure reliable system operation. To protect the air system against any governor or compressor failure, a relief valve is generally installed on the supply tank or on the air dryer. This valve is set to open at approximately 150 psi, which is higher than the governor’s setting. Governor In a heavy truck, the governor plays a key role in regulating the braking system air pressure. It controls the compressor operation by monitoring the pressure in the reservoirs. Depending on the vehicle configuration, the governor may be integrated into the air dryer or installed directly on the compressor, while performing the same control function. The governor has an internal movable assembly—such as a piston or pneumatic slide valve—actuated by the system’s air pressure. The movement of this mechanism depends on balancing the applied air pressure and the spring force adjust- ment. When the pressure becomes sufficient to overcome the spring force, the piston moves, and when the pressure decreases, the spring pushes the piston to its initial position. As pressure varies, this piston moves and opens or closes air internal paths to different circuits, including the pneumatic signal circuit. consulab.com info@consulab.com 10 95-HV-125-BWP Orientation, preliminary inspection and system tests Cut-in / Cut-out When the air pressure drops to approximately 95 to 100 psi, this refers to the cut-in mode. In this condition, the gover- nor’s internal piston is in rest position, and no pressure is sent to the signal circuit. On the contrary, when the pressure reaches approximately 115 to 120 psi, the governor switches to the cut-out mode. The piston internal movement then opens a passage that allows pressurized air to be routed to the pneumatic control circuit and then to the compressor.. CUT-IN CUT-OUT Air compressor The heavy truck air compressor is equipped with built-in unloader valves in its head. These valves allow the compressor to operate either under load or unloaded condition, depending on the air system’s needs. When a heavy truck air system is in cut-in mode, no pneumatic signal is sent to the control circuit. The compressor’s unloader valves are therefore not activated (↓), allowing the com- pressor to operate under load, compress air, and fill the primary and secondary tanks. When the system switches to cut-out mode, this causes the compressor to unload. This is performed by the unloader valves, which are connected to each other through an internal chamber (or passages) in the compressor head. When the signal is activated (↓), small pneu- matic cylinders keep the valves open, thereby preventing air compression. Air can then flow from one cylinder to another without being compressed, which prevents pressure rising in the tanks. The compressor continues to run, but without compressing air. In a heavy truck compressor, the two cylinder cycles are arranged 180 degrees apart: when one piston is in the com- pression stroke, the other is in the opposite stroke. In cut-out mode, this configuration facilitates the circulation of air between the cylinder chambers inside the compressor rather than sending it to the tanks. This operation reduces mechanical loads, limits wear, and prevents overpressure, thereby ensuring efficient and safe management of the air brake system. consulab.com info@consulab.com 11 95-HV-125-BWP Orientation, preliminary inspection and system tests Air Dryer and Purge Cycle In a heavy truck air brake system, the dryer is used to remove moisture and contaminants from the compressed air be- fore it is stored in the primary and secondary tanks. When the system pressure reaches the cut-out level, the governor transmits the same pneumatic signal sent to the compressor, then triggering the start of the air dryer purge cycle. A purge occurs at the start of each cut-out cycle. Each purge is brief, typically lasting a few seconds (5-35 seconds for AD-HF dryer on the HV-125): the purge valve opens to vent accumulated moisture and contaminants, then closes auto- matically, even if the system remains in cut-out mode. The compressor then stays in discharge state, without producing compressed air, until the system returns to cut-in mode. The air dryer purge typically produces a specific audible noise, which can serve as an audio signal for the system to enter in cut-out mode. However, if the purge cycles occur at very short intervals or repeatedly, it may indicate a mal- function of the system, such as an air leak, excessive air consumption, or improper governor adjustment. Under normal conditions, purge cycles are spaced out and correspond to the actual use of the braking system. consulab.com info@consulab.com 12 95-HV-125-BWP Orientation, preliminary inspection and system tests Questions for students Name : Group : Date : Heavy Truck Air Brake System – HV-125 1. Why is it important to check air pressure in an air brake system? Governor 2. What is the main function of the governor in an air brake system? 3. What information does the governor monitor? 4. Where can the governor be installed on a heavy truck? 5. What is the role of the spring and piston inside the governor? Cut-in 6. What is the cut-in mode? 7. At what pressure does cut-in occur on the HV-125? 8. What happens in the signal circuit during the cut-in mode? 9. What is the compressor state during the cut-in mode? consulab.com info@consulab.com 13 95-HV-125-BWP Orientation, preliminary inspection and system tests Cut-out 10. What is the cut-out mode? 11. At what pressure does cut-out occur on the HV-125? 12. What does the governor do during the cut-out mode? 13. Why does the system stop producing air during cut-out? Compressor and relief valves 14. What is the role of the compressor in the air brake system? 15. What is the role of the compressor relief valves? 16. What happens at the relief valves during the cut-in mode? 17. What happens to the relief valves during the cut-out mode? 18. Why are we saying that the compressor is “unloaded” during cut-out? 19. Does the compressor stop completely during cut-out? Internal Operation of the Compressor 20. How are the compressor cycles arranged in a 2 cylinder compressor? 21. What is the advantage of this cylinder configuration? 22. What happens to the air inside the cut-out compressor? 23. Why is this operation advantageous ? consulab.com info@consulab.com 14 95-HV-125-BWP Orientation, preliminary inspection and system tests Air Dryer and Purge 24. What is the main function of the air dryer? 25. Why is it important to remove moisture? 26. When is the air dryer activated? 27. What is air dryer purging? 28. How long does the air dryer purging last? 29. Does the purge continue as long as the system is in cut-out mode? 30. What specific noise is associated with the air dryer purging? 31. What does repeated purging at short intervals indicate? Summary Question 32. Explain how the governor, compressor, relief valves, and air dryer work together. Instructor : Grade : consulab.com info@consulab.com 15 95-HV-125-BWP Orientation, preliminary inspection and system tests SA-4 - Test One — Pressure Inspection This is a wheels chocked, governor cut-out, low pressure warning and pressure build up test : 1. Drain all tanks to 0 psi. 2. Turn key on. Is the low-pressure warning lamp on? Did the ABS warning come on briefly ? 3. Connect and turn on air supply. 4. Did the low-pressure warning go off above 60 psi ? 5. On a real vehicle with a compressor, the time to build up from 80-100 psi should be within 40 seconds. 6. Governor cut-out is usually 125-135 psi on a truck, (115-120 on the HV-125) 7. Governor cut-in. Drain the system down pressure down to observe the cut-in pressure. The differ- ence between cut-out pressure and cut-in pressure cannot exceed 30 psi. See “Checklist 1” on ®Bendix® document BW1231 for troubleshooting procedures for test 1. Yes No Yes No Yes No Yes No Yes No Yes No Yes No consulab.com info@consulab.com 16 95-HV-125-BWP Orientation, preliminary inspection and system tests SA-5 - Test Two — Leakage Inspection This is a wheels chocked, full pressure test under the following conditions : tractor parking brakes released with the trailer charged (Red and Yellow buttons IN). 1. Allow one minute for the air pressure to stabilize. 2. For two minutes: Watch dash pressure gauges and note any pressure drop. 3. Pressure drops allowed : A. Single vehicle: 4 psi drop within two minutes allowed B. Tractor/trailer: 6 psi drop within two minutes allowed C. Tractor/2 trailers: 8 psi drop within two minutes allowed Correct any errors before moving to the next test. Use this list to guide your troubleshooting of any errors : • Fittings and lines • Tank drain valves • Verify function of low-pressure indicators • Service relays • Parking brake relay • Dual brake valve • Trailer hand valve • Parking brake control • Safety pressure relief valves • Governor operation • Discharge line from the compressor Verify your repairs Yes No Yes No Yes No Yes No Yes No consulab.com info@consulab.com 17 95-HV-125-BWP Orientation, preliminary inspection and system tests SA-6 - Test Three — Chuff Tests This is a wheels chocked, full pressure test under the following conditions: engine stopped, tractor parking brakes released. 1. Apply and hold the brakes. Turn the ignition on and listen for each modulator to “chuff” air as performs its self-tests. In what order do the modulator valves “chuff” ? 2. Number the following list in the order of when they perform their “chuff” test : Drive axle TCV Steering Axle Right Drive Axle Right Additional Axle Right Drive Axle Left Additional Axle Left Steering Axle Left See ®Bendix® Technical Bulletin No. TCH-013-010 - Bendix® ABS “Chuff” Test Performance. OK Not OK consulab.com info@consulab.com 18 95-HV-125-BWP Orientation, preliminary inspection and system tests SA-7 - Test Four — Service Air Delivery Leakage This is a wheels chocked, full pressure test under the following conditions: engine stopped, tractor parking brakes re- leased : 1. Make an 80-90 psi brake application and hold it. 2. Allow one minute for the pressure to stabilize, then watch for a pressure drop over the next two minutes. A. Single vehicle: 4 psi drop within two minutes allowed B. Tractor/trailer: 6 psi drop within two minutes allowed C. Tractor/2 trailers: 8 psi drop within two minutes allowed What is “CVSA” ? What are the various stroke lengths of the brake chambers on the brake board ? What is the “CVSA” stroke adjustment limit for these chambers? Why is this important ? Excessive leakage on the service side of the air system may be caused by the following. Choose all that apply. Discharge line from the compressor Improper governor operation Leaks in service lines and fittings Trailer control valve Tractor protection valve Service brake relay valves Stoplight switch Air Dryer Dual brake valve Double check valves Chamber diaphragms, service and spring brake Spring brake modulating circuits Tank drain valves Trailer hand valve Parking brake control Safety pressure relief valves Yes No Yes No Yes No consulab.com info@consulab.com 19 95-HV-125-BWP Orientation, preliminary inspection and system tests SA-8 - Test Five — Parking Brake Application This is a wheels chocked, full pressure test under the following conditions: engine idling (600-800 rpm). All Vehicles : • Manually operate the park control. Do the parking brakes apply and release promptly? Vehicles with Trailers : • Manually operate the park control. Do the parking brakes on the tractor/trailer apply and release promptly? If performance is slow, check for: • Compromised lines that may have incorrect fittings, kinks, dents or other restrictions. • Spring brake control valve or quick release valve not operating correctly. • Spring brake or service brake chamber damage. • Mechanical issues with foundation brake components. Retest and verify repairs. Yes No Yes No consulab.com info@consulab.com 20 95-HV-125-BWP Orientation, preliminary inspection and system tests SA-9 - Test Six— Dual Circuit System Integrity Including the automatic application of the parking brake and/or the tractor protection valve. Ref : ®Bendix Bulletin TCH-003-051 Bendix® Dash Valve Trip Pressure. This is a wheels chocked, full pressure test under the following conditions: engine stopped, tractor parking brakes re- leased : 1. Drain completely the secondary reservoir (front axle). A. Did the primary reservoir retain most of its pressure ? B. Did the trailer system remain charged ? C. Did the Tractor and trailer brakes apply ? 2. Make a brake application with the secondary reservoir empty. A. Do the rear axle brakes reply and release normally ? B. Trailer brakes (if connected) apply and release normally ? 3. Testing for “pop” pressure. A. Install known good pressure test gauge in the secondary reservoir. B. Operate engine to “cut-out” pressure. Stop engine. C. Completely drain the primary reservoir. D. Drain the secondary reservoir at a rate of approximately 20-50 psi/minute. E. Note the pressure when the parking control “pops”. What pressure is it “supposed” to pop out at? (see Bendix® Bulletin TCH-003-051) 4. Testing the tractor protection valve. A. Make sure that the trailer is “charged”, red knob pushed in, and build air to governor cut- out. B. Disconnect the service/control line to the trailer. C. Point the glad-hand in a safe direction and restrain from moving. Make and hold a full ser- vice application. D. Note the pressure drop and record the pressure that the red knob of the tractor protection valve “pops”. E. Observe and record the pressures indicated in the primary and secondary reservoirs. Verify that the supply/emergency circuit has vented to atmosphere. 5. Recharge the system to governor cut-out and drain the primary reservoir. A. Does the secondary reservoir retain most of its pressure ? B. The trailer system should remain charged. Did it ? 6. Drain completely the primary reservoir, then apply and release the brakes. A. Do the front axle brakes apply and release ? B. With the trailer hooked up the trailer brakes should apply and release. Do they ? C. Trucks, towing trucks and busses typically have a spring brake modulating valve. The rear axle brakes should apply and release by exhausting air from the spring brake chambers. Does it ? Verify all repairs. Yes No Yes No Yes No Yes No Yes No Yes No Yes No Yes No Yes No Yes No Yes No Yes No Yes No Yes No Yes No Yes No Yes No Yes No Yes No Yes No consulab.com info@consulab.com 21 95-HV-125-BWP Orientation, preliminary inspection and system tests SA-10 - Checklist Six After following all of these tests and checklists you should be able to eliminate any failures. In the event that you still are not able to pass the system checks we recommend that you review the basic structure of the system. It may be that just one thing may have been overlooked. Be sure to carefully inspect the following items : • Are the fittings, lines, and hoses in good operating condition and D.O.T. approved ? • Verify the pressure protection valve circuits. What are they protecting ? • Does the tractor protection valve function to protect the tractor over the trailer ? • Does the control valve operating the tractor protection valve also function properly ? • When parking, does the parking control valve function correctly ? • When parking the trailer, does the trailer spring brake control valve function as designed ? • Have the double check valves been verified to hold air in both directions ? • Do the relay valves operate and exhaust properly ? Assignments up until now have been tests and checklists. At the completion of this assignment you will be moving on to various troubleshooting assignments. Now you will use the tests and checklists, done in the previous eight assignments to find various faults that have been inserted into the system. consulab.com info@consulab.com 22 95-HV-125-BWP Truck faults Truck faults SA-11 - HV-125-BWP Truck Pneumatic Fault F1 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your bobtail fleet tractors is currently being held at the weigh scale. This is due to failing a brake inspection. It was observed and reported that the drive axle service brakes were not operating properly. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use the gauges and disconnect tubes to take pressure measurements. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 23 95-HV-125-BWP Truck faults SA-12 - HV-125-BWP Truck Pneumatic Fault F2 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your bobtail fleet tractors is currently being held at the weigh scale. This is due to failing a brake inspection. It was observed and reported that the drive axle service brakes were not operating properly. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use the gauges and disconnect tubes to take pressure measurements. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 24 95-HV-125-BWP Truck faults SA-13 - HV-125-BWP Truck Pneumatic Fault F3 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your bobtail fleet tractors is currently being held at the weigh scale. This is due to failing a brake inspection. It was observed and reported that the drive axle service brakes were not operating properly. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use the gauges and disconnect tubes to take pressure measurements. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 25 95-HV-125-BWP Truck faults SA-14 - HV-125-BWP Truck Pneumatic Fault F4 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your bobtail fleet tractors is currently being held at the weigh scale. This is due to failing a brake inspection. It was observed and reported that the drive axle service brakes were not operating properly. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use the gauges and disconnect tubes to take pressure measurements. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 26 95-HV-125-BWP Truck faults SA-15 - HV-125-BWP Truck Pneumatic Fault F5 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your fleet tractor trailer combinations is currently being held at the weigh scale. This is due to failing a brake inspection. It was observed and reported that trailer hand valve will not operate the trailer brakes. During your inspection and testing you find that the trailer brakes operate with the foot valve, but not the trailer hand valve. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are- only to identify the problem. You may use gauges and disconnect tubes to take pressure measurements. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 27 95-HV-125-BWP Truck faults SA-16 - HV-125-BWP Truck Pneumatic Fault F6 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your fleet tractor trailer combinations is currently being held at the weigh scale. This is due to failing a brake inspection. It was observed and reported that the tractor drive axle brakes do not operate when applied with the foot valve. The steering axle brakes are operating correctly. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use the gauges and disconnect tubes to take pressure measurements. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 28 95-HV-125-BWP Truck faults SA-17 - HV-125-BWP Truck Electrical Fault F1 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. On a routine maintenance scan with a scan tool the technician was not able to communicate with the vehicle through the Deutsch 9 pin “Diagnostic Connector” on the dash. The vehicle was handed off to you for troubleshooting of this com- munication issue. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use all of the testing tools available. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 29 95-HV-125-BWP Truck faults SA-18 - HV-125-BWP Truck Electrical Fault F2 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. On a routine maintenance scan with a scan tool the technician was not able to communicate with the vehicle through the Deutsch 9 pin “Diagnostic Connector” on the dash. The vehicle was handed off to you for troubleshooting of this com- munication issue. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use all of the testing tools available. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 30 95-HV-125-BWP Truck faults SA-19 - HV-125-BWP Truck Electrical Fault F3 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. On a routine maintenance scan with a scan tool a technician noted some fault codes relating to the truck braking sys- tem. The vehicle was handed off to you for troubleshooting of these codes. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use all of the testing tools available. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 31 95-HV-125-BWP Truck faults SA-20 - HV-125-BWP Truck Electrical Fault F4 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your bobtail fleet tractors is currently being held at the weigh scale. This is due to failing a brake inspection. It was observed and reported that there is an illuminated ABS light on the dash. You have been sent to troubleshoot the problem with a scan tool, breakout box and access to wiring schematics. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use all of the testing tools available. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 32 95-HV-125-BWP Truck faults SA-21 - HV-125-BWP Truck Electrical Fault F5 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your bobtail fleet tractors is currently being held at the weigh scale. This is due to failing a brake inspection. It was observed and reported that there is an illuminated ABS light on the dash. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use all of the testing tools available. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 33 95-HV-125-BWP Truck faults SA-22 - HV-125-BWP Truck Electrical Fault F6 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your bobtail fleet tractors is currently being held at the weigh scale. This is due to failing a brake inspection. It was observed and reported that the ATC light is illuminated. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use all of the testing tools available. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 34 95-HV-125-BWP Truck faults SA-23 - HV-125-BWP Truck Electrical Fault F7 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your bobtail fleet tractors is currently being held at the weigh scale. This is due to failing a brake inspection. It was observed and reported that both the ABS and ATC lights are illuminated on the dash. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use all of the testing tools available. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 35 95-HV-125-BWP Truck faults SA-24 - HV-125-BWP Truck Electrical Fault F8 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your bobtail fleet tractors is currently being held at the weigh scale. This is due to failing a brake inspection. It was observed and reported that both the ABS and ATC lights are illuminated on the dash. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use all of the testing tools available. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 36 95-HV-125-BWP Truck faults SA-25 - HV-125-BWP Truck Electrical Fault F9 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your fleet tractor-trailer units is currently in the shop for routine maintenance. One of the maintenance checks is to communicate with the trailer brake controller and check for codes. The trailer brake controller does not appear to be initiating its self-test routine, and the diagnostic software will not communicate with the comm adapter or the laptop. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use all of the testing tools available. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 37 95-HV-125-BWP Truck faults SA-26 - HV-125-BWP Truck Electrical Fault F10 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. On a routine maintenance scan with a scan tool the technician was not able to communicate with the vehicle through the Deutsch connector on the dash. The vehicle was handed off to you for troubleshooting of this communication issue. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use all of the testing tools available. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 38 95-HV-125-BWP Truck faults SA-27 - HV-125-BWP Truck Electrical Fault F11 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your bobtail fleet tractors is currently being held at the weigh scale. This is due to failing a brake inspection. It was observed and reported that there is an active fault in the ABS system and that the warning light is illuminated. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use all of the testing tools available. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 39 95-HV-125-BWP Truck faults SA-28 - HV-125-BWP Truck Electrical Fault F12 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your bobtail fleet tractors is currently being held at the weigh scale. This is due to failing a brake inspection. It was observed and reported that there is an active fault in the ABS system and that the warning light is illuminated. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use all of the testing tools available. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 40 95-HV-125-BWP Truck faults SA-29 - HV-125-BWP Truck Faulted Component #1 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your bobtail fleet tractors is currently being held at the weigh scale. This is due to failing a brake inspection. It was observed and reported that one of the tractor service brakes was not operating properly. The report stated that “One service chamber applies slower than the others”. The position was not noted in the information from the driver. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use all of the testing tools available. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 41 95-HV-125-BWP Truck faults SA-30 - HV-125-BWP Truck Faulted Components #2 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your bobtail fleet tractors is currently being held at the weigh scale. This is due to failing a brake inspection. It was observed and reported that one of the modulator valves was leaking on a service brake application. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use all of the testing tools available. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 42 95-HV-125-BWP Truck faults SA-31 - HV-125-BWP Truck Faulted Component #3 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your bobtail fleet tractors is currently being held at the weigh scale. This is due to failing a brake inspection. It was observed and reported that there is a leak from the exhaust port of the ATR-6 valve when the parking brakes are released. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use all of the testing tools available. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 43 95-HV-125-BWP Truck faults SA-32 - HV-125-BWP Truck Faulted Component #4 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your bobtail fleet tractors is currently being held at the weigh scale. This is due to failing a brake inspection. It was observed and reported that the drive axle service brakes are slow to apply compared to the steering axle brakes. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use all of the testing tools available. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 44 95-HV-125-BWP Trailer faults Trailer faults SA-33 - HV-125-BWP Trailer Fault #1 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. On a routine maintenance inspection with a scan tool the technician was not able to communicate with the trailer through the Deutsch connector on the dash. Additionally, the trailer ABS light may not be operating properly. The vehicle was handed off to you for troubleshooting of this communication issue. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use the gauges and disconnect tubes to take pressure measurements. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 45 95-HV-125-BWP Trailer faults SA-34 - HV-125-BWP Trailer Fault #2 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. This trailer was held at an inspection station because of an illuminated trailer ABS lamp. You may use a scan tool to troubleshoot this issue. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use the gauges and disconnect tubes to take pressure measurements. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 46 95-HV-125-BWP Trailer faults SA-35 - HV-125-BWP Trailer Fault #3 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. This trailer was held at an inspection station because of an illuminated trailer ABS lamp. You may use a scan tool to troubleshoot this issue. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use the gauges and disconnect tubes to take pressure measurements. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 47 95-HV-125-BWP Trailer faults SA-36 - HV-125-BWP Trailer Fault #4 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. During a routine maintenance scan, it was found that the scan tool would not communicate with the trailer ABS unit. Locate the cause. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use the gauges and disconnect tubes to take pressure measurements. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 48 95-HV-125-BWP Trailer faults SA-37 - HV-125-BWP Trailer Fault #5 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. This trailer was held at an inspection station because of an illuminated trailer ABS lamp. You may use a scan tool to troubleshoot this issue. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use the gauges and disconnect tubes to take pressure measurements. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 49 95-HV-125-BWP Trailer Faults SA-38 - HV-125-BWP Trailer Fault #6 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your fleet tractor/trailer combinations is currently being held at the weigh scale out of service. This is due to fail- ing a brake inspection. It was observed and reported that there is air leaking from the trailer antilock relay valve when the trailer parking brakes are released Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use the gauges and disconnect tubes to take pressure measurements. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 50 95-HV-125-BWP Trailer faults SA-39 - HV-125-BWP Trailer Fault #7 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your fleet tractor/trailer combinations is currently being held at the weigh scale out of service. This is due to failing a brake inspection. It was observed and reported that the trailer brakes do appear to apply. NOTE : This assignment needs instructor set up along with a short briefing and demonstration for you to continue with this fault. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use the gauges and disconnect tubes to take pressure measurements. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 51 95-HV-125-BWP Trailer faults SA-40 - HV-125-BWP Trailer Fault #8 You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your fleet tractor/trailer combinations is currently being held at the weigh scale out of service. This is due to failing a brake inspection. It was observed and reported that one of the roadside trailer brakes does not operate. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use the gauges and disconnect tubes to take pressure measurements. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 52 95-HV-125-BWP Faulted wheel speed sensor Faulted wheel speed sensor SA-41 - HV-125-BWP Wheel Speed Sensor You are a working technician in a HD fleet maintenance facility; working on vehicles covered under U.S. D.O.T., and Transport Canada regulations. You are well aware of the Commercial Vehicle Safety Alliance out-of-service guidelines for over the road vehicles as well. One of your fleet tractor-trailer combinations is currently being held at the weigh scale. This is due to failing a brake inspection. It was observed and reported that the trailer ABS light is illuminated. Your job is to locate the cause of the problem and report back to the shop before you try to repair anything. You are only to identify the problem. You may use the gauges and disconnect tubes to take pressure measurements. Be specific…you need to pinpoint exactly where the problem is located. Hand draw the location, clearly labeled in the space below to be filed in the master equipment file for this unit number. consulab.com info@consulab.com 53 95-HV-125-BWP Notes Notes 400-6330 Zéphirin-Paquet St. Québec QC G2C 0M3 Canada © ConsuLab Educatech Inc, 2023. All rights reserved. Introductory material Description Application Educational Advantages Orientation, preliminary inspection and system tests Assignment 1 : Component locations, and color coding the HV-125-BWP SA-2: Understanding how ABS and ATC systems work. Questions for students SA-3: Understanding the interaction between the governor and the compressor. Questions for students SA-4 - Test One — Pressure Inspection SA-5 - Test Two — Leakage Inspection SA-6 - Test Three — Chuff Tests SA-7 - Test Four — Service Air Delivery Leakage SA-8 - Test Five — Parking Brake Application SA-9 - Test Six— Dual Circuit System Integrity SA-10 - Checklist Six Truck faults SA-11 - HV-125-BWP Truck Pneumatic Fault F1 SA-12 - HV-125-BWP Truck Pneumatic Fault F2 SA-13 - HV-125-BWP Truck Pneumatic Fault F3 SA-14 - HV-125-BWP Truck Pneumatic Fault F4 SA-15 - HV-125-BWP Truck Pneumatic Fault F5 SA-16 - HV-125-BWP Truck Pneumatic Fault F6 SA-17 - HV-125-BWP Truck Electrical Fault F1 SA-18 - HV-125-BWP Truck Electrical Fault F2 SA-19 - HV-125-BWP Truck Electrical Fault F3 SA-20 - HV-125-BWP Truck Electrical Fault F4 SA-21 - HV-125-BWP Truck Electrical Fault F5 SA-22 - HV-125-BWP Truck Electrical Fault F6 SA-23 - HV-125-BWP Truck Electrical Fault F7 SA-24 - HV-125-BWP Truck Electrical Fault F8 SA-25 - HV-125-BWP Truck Electrical Fault F9 SA-26 - HV-125-BWP Truck Electrical Fault F10 SA-27 - HV-125-BWP Truck Electrical Fault F11 SA-28 - HV-125-BWP Truck Electrical Fault F12 SA-29 - HV-125-BWP Truck Faulted Component #1 SA-30 - HV-125-BWP Truck Faulted Components #2 SA-31 - HV-125-BWP Truck Faulted Component #3 SA-32 - HV-125-BWP Truck Faulted Component #4 Trailer faults SA-33 - HV-125-BWP Trailer Fault #1 SA-34 - HV-125-BWP Trailer Fault #2 SA-35 - HV-125-BWP Trailer Fault #3 SA-36 - HV-125-BWP Trailer Fault #4 SA-37 - HV-125-BWP Trailer Fault #5 SA-38 - HV-125-BWP Trailer Fault #6 SA-39 - HV-125-BWP Trailer Fault #7 SA-40 - HV-125-BWP Trailer Fault #8 Faulted wheel speed sensor SA-41 - HV-125-BWP Wheel Speed Sensor
