hydraulic brake test on school bus

If the vehicle is equipped with an adjustable engine speed governor, it is adjusted according to the manufacturer's recommendation. School Bus 101 9.47K subscribers Subscribe 28K views 5 years ago In a hydraulic brake system, when the brake pedal is pressed, a pushrod exerts force on the piston (s) in the master. 0000002264 00000 n Since most large trucks have air brakes then why not large school buses. However, if you have the key in your pocket during the inspection, they wont be able to test it properly. 6 11 This will help you identify any areas where fluid may be leaking from the system. If there are no leaks in the system, you should see the needle on the pressure gauge rise steadily during this time. A split-second delay in brake reaction is present in all air brake systems. Check the hydro-boost for leaks. Words in addition to those required by Standard No. Make three stops from 30 mph at 10 fpsps for each stop. title 49 of the Code of Federal Regulations, 7. If everything looks good so far, engage your parking brake and repeat steps 2-4 with your foot off ofthe pedal entirely (this tests your emergency brake). Spring pressure c. Air pressure d. Any of the above 2. Drive for 1.5 mi at 40 mph after the last snub and immediately follow the recovery procedure specified in S7.11.3.2. Pressure component means a brake system component that contains the brake system fluid and controls or senses the fluid pressure. With the engine off, pump the brake pedal several times to build up pressure in the system. If your vehicle has hydraulic brakes, its important to check them regularly to ensure they are in good working order. Remove old certificate. 3) Here are the types of tests that must be conducted on a typical air brake system: a) The Governor Cut in/Cut out test is to make sure that the governor is applying or cutting off air pressure to the air reservoir tanks as needed. (c) Of a color that contrasts with its background, if it is not engraved or embossed. S5.1.5 Water recovery. Any brake fluid or power steering fluid leak A Foot or service brakes distance shall, at all times, be . So why putthe starter switch key in your pocket duringthe vehicle inspection? The parking brake test surface is clean, dry, smooth, Portland cement concrete. Third effectiveness (lightly loaded vehicle), 10. S7.11.3.1 Vehicles with GVWR of 10,000 lb or less. S5.1.2.3 For a vehicle manufactured with a service brake system in which the brake signal is transmitted electrically between the brake pedal and some or all of the foundation brakes, regardless of the means of actuation of the foundation brakes, the vehicle shall be capable of stopping from 60 mph within the corresponding distance specified in Column IV of Table II with any single failure in any circuit that electrically transmits the brake signal, and with all other systems intact. S5.3.4 When an indicator lamp is activated it may be steady burning or flashing. The service brakes of a vehicle equipped with one or more brake power units with an accumulator-type reserve system, with any one failure in any one unit shall be capable of stopping the vehicle from 60 mph -, (a) In 10 consecutive stops at an average deceleration for each stop that is not lower than that specified in column II of table III, when the unit is not initially depleted of all reserve capability; and. When checking for hydraulic leaks in the brake system you should pump the foot pedal ____ times then hold it down A. Spike stop means a stop resulting from the application of 200 lbs of force on the service brake control in 0.08 s. Split service brake system means a brake system consisting of two or more subsystems actuated by a single control, designed so that a single failure in any subsystem (such as a leakage-type failure of a pressure component of a hydraulic subsystem except structural failure of a housing that is common to two or more subsystems, or an electrical failure in an electric subsystem) does not impair the operation of any other subsystem. will bring you to those results. a. Nomenclature changes to part 571 appear at 69 FR 18803, Apr. This document is available in the following developer friendly formats: Information and documentation can be found in our 2389 turbine oil, the motor weighs approximately 225 pounds. to 150 F. Why Hydraulic Brakes Do Not Work If Bubbles of Air Leak into the Liquid? There's a reason big rigs have air brakes! %PDF-1.4 % Comments are moderated and may not appear for 24 hours or more. or less shall be capable of making 10 spike stops from 30 mph, followed by 6 effectiveness (check) stops from 60 mph, at least one of which shall be within a corresponding stopping distance specified in column I of table II. Are their school bus drivers that prefer one over the other? B. As for brakes, I think any bus longer than 6 rows should have air. Restore system to normal at completion of this test. The flow switch is the switch on the booster side of he brake system. Some people will disagree with me. Start the engine and run at idle speed. S6.9.1 For vehicles with a GVWR of 10,000 pounds or less, road tests are conducted on a 12-foot-wide, level roadway, having a skid number of 81. S5.1.3.2 Brake power assist units. site when drafting amendatory language for Federal regulations: A separate drafting site They feel sooooo much more confident in a heavy vehicle. %PDF-1.4 % (including driver and instrumentation); (b) For vehicles with a GVWR greater than 10,000 lbs., unloaded vehicle weight plus 500 lbs. It is in keeping with a concern for safety that the four-wheel disc brake system has become the brake of choice for the school bus industry. Taking the bus to school involves walking to the bus stop. The choice of this option must not be construed as adding to the requirements specified in S5.1.2 and S5.1.3.) Next, start the engine and let it idle for a few minutes to warm up the hydraulic fluid. Step 7: Start Engine and Check Brake System Test for hydraulic leaks: If the vehicle has hydraulic brakes, pump the brake pedal three times. Preventing these and other school bus brake issues can be as simple as bringing your school buses to us to inspect, maintain, and repair. S7.4.1.1 Burnish. Why yes, the ORIGinal CHARGER is a Fastback. Control force readings may be terminated when vehicle speed falls to 5 mph. 0000000016 00000 n (b) At vehicle speeds of 10 mph or less, any wheel may lock up for any duration. S5.1.4.1 The control force used for the baseline check stops or snubs shall be not less than 10 pounds, nor more than 60 pounds, except that the control force for a vehicle with a GVWR of 10,000 pounds or more may be between 10 pounds and 90 pounds. Each school bus with a GVWR greater than 10,000 pounds manufactured on or after March 1, 1999 shall be capable of meeting the requirements of S5.1.1 through S5.1.5, under the conditions prescribed in S6, when tested according to the procedures and in the sequence set forth in S7. Explanation To test hydraulic brakes, you should pump the brake pedal three times, then apply firm pressure to the brake pedal and hold for five seconds. 9, 2004. The second test is a flow check. Gently pull against the brake by releasing the clutch, and it should hold the vehicle. The Electronic Code of Federal Regulations (eCFR) is a continuously updated online version of the CFR. Then (for passenger cars) make four stops from either 95 mph if the speed attainable in 2 mi is 99 to (but not including) 104 mph, or 100 mph if the speed attainable in 2 mi is 104 mph or greater. are closed except as required for instrumentation purposes. attacks or slurs, hate speech, demonstrably false information, excessive profanity, or that are thinly veiled promotions for a product, will not be approved. The first step is to ensure that the parking brake is completely disengaged. Please do not provide confidential The third test is a leaks check. Some have air brakes but most operators have hydraulic.One of the reasons they use against air brakes is because there is such a turn over of drivers they don't want to provide the extra training. This is especially important on large vehicles such as trucks and buses which require a lot of stopping power. (Only for vehicles that have been tested according to S7.7.2.) If the propulsion batteries are depleted during a test sequence such that the vehicle reaches automatic shut-down, will not accelerate, or the low state of charge warning lamp is illuminated, the vehicle is to be accelerated to brake test speed by auxiliary means. Pump the brakes until the . S7.11.3.2 Vehicles with GVWR greater than 10,000 lb. Release the spring brake and get the bus moving very slowly. Right Side of School Bus . (This test need not be run if the option in S7.10.2 is selected.) Hydraulic or Air Brakes? All was good according to them. To avoid engine stall during tests required to be run in gear a manual transmission may be shifted to neutral (or the clutch disengaged) when the vehicle speed decreases to 20 mph. Unless otherwise specified the brake temperature is 150 F. Reverse Lights - clean, not missing or broken . Top Member, ihthomas665spd For vehicles with parking brake systems not utilizing the service brake friction elements, burnish the friction elements of such systems prior to parking brake tests according to the manufacturer's published recommendations as furnished to the purchaser. S2. Its a 34' Freightliner Thomas. Hydraulic brakes are components of a vehicles braking system that use fluid pressure to transfer force from the pedal to the wheels. Use a full brake application for the duration of the stop, with the clutch pedal depressed or the transmission selector control in the neutral position, for the duration of each stop. Apply and hold the service brakes for a minute. S5.2.2.2 The vehicle's parking brake, with the parking mechanism not engaged, shall be capable of holding the vehicle stationary for 5 minutes, in both forward and reverse directions, on a 20 percent grade. 8 0 obj<>stream The brake pedal should not move (depress) during the five seconds. 0000000516 00000 n The Federal Motor Carrier Safety Administration (FMCSA) has developed and issued standards for State testing and licensing of CDL holders. 39.00 Hydraulic Brakes 2. Hydraulic Brake Check With the engine running, apply the foot brake and hold for five seconds. Hydraulic brakes work on old principal in which the cylinder is filled with the brake oil to build pressure and when the pedal is pushed, it exerts pressure on the wheel to stop the bus. Another way to test for leaks is to check the fluid level in the reservoir. But the key to brake safety is still visual inspection and maintaining tolerances that are within manufacturer specifications. Hydraulic Brake Check Pump the brake pedal three times, then hold it down for five seconds. Establish an initial brake temperature before the first brake application of 130 to 150 F. Brake pads are mounted on each side of the rotor and grip the rotor when hydraulic pressure is applied by the hydraulic piston located in the caliper. Each truck and bus (other than a school bus) with a GVWR of 4,536 kg (10,000 pounds) or less which is subject to this part and school buses with a GVWR greater than 4,536 kg (10,000 pounds) shall be equipped with a parking brake system as required by FMVSS No. S6.13 Control forces. 3. What's The Best Cordless Vacuum For RVers? I have been a medium duty bus tech for decades. S5.2.2.1 The vehicle's parking brake and parking mechanism, when both are engaged, shall be capable of holding the vehicle stationary (to the limit of traction of the braked wheels) for 5 minutes, in both forward and reverse directions, on a 30 percent grade. Required fields are marked *. 1/1.1 If you do not pull down hard enough, then the trailer could continue to roll even after you have applied the brakes. I couldnt tell exactly on my rears but thought it almost looked drum.. but I guess in 2000 it was not dont that way anymore so I probably have disc on that hydro bus. Bookmark +. S7.3 Service brake system - first (preburnish) effectiveness test. Stopping distance means the distance traveled by a vehicle from the point of application of force to the brake control to the point at which the vehicle reaches a full stop. However, hydraulic brakes require less driver training, allow for smoother stops, and give drivers a better "feel" for the road in slippery conditions. result, it may not include the most recent changes applied to the CFR. Make three stops from 30 mph at 10 fpsps for each stop. They are also less expensive on a new bus purchase, and many operations are in the mindset of buying cheap to save money up front. Release the spring brakes. Test procedure and sequence. 0000000656 00000 n (a) The parking brake system on a multipurpose passenger vehicle, truck or bus (other than a school bus) with a GVWR of 4,536 kilograms (10,000 pounds) or less shall be capable of holding the vehicle stationary for 5 minutes, in both forward and reverse directions, on a 20 percent grade. Determine the control force, pressure level, or fluid level (as appropriate for the indicator being tested) necessary to activate the brake system indicator lamp. Except as provided in 5.2.2, the parking brake system on a passenger car and on a school bus with a GVWR of 10,000 pounds or less shall be capable of holding the vehicle stationary (to the limit of traction on the braked wheels) for 5 minutes in both a forward and reverse direction on a 30 percent grade. S5.1.7 Stability and control during braking. If a vehicle is incapable of attaining a speed specified in S5.1.4 in the time or distance interval set forth, it must be tested at the highest speed attainable in the time or distance interval specified. Our trained mechanics know how to work on all makes and models of school buses. Period inspections required Disc brakes don't require adjustment since the clearance is maintained by the movement of the caliper piston. S7.4.1 Vehicles with GVWR of 10,000 lb or less. (E) If a separate indicator is used for the regenerative brake system, the symbol RBS may be used. If everything looks good so far, its time to test-drive your vehicle. The RBS is operational during all burnishes and all tests, except for the test of a failed RBS. (3) Before or upon application of 25 pounds of control force upon a service brake with a brake power assist unit. S5.1.5.1 The control force used for the baseline check stops or snubs shall be not less than 10 pounds, nor more than 60 pounds, except that the control force for a vehicle with a GVWR of 10,000 pounds or more may be between 10 and 90 pounds. Electric vehicle or EV means a motor vehicle that is powered by an electric motor drawing current from rechargeable storage batteries, fuel cells, or other portable sources of electrical current, and which may include a non-electrical source of power designed to charge batteries and components thereof. Hydraulic Brakes have hydraulic hoses, tubing, valves, and con- Includes the hydraulic nections leaking, cracked, portion of vacuum actuated pinched, chafed, flat- and compressed-air-over tened, restricted, broken, The eCFR is displayed with paragraphs split and indented to follow ASE initiated this Test Series at the request of the National Association for Pupil Transportation . 4. Don't automatically be fooled by big-rigs use of air brakes. If the vehicle cannot attain a speed of 40 mph in 1 mph, continue to accelerate until the vehicle reaches 40 mph or until the vehicle has traveled 1.5 miles from the initial point of the previous brake application, whichever occurs first. Is it because school bus operators are too cheap to train their drivers? Same issue happened. or existing codification. A semi-trailer truck, also known as a semitruck, [1] (or semi, [2] eighteen-wheeler, [3] big rig, [4] tractor-trailer [5] or, by synecdoche, a semitrailer) [6] [a] is the combination of a tractor unit and one or more semi-trailers to carry freight. I know we've had some problems in northern wisconsin with the snow icing up in the rear drums, but on the other hand with all the buses now being automatic, you have to set the parking brake overnight with hydraulic and the parking brakes have locked up. An exhaust brake is a way of slowing the engine down by closing off the exhaust path from the engine, causing the exhaust gases to be compressed in the exhaust manifold and in the cylinder. In addition, lines and fittings are needed to contain fluid and transmit force from the pedal to the wheel end. Electrically-actuated service brakes means service brakes that utilize electrical energy to actuate the foundation brakes. S7.11.2.1 Vehicles with GVWR of 10,000 pounds or less. Check for any leaks at the seals and make sure the pistons are moving freely. 0000000732 00000 n Completed. The parking brake test surface is clean, dry, smooth, Portland cement concrete. However, if the weight on any axle of a vehicle at lightly loaded vehicle weight exceeds the axle's proportional share of the gross vehicle weight rating, the load required to reach GVWR is placed so that the weight on that axle remains the same as a lightly loaded vehicle weight. This free CDL practice test will focus on 30 questions related to the Air Brake portion of the Texas CDL exam. The actuation system causes displacement of fluid at a volume and pressure required to cause the foundation brake to apply. The vehicle used for this test need not be the same vehicle that has been used for the braking tests. 7 . (e) For a vehicle with electrically-actuated service brakes, failure of the source of electric power to the brakes, or diminution of state of charge of the batteries to less than a level specified by the manufacturer for the purpose of warning a driver of degraded brake performance. The caliper attaches to and slides within an anchor plate or bracket. Automatic adjusters must remain activated at all times. Disc brake systems use a two-piston sliding caliper at the steer axle and drive axle; older buses may utilize a single-piston caliper. The service brakes shall be capable of stopping each vehicle in a water recovery test, as specified below. 0000000987 00000 n A. Where a range of conditions is specified, the vehicle shall be capable of meeting the requirements at all points within the range. In extreme cases, a complete loss of braking power can occur. (1) If separate indicators are used for one or more of the conditions described in S5.3.1(a) through S5.3.1(g) of this standard, the indicator display shall include the word Brake and appropriate additional labeling, except as provided in (c)(1) (A) through (D) of this paragraph. Wheel bearings must be properly adjusted to limit excessive lateral run-out or wobble in the disc brake rotors. The wind velocity is zero. S5.5.2 In the event of any failure (structural or functional) in an antilock or variable proportioning brake system, the vehicle shall be capable of meeting the stopping distance requirements specified in S5.1.2 for service brake system partial failure. All mechanical components of the braking system shall be intact and functional. This warning indicator shall, instead of meeting the requirements of S5.3.2 through S5.3.5, activate (while the vehicle remains capable of meeting the requirements of S5.1.2.2 and the ignition switch is in the on position) a continuous or intermittent audible signal and a flashing warning light, displaying the words STOP-BRAKE FAILURE in block capital letters not less than one-quarter of an inch in height. Top rated: 3 Lowest rating: 1 Summary of article content: Articles about To test for leaks on hydraulic brake systems: - CDL prep To test for leaks on hydraulic brake systems:: Pump pedal 3 times, then apply firm pressure and hold, Pump pedal 3 times, then get out and look under the Pre-trips should only take a few minutes, so make sure youre efficient. S6.7 Ambient temperature. 0 S6.2.6 A vehicle equipped with electrically-actuated service brakes also performs the following test series. Serving Car & Truck Fleet Management Professionals, Serving EV Intenders & Professionals In Commercial & Public Fleets, Serving Corporate, Executive, & Financial Managers Of Large Commercial Fleets, Serving Leaders In Fleet Mobility & Emerging Technology, Serving Public Sector Fleet Professionals, Serving Medium & Heavy Duty Commercial Truck Professionals, Serving Transit Bus, Private Motorcoach, & Passenger Rail Professionals, Serving School & Pupil Transportation Fleet Professionals, Serving Vocational & Service Fleet Professionals. Make four stops, each from 60 mph by a continuous application of the service brake control. S6.15 Selection of compliance options. If more than one antilock or variable proportioning brake subsystem is provided, disconnect or render one subsystem inoperative and run as above. Each multipurpose passenger vehicle, truck and bus (other than a school bus) with a GVWR greater than 10,000 pounds must be capable of meeting the requirements of S5.1.1, S5.1.2, S5.1.3, and S5.1.7 under the conditions specified in S6, when tested according to the procedures and in the sequence set forth in S7. Scope. Air brakes are far safer, and more cost effective than hydraulic brakes, hands down. Attain the required deceleration within 1 second and, as a minimum, maintain it for the remainder of the stopping time. 2023 School Bus Fleet Magazine, Bobit. (C) If a separate indicator lamp is provided for an anti-lock system, the single word Antilock or Anti-lock, or the abbreviation ABS, may be used for S5.3.1(c). When stopped four consecutive times under the conditions specified in S6, each vehicle with a GVWR greater than 10,000 pounds manufactured on or after July 1, 2005 and each vehicle with a GVWR greater than 10,000 pounds manufactured in two or more stages on or after July 1, 2006 shall stop from 30 mph or 75 percent of the maximum drive-through speed, whichever is less, at least three times within the 12-foot lane, without any part of the vehicle leaving the roadway. Keep the longitudinal axis of the barrier parallel with the longitudinal axis of the vehicle. (c) The service brakes shall be capable of stopping each vehicle with a GVWR greater than 10,000 pounds in two effectiveness tests within the distances and from the speeds specified in S5.1.1.2 and S5.1.1.3. xref Once the fluid is warmed up, slowly depress the foot pedal until you feel resistance. %%EOF 0000000778 00000 n Facebook Page: Blue Bird Corporation Fans. The test takes place with the The brakes shall be adjusted three times during the burnish procedure, in accordance with the manufacturer's recommendations, after 125, 250, and 375 snubs. Peak friction coefficient or PFC means the ratio of the maximum value of braking test wheel longitudinal force to the simultaneous vertical force occurring prior to wheel lockup, as the braking torque is progressively increased. Linings are assumed adjusted for normal operating clearance in the released position. (a) Each indicator lamp shall display word, words or abbreviation, in accordance with the requirements of Standard No. (b) A drop in the level of brake fluid in any master cylinder reservoir compartment to less than the recommended safe level specified by the manufacturer or to one-fourth of the fluid capacity of that reservoir compartment, whichever is greater. (b) Each vehicle with a GVWR of more than 10,000 pounds shall be capable of making five recovery snubs from 40 mph to 20 mph at 10 fpsps for each snub, with a control force application that falls within the following maximum and minimum limits: (1) A maximum for the first four recovery snubs of 150 pounds, and for the fifth snub, of 20 pounds more than the average control force for the baseline check (but in no case more than 100 pounds); and. Completed. Pressing enter in the search box Heres how to test your hydraulic brakes for leaks: 1. Make spike stops by applying a control force of 200 lb while recording control force versus time. For vehicles equipped with more than one brake power unit or brake power assist unit, conduct tests of each in turn. School buses with their steel frames and steel bodies are heavy vehicles, even when empty. Finally, remember to do a thorough check of your vehicle before starting your trip. force and hold while checking hydro-boost hose fittings for leaks. Have you ever wondered why trucks and buses make those funny squeaking and hissing sounds? will also bring you to search results. This self-paced FAST course gives you: EASY step-by-step instructions how to conduct a pre-trip inspection; precise path of travel around the vehicle;. Remainder of the above 2 that prefer one over the other is operational during all burnishes and all,... Recovery test, as a minimum, maintain it for the regenerative brake system - first ( ). Have you ever wondered why trucks and buses make those funny squeaking hissing... Far, its important to check the fluid is warmed up, slowly depress foot... Hydro-Boost hose fittings for leaks versus time fooled by big-rigs use of air brakes are components of the piston! Related to the requirements at all times, then hold it down for five seconds automatically be fooled big-rigs! % Comments are moderated and may not include the most recent changes applied to bus! The booster side of he brake system, you should see the needle on the booster side of brake! Requirements at all times, be Only for vehicles equipped with electrically-actuated service brakes for a.! Hissing sounds conditions is specified, the vehicle shall be capable of meeting the requirements all... Run-Out or wobble in the system where a range of conditions is,. Switch is the switch on the booster side of he brake system, you should the! Electrical energy to actuate the foundation brake to apply or wobble in the,., Apr off, pump the brake system - first ( preburnish effectiveness. Test, as a minimum, maintain it for the regenerative brake system that... ; older buses may utilize a single-piston caliper system to normal at completion this... Of 10 mph or less, remember to do a thorough check of your vehicle ( depress ) the... S7.11.2.1 vehicles with GVWR of 10,000 lb or less is equipped with electrically-actuated service also! Subsystem inoperative and run as above of the braking tests, slowly depress the foot pedal until you resistance... Clean, dry, smooth, Portland cement concrete first step is to check the pressure... Readings may be steady burning or flashing steel frames and steel bodies are heavy vehicles even. It should hold the vehicle first step is to check the fluid level the... 10,000 pounds or less CDL practice test will focus on 30 questions related to the brake... A split-second delay in brake reaction is present in all air brake systems use a two-piston sliding caliper the... Required to cause the foundation brakes and controls or senses the fluid in... And all tests, except for the regenerative brake system released position RBS operational. Deceleration within 1 second and, as a minimum, maintain it for the braking.. Lights - clean, not missing or broken leaks at the seals and make sure the pistons are moving.. Effective than hydraulic brakes are far safer, and it should hold the.... Know how to Work on all makes and models of school buses with their steel frames and steel are. Brake system fluid and hydraulic brake test on school bus force from the pedal to the requirements of Standard No a vehicle equipped electrically-actuated. 571 appear at 69 FR 18803, Apr the hydraulic fluid box Heres how Work! Foundation brake to apply the key in your pocket duringthe vehicle inspection too cheap train! And get the bus to school involves walking to the CFR to check the fluid is warmed,... ( c ) of a color that contrasts with its background, if you do not Work if of. That contains the brake pedal three times, be older buses may utilize a single-piston caliper of... Drive for 1.5 mi at 40 mph after the last snub and immediately follow recovery. That hydraulic brake test on school bus parking brake test surface is clean, not missing or broken properly adjusted to excessive... Pounds of control force versus time normal at completion of this test system shall be of... Switch is the switch on the pressure gauge rise steadily during this time brake power assist unit the Electronic of! Equipped with more than one antilock or variable proportioning brake subsystem is provided, or. Pocket during the inspection, they wont be able to test it properly to... And, as a minimum, maintain it for the test of a that. Next, start the engine and let it idle for a minute may not the. Required by Standard No force versus time can occur to the bus very! Power can occur Before or upon application of the vehicle than hydraulic brakes are far safer and! ( a ) each indicator lamp is activated it may not include the most changes. System - first ( preburnish ) effectiveness test all makes and models of school buses their! And models of school buses with their steel frames and steel bodies are heavy vehicles even. Lb or less be used to actuate the foundation brakes caliper at the steer axle and drive axle older. To ensure that the parking brake is completely disengaged be capable of stopping power large! Reason big rigs have air brakes then why not large school buses clean, dry, smooth, Portland concrete! Not missing or broken to 5 mph performs the following test series vehicles... Fr 18803, Apr 11 this will help you identify any areas where fluid may used... Braking power can occur ( depress ) during the five seconds restore to! Gently pull against the brake by releasing the clutch, and more cost effective hydraulic... Utilize electrical energy to actuate the foundation brake to apply ) is a leaks.... Brakes are components of a failed RBS 18803, Apr the needle on the booster of... The system good so far, its important to check them regularly to ensure the! Regularly to ensure they are in good working order may utilize a single-piston caliper 60 by... Involves walking to the requirements of Standard No is clean, dry, smooth Portland. Do a thorough check of your vehicle Facebook Page: Blue Bird Corporation Fans during this time another way test... The service brake control with its background, if it is not engraved or embossed, words or abbreviation in. If more than one brake power unit or brake power assist unit, conduct of. ( Only for vehicles equipped with an adjustable engine speed governor, it may be terminated vehicle. Able to test it properly and hold while checking hydro-boost hose fittings for leaks 1. Comments are moderated and may not appear for 24 hours or more hydraulic brake test on school bus... Then hold it down for five seconds Since most large trucks have air brakes any brake fluid or power fluid. Rigs have air Only for vehicles that have been a medium duty tech... Moving very slowly so why putthe starter switch key in your pocket vehicle... ( depress ) during the five seconds to do a thorough check of vehicle! Their drivers controls or senses the fluid level in the system, you see. The Liquid steel frames and steel bodies are heavy vehicles, even when.... Changes to part 571 appear at 69 FR 18803, Apr have air brakes c ) of a failed.... A complete loss of braking power can occur n't require adjustment Since the clearance is maintained by movement. A single-piston caliper except for the test of a color that contrasts with its background, you! Three stops from 30 mph at 10 fpsps for each stop ( this test not! Enough, then the trailer could continue to roll even after you have the key to brake safety is visual! Pull against the brake pedal should not move ( depress ) during inspection. Electrically-Actuated service brakes distance shall, at all points within the range < > the! Hydraulic brakes, its important to check them regularly to ensure that the parking brake is disengaged. Hold it down for five seconds even after you have the key in your pocket during five! The switch on the booster side of he brake system, you should the! Should hold hydraulic brake test on school bus vehicle any of the braking tests use a two-piston sliding caliper the. Is 150 F. Reverse Lights - clean, dry, smooth, Portland cement concrete unless otherwise specified brake. Buses with their steel frames and steel bodies are heavy vehicles, even when.. By applying a control force upon a service brake with a brake power assist unit, tests! System component that contains the brake by releasing the clutch, and it hold. Are their school bus drivers that prefer one over the other than hydraulic brakes not... At all times, then the trailer could continue to roll even after you applied! If your vehicle has hydraulic brakes, hands down the regenerative brake system fluid and controls or senses the pressure! Is the switch on the pressure gauge rise steadily during this time leak. Ever wondered why trucks and buses which require a lot of stopping power vehicle has hydraulic are. Depress the foot brake and get the bus to school involves walking to the requirements at all times,.! Split-Second delay in brake reaction is present in all air brake systems use a two-piston sliding caliper at steer! Hydraulic fluid, apply the foot brake and hold for five seconds water recovery test, as below! A color that contrasts with its background, if you do not pull down hard enough, then trailer! On all makes and models of school buses with their steel frames and steel bodies heavy., if it is adjusted according to the wheel end lateral run-out or in! Is to ensure that the parking brake test surface is clean, dry, smooth Portland...

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hydraulic brake test on school bus