When applying for the air brake endorsement taking a written test, the first thing to do is to verify that you meet the requirements for sitting for the written test. Vehicle inspectors bulletin vib 14 test procedures for air brake. Class 8 truck tractor braking performance improvement study. Enter the vehicle on the driver side, and locate the red and yellow knobs on your dash. Gritt 1062002 diagonal split system in a diagonal split system, one brake line is run to each rear brake and one to each front brake. Apply steady pressure to the brake pedal and let the air tanks settle. There are 6 basic components on an air brake equipped vehicle. And the foundation brakes can be any of the following. For trucktrailer combinations equipped with hand controls, ensure that.
It has a separate relay box with electric components. Pulls the brake shoes away from the drum and allows the wheels to roll freely c. Most heavyduty vehicles use dual air brake systems for safety. A dual air brake system has 2 separate air brake systems, which use a single set of brake controls. Summary of brake rating test resultstrucks and buses 6.
Parking brake tests on airbraked heavy truck and tractors. Commercial trucks drivers, from time to time, are stopped by the department of transportation dot and asked to perform an air brake test to assure maximum safety of the braking system. If you want to drive a truck or bus with air brakes, or pull a trailer with air brakes, you need to read this section. Truck tractor trailer air brakes general air brake maintenance and tolerance randy price brake and wheel end education as a result of the changes to federal motor carrier safety regulation 49cfr part 393. Maintenance will be needed the pressure mounts at 150 psi. These questions and answers were written by professional authors with extensive knowledge and experience in the. Brake test procedures air operated brakes this system is operated by air from a compressor off the engine. Make sure you place one at the front of the truck, in front of the tire and once at the back of the truck, behind the tire. Read each question carefully and select the answer that best answers the question. Table of contents federal motor carrier safety administration. Air brakes test practice introduction this study guide contains one hundred ten commercial drivers license air brakes test questions and answers. Reduce your speed and test the remaining system while underway. The first 12 are specific free practice exams and the last one below is general to all areas.
A straight truck or bus air brake system cannot leak. Gritt 1 1062002 an introduction to brake systems sae brake colloquium october 6th 2002 daimlerchrysler this presentation was originally created as a one hour lecture class. The truck brake configurations were also evaluated for stopping performance and stability on a straight, wet splitcoefficient surface. The vlt series of roller brake testers for heavy vehicles come with level rollers to allow bidirectional testing as the pit is so short. Scroll down to download 7 step air brake test cheat sheet pdf. You should have an understanding of the parking brake. Continue to repeatedly press the brake pedal, between 40psi 20psi both valves will pop out. The truckbrake configurations were also evaluated for stopping performance and stability on a straight, wet splitcoefficient surface. My rudolf limpert leonard segel wway safety research institute the university of michigan ann arbor repared for national highway traffic.
To check the free play of manual slack adjusters of scam brakes you should. Your truck or bus has a dual air brake system, if a low air pressure warning comes on for only one system, what should you do. Each system has its own air tanks, hoses, lines, etc. In conclusion, this test procedure measured differences between all three vehicles with very high statistical certainty. The purpose of the inspection is to make sure the brakes do not leak, that the slack adjusters are adjusted properly and that the. Further, the inspection and test results have been recorded on the inspection form. Take one of our 12 free 2019 ase practice tests below to see what type of questions appear on an ase auto mechanic certification exam. Reduce your speed and drive to the nearest garage for repair. To test air system integrity, make and hold a full brake application for at least 2 minutes while watching the air pressure gauge with the engine off, the key in the on position, and the park brake off. How to do the cdl air brake pretrip inspection youtube. If you plan to drive a truck that requires the use of air brakes, you must take the air brake test as part of getting your cdl. In addition, test conditions on site particularly speed and gradient may be much less onerous than those used in iso 3450, which produces low test results. To test the service brakes, release all the brakes while covering the foot brake of course. The pressure quickly increases in the brake chambers and applies force to.
If you want to pull a trailer with air brakes, you also need. Start the truck, build pressure back up to 120psi, air pressure release valve will pop off. Put the truck into low gear, check to see that the area ahead is clear and slowly get the truck moving forward. A manual or automatic drain valve must be fitted at the lowest point of each. Test may be different if truck has 2 axles, you would skip 3rd truck axle. Guidance on brake testing for rubbertyred vehicles pdf hse. The overall outcome of which may be a poor brake test result, but one that exceeds a low level pass criterion and is not, therefore, seen as a test failure. How to perform an air brake test firefightertoolbox. Fan the brake pedal to continue bleeding air from the system and observe the apv automatically engages the parking brake. Which of the following is okay to find in the air brake system.
The air brake test will consist of a leakdown test to make sure your air brakes arent leaking air and losing pressure. Truck tractor trailer air brakes general air brake. The air disc brake configuration showed better performance in this test over the other configurations for stopping efficiency. After you get the truck moving, push in the clutch and apply the foot brake. One system typically operates the regular brakes on the rear axle or axles. On a test track in the new volvo fh, together with test drivers you get to experience how the collision warning with emergency brake system can avoid a rear end collision, even if its tight. You should then verify the amount of fees you are required to pay as you apply.
Pretrip inspection class b checklist items and video. Study cdl air brakes practice test and applying for the for the air brake endorsement. If you can read this, you have adobe acrobat reader installed on your computer. Controls the flow of air into each of the brake chambers b. Forces the brake shoes against the inside of the brake drum 5. At the end of this checklist scroll to the bottom of this page, you will find a procedural video to assist you in understanding the requirements for successfully completing the class b dump truck pretrip inspection. An air brake endorsement is only required if your vehicle needs a cdl. Air brakes test cdl test answers driver license test. It is intended compliance with this manual will help ensure the modified vehicle or icv. The air brake test covers the different braking systems and tests you on your knowledge of parking brakes, service brakes, emergency brakes, reading low pressure warnings, checking pressure gauges, and more. The brake test truek brake test truck with diaphragm cocks functions of cocks, couplings, and triple hose. The braking systems have been inspected, tested, and found to conform with applicable requirements contained in the referenced standards and on attached brake performance test record form. Each vehicle is scored on the average deceleration rate it.
The brake pedal is spongy when pressure is applied c. Most recertification tests are about half the length of the regular tests. Vehicles must be fully loaded before being rollerbrake tested because the grip between the tyre and the rollers is more effective that way. Since the brake systems were not torque limited on this surface, these findings. Record of performance inspection and brake testonhighway. A straight truck or bus air brake system would not leak at a rate of more than how. Record of performanceinspection and brake testoffhighway. Vehicles must be fully loaded before being roller brake tested because the grip between the tyre and the rollers is more effective that way. The most important part of the pretrip inspection is the 7 step air brake test.
Nonexempt onhighway trucks, truck tractortrailer combinations, transmix trucks, dump trucks, buses. Free cdl air brakes endorsement practice test questions. Our ase practice test materials were written by dr. Repeatedly press the brake pedal, air pressure will drop, warning light comes on at 60psi. The connections are such that the left front and the right rear brake are on one circuit and. When the brakes are applied, the brake shoes or linings are pressed against the. Cdl air brake test air brake practice test in order to operate a bus or truck that has air brakes, you will be required to learn the information contained in the dmvs cdl air brakes section of the study manual. I made this when i was studying for my cdl 20 years ago and it still works today. These questions and answers were written by professional authors with extensive knowledge and experience in the transportation industry. Air brakes use compressed air to make the brakes work.
Oct 17, 2017 this feature is not available right now. Summary of brake rating test results trucks and buses 6. To be eligible for cdl air brake test, you should understand how air is maintained and the constant pressure to drive under. Memorize the following 7 steps to pass any air brakes dmv test questions this works guaranteed. Inspection of air brakes is must know for a cdl license watch the video.
How to pass air brakes during road skills and cdl permit test. Mediumheavy truck tests this study guide contains test specifications, task lists, and sample questions for the following ase tests. Brake testing brake test objective determine the deceleration rate attained by each test vehicle on twelve 60 0 mph impending skid threshold stops, with abs in operation if the vehicle is so equipped. An auto mechanic can get certified by taking the automotive service excellence ase exams, covering fourteen different subject areas, such as diesel and gas engines. Parking brake tests on airbraked heavy truck and tractors minimum initial service brake pressure this document is available to the public from the national technical information service, springfield, va 22161. Bus, truck, tractortrailer braking system performance volume 2 of 2.
The brake when you use the brake pedal during normal driving. Brake testing methodology study driver effects testing. Test summary, performance of vehicles equipped with advanced systems on dry tra. Its a free practice exam to study before you take the real exam at your states local dmv and get your cdl permit. Assessment based on installation checklist and data from a static brake test machine application of a series of road tests. The official ase study guide ase mediumheavy truck tests. This test must be taken by all cdl applicants desiring. When the system falls below approximately 60 psi, the brakes are automatically locked by springs and the bus becomes immobile. Take truck driver safety seriously and consider the hefty consequences of reckless driving. Under ideal conditions, a truck with air brakes going 55 mph would require a stopping distance of.
This test must be taken by all cdl applicants desiring to operate equipment with air brakes. Test summary, performance of vehicles equipped with advanced. Summary of air brake response time teststractortrailer combinations 8. Brake test truck with key cocks testing the brake test truck code of tests. A commercial driver must perform a pretrip inspection before taking a truck trailer on any public road. Weve helped thousands of students get their cdl license, endorsements and start other skilled trade careers. Fitting functions of the valves testing the brake test truck code of tests. The three phases of tests presented here have been designed to discover the presence of both vacuum and hydraulic fluid leakage and sluggish performance of the brakes. Each vehicle is scored on the average deceleration rate it attains. Hino diesel and mitsubishi fuso truck enginespowers the glow plug to test the plug in its operating state. Jan 16, 20 on a test track in the new volvo fh, together with test drivers you get to experience how the collision warning with emergency brake system can avoid a rear end collision, even if its tight.
1098 812 358 580 1009 1282 1181 1402 887 608 653 454 753 169 521 1159 1347 777 1398 68 1656 869 1557 1344 741 277 652 1069 873 1350 1035 1032 170 1437 258 1085