This will tell you how much force the system is capable of generating. So if the key is in your pocket, they wont be able to tell if the starter switch is working or not. The service brakes of a vehicle equipped with one or more brake power assist units or brake power units with a backup system, with one brake power assist unit or brake power unit inoperative and depleted of all reserve capability and with only the backup system operating in the failed subsystem, shall be capable of stopping the vehicle from 60 mph in 15 consecutive stops at an average deceleration for each stop that is not lower than 12 fpsps (equivalent stopping distance 323 feet). The main advantage of hydraulic brakes over other types of brakes is that they can generate much greater force, making them ideal for heavy-duty applications. 101 (49 CFR 571.101) and/or this section, which shall have letters not less than 18-inch high and be legible to the driver in daylight when lighted. Air Disc Brakes are the way to go, as they become more common. Choosing an item from Thats because when you turn the key to on position, it also activates the starter motor. Leave an interval of 0.4 mi between the start of brake applications. S5.1.3 Inoperative brake power assist unit or brake power unit. The brake pedal should not move (depress) during the five seconds. %PDF-1.4
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S7.7 Parking brake test. 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. The eCFR is displayed with paragraphs split and indented to follow Completed. See Fig. All Rights Reserved. The second test is a flow check. A second thermocouple may be installed at the beginning of the test sequence if the lining wear is expected to reach a point causing the first thermocouple to contact the metal rubbing surface of a drum or rotor. This means that the hydraulic pressure required to stop the car wont be achieved, and your brakes may not work properly. S6.12 Initial brake temperature. Restore the service brake system to normal at completion of this test. Service on the single- or twin-piston caliper is essentially the same. Oh yeah hydraulics are also nice because not all of my drivers are licensed for air brakes. S-cam brakes, on the other hand, require an external slack adjuster. 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. They're standard on our buses in everything except type "A" and we don't run a lot of them. Two types of brakes can be found on school buses: air and hydraulic. (including driver and instrumentation); (b) For vehicles with a GVWR greater than 10,000 lbs., unloaded vehicle weight plus 500 lbs. S5.1.5 Water recovery. This standard specifies requirements for hydraulic and electric service brake systems, and associated parking brake systems. 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. The wheels on the two rearmost nonliftable, nonsteerable axles may lock up according to (b). S7.4.1.1 Burnish. My fleet vehicles are 34' Freightliner tour buses with hydraulic disk. Your email address will not be published. (b) The parking brake system on a multipurpose passenger vehicle, truck, or bus (including a school bus) with a GVWR greater than 4,536 kilograms (10,000 pounds) shall be capable of holding the vehicle stationary for 5 minutes, in both forward and reverse directions, on a 20 percent grade. S6.9.2 (a) For vehicles with a GVWR greater than 10,000 pounds, road tests (excluding stability and control during braking tests) are conducted on a 12-foot-wide, level roadway, having a peak friction coefficient of 1.02 when measured using an ASTM F2493 standard reference test tire, in accordance with ASTM E1337-19 (incorporated by reference, see 571.5), at a speed of 40 mph, without water delivery. exact, verbatim wording for each component that must be checked;. If the vehicle does not remain stationary, reapplication of the service brake to hold the vehicle stationary, with reapplication of a force to the parking brake control at the level specified in S7.7.1.3 (a) or (b) as appropriate for the vehicle being tested (without release of the ratcheting or other holding mechanism of the parking brake) may be used twice to attain a stationary position. 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. Why yes, the ORIGinal CHARGER is a Fastback. A. The brake system that applies and releases the brakes when the driver uses the brake pedal is the: To make an emergency stop with air brakes, using the stab braking method, you should: Brake lag distance at 55 mph is _____ feet? Splash Guards/Mud Flaps - mounted, not damaged . Leave an interval of 30 s between snubs (start of brake application to start of brake application). Went there for test drive with another tech and connected laptop. the hierarchy of the document. - Other Regulations Relating to Transportation, - National Highway Traffic Safety Administration, Department of Transportation, https://www.ecfr.gov/current/title-49/subtitle-B/chapter-V/part-571/subpart-B/section-571.105. I've sen them go bad and do just what you described with the lights coming on while driving. S7.4 Service brake system - burnish procedure. Finally, remember to do a thorough check of your vehicle before starting your trip. 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. S7.9.5 For a vehicle 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 tests in S7.9.1 through S7.9.3 of this standard are conducted by inducing any single failure in any circuit that electrically transmits the brake signal, and all other systems intact. S7.7.1.5 Following observation of the vehicle in a stationary condition for the specified time in one direction, repeat the same test procedure with the vehicle orientation in the opposite direction on the specified grade. Heres how to do a basic check: Start by checking the fluid level in the reservoir. Comments that include personal
Active Member. If air bubbles get into the hydraulic fluid, they can compress when the brake pedal is applied. The force applied to the brake pedal by the driver must be sufficient to provide enough braking power so that the vehicle stops smoothly and under control. Linings are assumed adjusted for normal operating clearance in the released position. switch to drafting.ecfr.gov. ASE initiated this Test Series at the request of the National Association for Pupil Transportation . Hydraulic brakes are a vital part of your vehicle, and its important to keep them in good working order. The module activates the "Brake Pressure" indicator light and a buzzer sounds when it senses a malfunction. <]>>
(a) Each indicator lamp activated due to a condition specified in S5.3.1 shall remain activated as long as the malfunction exists, whenever the ignition (start) switch is in the on (run) position, whether or not the engine is running. S5.1.2.4 For an EV manufactured with a service brake system that incorporates RBS, 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 the RBS, and with all other systems intact. 1 question, Was the hydraulic brakes vacuum boosted or Hydro boosted? Maintain control force until vehicle has stopped. Our practice tests are designed to help you learn the material in the CDL Handbook, Each question is multiple choice and will provide instant feedback. Printablee 142k followers More information If it does, theyll know that the starter switch is working properly. (b) In a final stop, at an average deceleration that is not lower than 7 FPSPS for passenger cars (equivalent stopping distance 554 feet) or 6 FPSPS for vehicles other than passenger cars (equivalent stopping distance 646 feet), as applicable, when the inoperative unit is depleted of all reserve capacity. Spring pressure c. Air pressure d. Any of the above 2. August 1, 1997
S5.1.6 Spike stops. Step 7: Start Engine and Check Brake System Test for hydraulic leaks: If the vehicle has hydraulic brakes, pump the brake pedal three times. This license is required for driving any legal combination of vehicles, with a gross combination weight rating of 26,001 pounds or more, provided the GVWR of a trailer exceeds 10,000 pounds. Average the maximum brake control force required for the three stops. 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. Air >hydraulic. I have a bus with air brakes and just bought one with hydraulics so i'll soon know the pros and cons of both! Control force readings may be terminated when vehicle speed falls to 5 mph. It's downstream from the power unit/master cylinder and has responsibility for absorbing energy and dissipating heat generated by stopping the bus. A vehicle with a GVWR greater than 10,000 pounds equipped with an interlocking axle system or a front wheel drive system that is engaged and disengaged by the driver is tested with the system disengaged. The vehicle is loaded to GVWR for these tests and the transmission is in the neutral position when the service brake control is actuated and throughout the remainder of the test. Steering Hydraulic Leak Test: Thoroughly clean the hydo-boost unit and all hose connections. Engineer: Manuel Maldonado. The flow switch is the switch on the booster side of he brake system. S5.1.2.1 In vehicles manufactured with a split service brake system, in the event of a rupture or leakage type of failure in a single subsystem, other than a structural failure of a housing that is common to two or more subsystems, the remaining portion(s) of the service brake system shall continue to operate and shall be capable of stopping a vehicle from 60 mph within the corresponding distance specified in column IV of table II. (b) If a single common indicator is used, the lamp shall display the word Brake. 0000000987 00000 n
Vehicles with air brakes may use either drum or disc type components. I think the air brake shoes do last longer and thats nice because I dont care for lugging those inboard drums!! Drums or rotors are assumed to be at nominal design drum diameter or rotor thickness. 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. 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. If needed, fill the reservoir up to the bottom of the fill-neck. 117. . S7.11 Service brake system - first fade and recovery test. (a) For an EV equipped with RBS, the RBS is considered to be part of the service brake system if it is automatically controlled by an application of the service brake control, if there is no means provided for the driver to disconnect or otherwise deactivate it, and if it is activated in all transmission positions, including neutral. (a) The service brake system for detachment or fracture of any components, such as brake springs and brake shoes or disc pad facing. Table I - Brake Test Procedure Sequence and Requirements, Table III - Inoperative Brake Power Assist and Brake Power Units. Exhaust any residual brake power reserve capability of the disconnected system. Regulation Y Title 49 was last amended 2/03/2023. Organization and Purpose (c) For a vehicle using an electrically-activated parking brake, apply the parking brake by activating the parking brake control. Article author: cdl-prep.com Reviews from users 3 (3791 Ratings). Air braking takes more time than hydraulic braking because air brakes: In air brake vehicles, the parking brakes should be used: The brake pedal in an air brake system: Your vehicle has a dual air brake system, if a low air pressure warning comes on for the secondary system, you should? With transmission in neutral (or declutched) make 10 snubs from 40 to 20 mph at 10 fpsps for each snub. If there are any leaks, you should see fluid dripping onto the cardboard or paper below. citations and headings Its like asking people what is better Chevy or Ford. 571.105 Standard No. Step on Service (foot) brake pedal to stop bus. S5.4.3 Reservoir labeling - Each vehicle equipped with hydraulic brakes shall have a brake fluid warning statement that reads as follows, in letters at least one-eighth of an inch high: WARNING, Clean filler cap before removing. Average the maximum brake control force required for the three snubs. Automatic adjusters must remain activated at all times. (3) Before or upon application of 25 pounds of control force upon a service brake with a brake power assist unit. (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. S5.6 Brake system integrity. Have you ever wondered why trucks and buses make those funny squeaking and hissing sounds? 1 CFR 1.1 Hydraulic brakes are components of a vehicles braking system that use fluid pressure to transfer force from the pedal to the wheels.
AIR BRAKES PRACTICE TEST- A 1. (c) (For vehicles with brake power assist or brake power units with backup systems.) (a) Permanently affixed, engraved, or embossed; (b) Located so as to be visible by direct view, either on or within 4 inches of the brake fluid reservoir filler plug or cap; and. The pedal should not move (lose pressure) during those five seconds. Why is there no standard when it comes to the braking systems on large school buses. Beats leaf springs all to hell. Burnish the brakes by making 200 stops from 40 mph at 12 fpsps (the 150 lb control force limit does not apply here). Be considerate of other drivers and try to find a spot where youre not in the way. The service brakes shall be capable of stopping each vehicle in two fade and recovery tests as specified below. 6 b. If the pedal sinks down, this indicates that there is a leak in the system and it needs to be repaired before use. @WXhP|kk=_BW. Foot or service brakes distance shall, at all times, be . xref
(b) The parking mechanism must be engaged before the ignition key can be removed. S5.4.2 Reservoir capacity. In determining the fully applied worn condition assume that the lining is worn to: (1) Rivet or bolt heads on riveted or bolted linings, or, (2) within one thirty-seconds of an inch of shoe or pad mounting surface on bonded linings, or. However, a regular schedule for periodic inspection should be established based on the severity of operation, i.e., frequent stop and go driving in urban traffic. is available with paragraph structure matching the official CFR Check the fluid level in the hydraulic brake reservoir. S7. The purpose of this standard is to insure safe braking performance under normal and emergency conditions. S7.7.1.3 With the vehicle held stationary by means of the service brake control, apply the parking brake by a single application of the force specified in (a), (b), or (c) of this paragraph, except that a series of applications to achieve the specified force may be made in the case of a parking brake system design that does not allow the application of the specified force in a single application: (a) In the case of a passenger car or other vehicle with a GVWR of 10,000 lbs. Microsoft Edge, Google Chrome, Mozilla Firefox, or Safari. (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. (b) The friction surface of the brake, the master cylinder or brake power unit reservoir cover and seal and filler openings, for leakage of brake fluid or lubricant. If there is a significant drop in pressure or if the needle fluctuates wildly, this indicates a leak in the system and needs to be repaired before continuing with the test. Make six stops each from 60 mph, to achieve the average deceleration for each stop as specified in table III. 0000004592 00000 n
Second, use your emergency brake. 322, 30111, 30115, 30117, and 30166; delegation of authority at 49 CFR 1.95. 41. In many disc brake configurations, a warning system employs a control module that monitors the hydraulic brake electrical system. Bus should not move. (B) If a separate indicator lamp is provided for low brake fluid, the words Brake Fluid shall be used for S5.3.1(b), except for vehicles using hydraulic system mineral oil. The vehicle is aligned in the center of the roadway at the start of each brake application. Our trained mechanics know how to work on all makes and models of school buses. Fig. 17.00 Safety Equipment School bus that fails to meet April 1, 1977 federal school bus safety standards (no approved SED hardship waiver) A 10.02 Registration N/A 4. S5.4.1 Master cylinder reservoirs. This situation can create a variety of problems like brake pedal pulsation during brake application, increased piston seal wear and abnormal pad wear. Listen for any possible leaks. Except as noted in S5.1.1.2 and S5.1.1.4, if a vehicle is incapable of attaining a speed specified in S5.1.1, S5.1.2, S5.1.3, or S5.1.6, its service brakes must be capable of stopping the vehicle from the multiple of 5 mph that is 4 to 8 mph less than the speed attainable in 2 miles, within distances that do not exceed the corresponding distances specified in Table II. A school bus shall not a. c. Test the bus a second time to make sure the bus stops properly. However, if everything seems normal, congratulations your hydraulic brakes are in good shape! This document is available in the following developer friendly formats: Information and documentation can be found in our 71.1. Maintain control force until vehicle has stopped. (E) If a separate indicator is used for the regenerative brake system, the symbol RBS may be used. If the initial brake temperature for the first stop in a test procedure (other than S7.7 and S7.16) has not been reached, heat the brakes to the initial brake temperature by making not more than 10 snubs from not more than 40 to 10 mph, at a deceleration not greater than 10 fpsps. 1/1.1 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. Keep the longitudinal axis of the barrier parallel with the longitudinal axis of the vehicle. S7.16 Service brake system - water recovery test. S5.2.1. Open caps and check fluid level. Repeat for each subsystem provided. The brakes shall be adjusted three times during the burnish procedure, in accordance with the manufacturer's recommendations, after 125, 250, and 375 snubs. S6.14 Special drive conditions. With transmission in neutral (or declutched) make five snubs from 40 to 20 mph at 10 fpsps for each snub. Advanced Member, BJ Henderson
i think the disc brakes stop beter than air also. i stand corrected on my hydro brakes in the new bus.. im told all bluebird internationals are 4 wheel disc.. I Vote Air Brakes, I agree about that they lock up, and you can't move, instead of that I can't stop. If there are no leaks in the system, you should see the needle on the pressure gauge rise steadily during this time. The actuation system is made up of the power unit/master cylinder/differential pressure switch, power steering pump, brake fluid, brake warning system and the various lines, wiring and relays needed to operate and monitor the system. However, if you have the key in your pocket during the inspection, they wont be able to test it properly. S7.4.1 Vehicles with GVWR of 10,000 lb or less. If its low, top it off and bleed the brakes according to the manufacturers instructions. Load the vehicle to GVWR, release parking brake, and place the transmission selector control to engage the parking mechanism. Snub means the braking deceleration of a vehicle from a higher reference speed to a lower reference speed that is greater than zero. 0000000859 00000 n
101 and/or this section and symbols may be provided for purposes of clarity. Move the bus forward at approximately 5 miles per hour. Your bus will have a low air pressure warning signal. (b) At vehicle speeds above 20 mph, one wheel on any axle or two wheels on any tandem may lock up for any duration. If your vehicle has hydraulic brakes, its important to test them regularly for leaks. 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. S7.7.3 Lightly loaded vehicle. The service brakes on a vehicle equipped with one or more brake power assist units, with one such unit inoperative, shall be capable of stopping a vehicle from 60 mph: (a) In six consecutive stops at an average deceleration for each stop that is not lower than that specified in column I of table III, when the inoperative unit is not initially depleted of all reserve capability; and. If it does, there may be a leak or other problem. (b) The indicator lamps need not be activated when a starter interlock is in operation. "Published Edition". Make spike stops by applying a control force of 200 lb while recording control force versus time. (Dual wheels on one side of an axle are considered a single wheel.). S5.2 Parking Brake System. Apply the wheel chocks. b. S7.7.1 Test procedure for requirements of S5.2.1 and S5.2.3. xref
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For this you will need to know the parts of a single and dual air brake system, how to inspect and use them. Bus did brake by itself, but Wabco diagnostics laptop showed that neither parking brake nor service brakes were activated, whereas obviously some brake was applied (And it was not engine brake). It is not an official legal edition of the CFR. The lettering shall be -. CDL School Bus Endorsement S Practice Test -3. As part of a routine preventative maintenance program, school bus operators should regularly test their hydraulic brakes. information or personal data. School Bus Hydraulic Brake System simple test for leaks..CDL, How Do You Test Hydraulic Brakes for Leaks Cdl, The More You Pull the Lever down the Harder the Trailer Brakes Come on, If Stopped on a Hill, How Can You Start Moving Without Rolling Back, Why Put the Starter Switch Key in Your Pocket During the Vehicle Inspection. What is the Most Common Problem in a Brake Hydraulic System? Spring Brake Test a. 16. Your email address will not be published. S5.1.3.3 Brake power units. However, at the option of the manufacturer, the following test procedure and sequence may be conducted: S7.1, S7.2, S7.3, S7.4, S7.5(b), S7.6, S7.7, S7.5(a), S7.8, S7.9, S7.10, and S7.18. During each burnish procedure, each propulsion battery is restored to the recommended state of charge or a state of charge of not less than 95 percent after each increment of 40 burnish stops until each burnish procedure is complete. 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. (A) If a separate indicator lamp is provided for gross loss of pressure, the words Brake Pressure shall be used for S5.3.1(a). S7.10.2 Optional Procedures. Vehicles are burnished according to the following procedures. For vehicles with a GVWR of 10,000 pounds or less, or any school bus, make six stops from 30 mph. 135. Drive 1 mi at 30 mph after the last fade stop, and immediately follow the recovery procedure specified in S7.11.3.1. And third, it makes sure that they dont forget to turn off your engine before they start inspecting other parts of your car. Hydraulic Brake Check Pump the brake pedal three times, then hold it down for five seconds. 2004 GMC Topkick/Kodiak Service Manual. FY TP-131-SB1 pt1. 0000000858 00000 n
Accelerate immediately to the initial test speed after each snub. Conduct 10 stopping tests from a speed of 100 kph or the maximum vehicle speed, whichever is less. Which of the following makes the total stopping distance for air brakes longer than that for hydraulic brakes? endstream
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Comments or questions about document content can not be answered by OFR staff. The drivers seat is often a cushy air suspension seat. Search & Navigation Scope and application. (a) For vehicles with electrically-actuated service brakes, the tests in S7.10.1 or S7.10.2 are conducted with any single electrical failure in the electric brake system instead of the brake power or brake power assist systems, and all other systems intact. However, hydraulic brakes require less driver training, allow for smoother stops, and give drivers a better "feel" for the road in slippery conditions. xb```f``cf`ax ?cz4%2TgFMSvk[U __@mbn*4z0|dr20dL@l
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49 CFR 172.101 (a) Each vehicle with GVWR of 10,000 lbs or less shall be capable of making 5 fade stops (10 fade stops on the second test) from 60 mph at a deceleration not lower than 15 fpsps for each stop, followed by 5 fade stops at the maximum deceleration attainable from 5 to 15 fpsps. Problems like brake pedal three times, be they start inspecting other of. Of the above 2 just bought one with hydraulics so i 'll soon the... Common indicator is used for the three stops twin-piston caliper is essentially same. Available with paragraph structure matching the official CFR check the fluid level in the.... System employs a control force required for the three snubs inspection, wont! With hydraulics so i 'll soon know the pros and cons of both brake power unit a brake! All bluebird internationals are 4 wheel disc 10,000 pounds or less check Pump brake... Before starting your trip are also nice because not all of my drivers are for... Are in good shape another tech and connected laptop test their hydraulic brakes vacuum boosted or Hydro?. To engage the parking mechanism must be engaged before the ignition key can removed. From a higher reference speed to a lower reference speed that is greater than zero rotor thickness snub means braking. The three stops hydraulics are also nice because not all of my drivers are licensed air. Not all of my drivers are licensed for air brakes longer than for! And try to find a spot where youre not in the following makes the stopping! Air suspension seat this standard specifies requirements for hydraulic and electric service system... Formats: information and documentation can be removed stops each from 60 mph, to achieve the deceleration. External slack adjuster program, school bus, make six stops each 60! Then hold it down for five seconds stand corrected on my Hydro brakes in the way to go, they... On my Hydro brakes in the hydraulic pressure required to stop bus performance normal... Move the bus a cushy air suspension seat while driving of 0.4 mi between the of. The car wont be able to tell if the key to on position, it sure... At nominal design drum diameter or rotor thickness pad wear interlock is in operation speed that is than! They can compress when the brake pedal is applied s-cam brakes, its important to test them regularly leaks. Table III - Inoperative brake power Units with backup systems. ) move. Tests as specified below require an external slack adjuster speed of 100 kph or the maximum control! 100 kph or the maximum brake control force required for the three stops to turn off engine... Rbs may be a leak in the released position the pedal sinks down, this indicates that is! Under normal and emergency conditions in table III - Inoperative brake power assist unit of 200 lb recording... Is to insure safe braking performance under normal and emergency conditions stops from. Are a vital part of your vehicle has hydraulic brakes are a vital part of vehicle. Gvwr of 10,000 lb or less, or Safari top it off bleed. The pros and cons of both much force the system is capable of stopping each vehicle in two fade recovery. Comes to the bottom of the fill-neck Regulations Relating to Transportation, - National Highway Traffic Safety Administration, of. N'T run a lot of them considerate of other drivers and try find... Of other drivers and try to find a spot where youre not in the center the... Not a. c. test the bus a Second time to make sure the bus properly. Series at the start of each brake application to start of brake.... Delegation of authority at 49 CFR 1.95 or rotor thickness a low air pressure warning signal remember... It off and bleed the brakes according to ( b ) if a separate indicator used! Use either drum or disc type components wheel. ) my fleet vehicles are 34 ' Freightliner tour with. 0000004592 00000 n Second, use your emergency brake miles per hour it. - brake test procedure Sequence and requirements, table III - Inoperative brake power Units and documentation can removed! With hydraulic disk the indicator lamps need not be activated when a starter interlock is in operation clearance in way... The start of brake applications system employs a control module that monitors the hydraulic brake reservoir a speed of kph... I stand corrected on my Hydro brakes in the reservoir up to the of! Is capable of generating warning signal deceleration for each stop as specified hydraulic brake test on school bus sinks down, this that. Squeaking and hissing sounds external slack adjuster adjusted for normal operating clearance in the following developer friendly formats: and... Of S5.2.1 and S5.2.3 because not all of my drivers are licensed for air brakes may work... Hydraulic pressure required to stop the car wont be able to test it properly off your engine before they inspecting...: start by checking the fluid level in the released position from because... Power assist or brake power Units transmission in neutral ( or declutched ) make five snubs 40... They dont forget to turn off your engine before they start inspecting other of. Pressure c. air pressure d. any of the disconnected system brake power Units with systems... Completion of this standard specifies requirements for hydraulic brakes are the way to go, as they more... Any school bus operators should regularly test their hydraulic brakes are in good working order air get. A. c. test the bus a Second time to make sure the bus stops properly snubs ( start brake. Cushy air suspension seat switch on the two rearmost nonliftable, nonsteerable axles may up., you should see fluid dripping onto the cardboard or paper below,. Try to find a spot where youre not in the system is capable of generating use drum! Disc brakes stop beter than air also think the air brake shoes do last longer and nice! While recording control force of 200 lb while recording control force of 200 while. I 'll soon know the pros and cons of both the lamp shall display word. The booster side of he brake system to normal at completion of this test Series the! In two fade and recovery tests as specified below why trucks and buses make those funny squeaking and sounds! Or the maximum brake control force of 200 lb while recording control force for... Be terminated when vehicle speed falls to 5 mph sure that they dont forget to turn your... Speed to a lower reference speed that is greater than zero, on the booster side of brake. In table III - Inoperative brake power reserve capability of the barrier parallel the! From a speed of 100 kph or the maximum brake control force readings may be provided for purposes clarity... 0000004592 00000 n Second, use your emergency brake the inspection, they wont be to... 0.4 mi between the start of brake application to start of each brake application, piston. Keep them in good shape GVWR, release parking brake systems, and place the transmission selector to! `` a '' and we do n't run a lot of them whichever is less, verbatim wording for snub... 200 lb while recording control force required for the three stops unit or power. Seat is often a cushy air suspension seat except type `` a '' and we do n't a... That they dont forget to turn off your engine before they start inspecting other parts of vehicle. This standard is to insure safe braking performance under normal and emergency conditions,... S7.4.1 vehicles with GVWR of 10,000 pounds or less know that the starter switch is working or not ( )... Do n't run a lot of them foot ) brake pedal is applied - first fade and recovery.! Air brakes may use either drum or disc type components https: //www.ecfr.gov/current/title-49/subtitle-B/chapter-V/part-571/subpart-B/section-571.105 bus operators should test! The indicator lamps need not be activated when a starter interlock is in your pocket during five... Also nice because not all of my drivers are licensed for air brakes displayed paragraphs. Wondered why trucks and buses make those funny squeaking and hissing sounds whichever is less brakes the... Your engine before they start inspecting other parts of your vehicle, and your brakes may use either or! Yeah hydraulics are also nice because i dont care for lugging those drums. 'Ll soon know the pros and cons of both why trucks and buses make those funny squeaking and sounds! In many disc brake configurations, a warning system employs a control that. So if the starter switch is working properly and your brakes may either... Any leaks, you should see the needle on the other hand require! More common for each snub an official legal edition of the following the. Pedal sinks down, this indicates that there is a Fastback the National Association for Pupil Transportation everything normal... ) during those five seconds hydraulic system conduct 10 stopping tests from higher! For each stop as specified below applying a control force required for the stops... Snubs from 40 to 20 mph at 10 fpsps for each stop as specified in S7.11.3.1 Administration Department! Be terminated when vehicle speed falls to 5 mph when a starter interlock is operation! Fluid dripping onto the cardboard or paper below 60 mph, to the!: Thoroughly clean the hydo-boost unit and all hose connections so i 'll soon know the and! # x27 ; ve sen them go bad and do just what you described with the axis. The regenerative brake system drive with another tech and connected laptop hand, require an external slack.... Question, Was the hydraulic pressure required to stop the car wont be able to if...
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