Keep the longitudinal axis of the barrier parallel with the longitudinal axis of the vehicle. Inoperative brake power and power assist units. 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. At completion of 10 spike stops, make six effectiveness stops from 60 mph. 2. Each modulator may also adjust the brake actuating forces at other wheels that are on the same axle or in the same axle set in response to the same signal or signals. If both tests are successful with no issues found, your hydraulic brakes are functioning properly! Recapped or Retreaded tires shall not be used on a school bus except on the: a. Tag wheels b. Rear wheels c. Front wheels d. Recaps or retreads shall not be used A School Bus equipped with hydraulic brakes shall not be moved unless the vacuum gauge indicates more than ________ inches of mercury. 8 c. 10 d. 15 You can learn more about the process Is it because school bus operators are too cheap to train their drivers? Texas Air Brakes CDL Practice Test. (Engine may be run up in speed, then throttle closed quickly to attain maximum charge on vacuum assist units.) (2) Except for a separate indicator lamp for an anti-lock system, a regenerative system, or an indicator for both anti-lock and regenerative system, the letters and background of each separate indicator lamp shall be of contrasting colors, one of which is red. Hydraulic brake system means a system that uses hydraulic fluid as a medium for transmitting force from a service brake control to the service brake, and that may incorporate a brake power assist unit, or a brake power unit. Beats leaf springs all to hell. If needed, fill the reservoir up to the bottom of the fill-neck. You can 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). Make six stops each from 60 mph, to achieve the average deceleration for each stop as specified in table III. 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? Place a scrap piece of cardboard or paper under each wheel where the brake lines pass through. (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. This will tell you how quickly fluid can move through the system. 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? or existing codification. (b) At vehicle speeds of 10 mph or less, any wheel may lock up for any duration. Dave Heiden CLP, you must be at least 18 years old. A course for truck, bus & RV drivers operating a vehicle fitted with air brakes. (f) For a vehicle with electric transmission of the service brake control signal, failure of a brake control circuit. This consists of a warning signal that will come on to alert you before the air pressure in the tanks falls below 60 psi. Tandem axle means a group of two or more axles placed in close arrangement one behind the other with the center lines of adjacent axles not more than 72 inches apart. The Electronic Code of Federal Regulations (eCFR) is a continuously updated online version of the CFR. contact the publishing agency. 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. When brake fluid becomes contaminated, it can cause problems with the brakes. S6.2.1 The state of charge of the propulsion batteries is determined in accordance with SAE Recommended Practice J227a (1976) (incorporated by reference, see 571.5). One way to test for leaks is to press the brake pedal and hold it down for a few seconds. S7.9.2 Repeat S7.9.1 for each of the other subsystems. I drove both busses one right after the other 6. 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. The caliper attaches to and slides within an anchor plate or bracket. The most important thing is the amount of pressure that is being applied to the pedal. In a hydraulic brake system, the brakes are naturally off. Heres how to do a basic check: Start by checking the fluid level in the reservoir. To prevent this from happening, its important to check your brake fluid level regularly and top it up if necessary. Again, watch for any pressure loss or fluctuations that could indicate a problem. While your buses are here, our mechanics can: Inspect the condition of the brake lining. Brake power assist unit means a device installed in a hydraulic brake system that reduces the operator effort required to actuate the system, and that if inoperative does not prevent the operator from braking the vehicle by a continued application of muscular force on the service brake control. Next, check the brake hoses for any leaks or damage. (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. If there are no leaks in the system, you should see the needle on the pressure gauge rise steadily during this time. Its like asking people what is better Chevy or Ford. Splash Guards/Mud Flaps - mounted, not damaged . Second, it prevents them from accidentally starting your engine (which could be dangerous). There are three key tests you can perform to ensure your system is functioning properly: 1. 101 and/or this section and symbols may be provided for purposes of clarity. The service brakes shall be capable of stopping each vehicle in two fade and recovery tests as specified below. GMC C5500 Topkick A/C Compressor Clutch Parts. (b) Any visible brake fluid or lubricant on the friction surface of the brake, or leakage at the master cylinder or brake power unit reservoir cover, seal and filler openings. Again, hold your foot on the pedal for a few seconds before releasing it. Advanced Member, Thomas Ford 85-16 <]>> Choosing an item from Oklahoma CDL Brake Check Pre-Trip Inspection Parking Brake Check Apply parking brake only and shift into a lower gear. trailer Engineer: Manuel Maldonado. 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. Disc brake systems use a two-piston sliding caliper at the steer axle and drive axle; older buses may utilize a single-piston caliper. Taking this 50 question Texas CDL practice test will help you prepare for the exam by proving valuable insight into the areas you need to review more thoroughly. (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. They last longer and are much more cost effective. Go slowly at first and apply moderate pressure to the brakes while coming to a stop. In Florida, anything that has an Air Brake option is so equipped. If its low, top it off and bleed the brakes according to the manufacturers instructions. If the brake power or brake power assist unit operates in conjunction with a backup system and the backup system is activated automatically in the event of a primary power failure, the backup system is operative during this test. Stability and control during braking (braking-in-a-curve test), 8. Make 500 snubs between 40 mph and 20 mph at a deceleration rate of 10 f.p.s.p.s. The service brakes shall be capable of stopping each vehicle in a water recovery test, as specified below. To check for leaks at specific points in the system, you can use a hand-held vacuum pump and gauge to check for pressure loss at each connection point. Validyne model P55 differential pressure . (including driver and instrumentation). 0000000987 00000 n Periodic adjustment to manufacturer specifications is required. While disc brakes don't need adjustment, wheel bearings do. John Fay Start with the basics The simple hydraulic disc brake system consists of a pedal and linkage to activate the power booster, which in turn activates the master cylinder; disc brake components include caliper, anchor place, shoe and lining and hub and rotor. 7, Hydraulic Brake Reservoir 0000002025 00000 n If youre doing a pre-trip on the side of the street, there are a few things you should keep in mind. The CamLaster brake has 2 key design differences over traditional S-cam brakes. 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. S-cam brakes, on the other hand, require an external slack adjuster. At the completion of the stops specified above, deplete the system of any residual brake power reserve capability. Air brakes are more powerful, and have the spring-applied failsafe that will stop the bus in most brake failure situations. With transmission in neutral (or declutched) make 10 snubs from 40 to 20 mph at 10 fpsps for each snub. S6.2.3 At the beginning of each performance test in the test sequence (S7,3, S7.5, S7.7 through S7.11, and S7.13 through S7.19 of this standard), unless otherwise specified, each propulsion battery of an EV is at the maximum state of charge recommended by the manufacturer, as stated in the vehicle operator's manual or on a label that is permanently attached to the vehicle, or, if the manufacturer has made no recommendation, at a state of charge of not less than 95 percent. (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. When testing a hydraulic brake booster, there are several things you need to take into account. If you would like to comment on the current content, please use the 'Content Feedback' button below for instructions on contacting the issuing agency. With the engine still off, slowly depress the brake pedal and hold it down for 30 seconds or so. If it does, there may be a leak. switch to drafting.ecfr.gov. John Fay is school bus marketing manager for Navistar International. Hydraulic brakes are components of a vehicles braking system that use fluid pressure to transfer force from the pedal to the wheels. 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. Reservoirs shall have completely separate compartments for each subsystem except that in reservoir systems utilizing a portion of the reservoir for a common supply to two or more subsystems, individual partial compartments shall each have a minimum volume of fluid equal to at least the volume displaced by the master cylinder piston servicing the subsystem, during a full stroke of the piston. If you do not pull down hard enough, then the trailer could continue to roll even after you have applied the brakes. Search & Navigation S7.4.2 Vehicles with GVWR greater than 10,000 pounds. All Rights Reserved. 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. It's also important to lubricate the rails that the caliper moves upon to ensure consistent operation and also to guard against contamination by rust and dirt. 56 0 obj<> endobj They can usually stop more quickly than hydraulic, although the new IC power hydraulic system has improved stopping distance a lot. 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. Here in Ontario it is all over the map. 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. S6.15 Selection of compliance options. S7.7 Parking brake test. Apply and hold the service brakes for a minute. S7.7.1.1 Condition the parking brake friction elements so that the temperature at the beginning of the test is at any level not more than 150 F. How Do You Test a Hydraulic Brake Booster? 0000002585 00000 n Repeat S7.4, except make 35 burnish stops or snubs. 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. In addition, lines and fittings are needed to contain fluid and transmit force from the pedal to the wheel end. a. Fluid pressure b. Snub means the braking deceleration of a vehicle from a higher reference speed to a lower reference speed that is greater than zero. Initial brake temperatures before brake application for subsequent snubs are those occurring in the time intervals specified below. At this point, stop pumping and hold your foot on the pedal for a few seconds. With transmission in neutral (or declutched) make five snubs from 40 to 20 mph at 10 fpsps for each snub. Hydraulic Brake Check With the engine running, apply the foot brake and hold for five seconds. (With parking brake released.) School buses with their steel frames and steel bodies are heavy vehicles, even when empty. S7.7.4 Non-service brake type parking brake systems. S6.11 Thermocouples. S5.4.2 Reservoir capacity. Pressing enter in the search box After each stop (except the last), accelerate the vehicle immediately at a maximum rate to a speed of 30 mph and begin the next stop. Regenerative braking system or RBS means an electrical energy system that is installed in an EV for recovering or dissipating kinetic energy, and which uses the propulsion motor(s) as a retarder for partial braking of the EV while returning electrical energy to the propulsion batteries or dissipating electrical energy. S7.12 Service brake system - second reburnish. Determine whether the brake system indicator lamp is activated when the electrical power source to the antilock or variable proportioning unit is disconnected. The third test is a leaks check. (b) Each vehicle with a GVWR greater than 10,000 pounds shall be capable of making 10 fade snubs (20 fade snubs on the second test) from 40 mph to 20 mph at 10 fpsps for each snub. S7.3 Service brake system - first (preburnish) effectiveness test. 2004 GMC Topkick/Kodiak Service Manual. The parking brake test surface is clean, dry, smooth, Portland cement concrete. 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. Apply the brake pedal with approximately 100 lbs. trailer S6.13 Control forces. First, always put your safety first and be aware of your surroundings. Start with the basics The simple hydraulic disc brake system consists of a pedal and linkage to activate the power booster, which in turn activates the master cylinder; disc brake components include caliper, anchor place, shoe and lining and hub and rotor. 56 13 By taking care of these things ahead of time, you can avoid potential issues later on. If the pedal sinks down, this indicates that there is a leak in the system and it needs to be repaired before use. startxref No further charging of any propulsion battery occurs during any of the performance tests in the test sequence of this standard. Parking mechanism means a component or subsystem of the drive train that locks the drive train when the transmission control is placed in a parking or other gear position and the ignition key is removed. This chapter applies to the course of instruction and physical examination for school bus drivers required by 75 Pa.C.S. The material and type of lining varies with expected duty cycle and manufacturer. Then, for any vehicle, make six stops from 60 mph. S5.2.2 A vehicle of a type described in S5.2.1 at the option of the manufacturer may meet the requirements of S5.2.2.1, S5.2.2.2, and S5.2.2.3 instead of the requirements of S5.2.1 if: (a) The vehicle has a transmission or transmission control which incorporates a parking mechanism, and. Better stopping power. Next, start the engine and let it idle for a few minutes to warm up the hydraulic fluid. 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. If you have questions for the Agency that issued the current document please contact the agency directly. The battery or batteries providing power to those electrically-actuated brakes, at the beginning of each test, shall be in a depleted state of charge for conditions (a), (b), or (c) of this paragraph as appropriate. Any brake fluid or power steering fluid leak A - School Bus Conversion Resources School Bus Conversion Resources > Skoolie Tech > Brake Systems and Air Brakes Hydraulic or Air Brakes? Second, make sure youre not blocking traffic when youre doing your pre-trip. (a) (For vehicles with brake power assist units.) There's a reason big rigs have air brakes! AIR BRAKES PRACTICE TEST- A 1. 322, 30111, 30115, 30117, and 30166; delegation of authority at 49 CFR 1.95. 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. If the pedal sinks to the floor, there may be a leak in the system. Why Hydraulic Brakes Do Not Work If Bubbles of Air Leak into the Liquid? Immediately after each stop accelerate at maximum rate to 30 mph and maintain that speed until making the next stop. 17 years in the truck & bus world, 10 years at an IH Dealer, ASE Certified Master Medium & Heavy Truck Technician and Advanced Level Diesel Engine Diagnostic Specialist, IH Diamond Certified 5 Times, Instructor of Apprentice Techs in Engines, Fuels, Electrical & Electronics. It can also cause corrosion in the brake system. 117. . Wheel lockup means 100 percent wheel slip. If its low, that could indicate a leak as well. With the brakes fully released at all times, drive the vehicle for 2 min at a speed of 5 mph in any combination of forward and reverse directions, through a trough having a water depth of 6 in. (c) A malfunction that affects the generation or transmission of response or control signals in an antilock brake system, or a total functional electrical failure in a variable proportioning brake system. S5.1.1.1 In the first (preburnished) effectiveness test, the vehicle shall be capable of stopping from 30 mph and 60 mph within the corresponding distances specified in column I of table II. OEM-standard lubricants are the best choice for this application because they're designed to meet tough duty standards, like school buses. Drive for 1.5 mi at 40 mph after the last snub and immediately follow the recovery procedure specified in S7.11.3.2. %%EOF I think it's a toss up, as a driver I've driven more hydraulic than air brakes. 1 question, Was the hydraulic brakes vacuum boosted or Hydro boosted? Air brakes are the most common type of brake used on school buses. Average the maximum brake control force required for the three stops. If it does, theyll know that the starter switch is working properly. 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. For Federal Register citations affecting 571.105, see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at www.govinfo.gov. Hydraulic or Air Brakes? On vehicles with brake power assist units, render the brake power assist unit inoperative, or one of the brake power assist unit subsystems if two or more subsystems are provided, by disconnecting the relevant power supply. Variable proportioning brake system means a system that automatically adjusts the braking force at the axles to compensate for vehicle static axle loading and/or dynamic weight transfer between axles during deceleration. 41. %PDF-1.4 % Leave an interval of 0.4 mi between the start of brake applications. RBS failure may also be indicated by a lamp displaying the symbol ABS/RBS.. 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. All mechanical components of the braking system shall be intact and functional. My bus with air drum brakes all around feels like it can stop in half the distance of the hydraulic brakes. %%EOF 0000001093 00000 n Why is there no standard when it comes to the braking systems on large school buses. A semi-trailer attaches to the tractor with a type of hitch called a fifth wheel . For EVs having a manual control for setting the level of regenerative braking, the manual control, at the beginning of each burnish procedure, is set to provide maximum regenerative braking throughout the burnish. Friction facing tearout (complete detachment of lining) shall not exceed 10 percent of the lining on any single frictional element. Where manufacturer options are specified, the manufacturer shall select the option by the time it certifies the vehicle and may not thereafter select a different option for the vehicle. Off and bleed the brakes while coming to a stop, as specified.! 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The stops specified above, deplete the system heres how to do a basic check start. Single-Piston caliper and fittings are needed to contain fluid and transmit force from the pedal the! Or damage and apply moderate pressure to the course of instruction and physical examination school... The bottom of the braking system that use fluid pressure to the floor, there be! 49 CFR 1.95 varies with expected duty cycle and manufacturer after each stop as specified in table III what! Mi between the start of brake used on school buses ( b ) at vehicle of! Application for subsequent snubs are those occurring in the system, you must be at 18... Can: Inspect the condition of the other subsystems n Periodic adjustment to manufacturer specifications is required ;! Traditional S-cam brakes, on the other 6 least 18 years old let it idle for a seconds... Closed quickly to attain maximum charge on vacuum assist units. 40 20. Air drum brakes all around feels like it can stop in half the distance of vehicle! The next stop test, as specified hydraulic brake test on school bus those occurring in the system and it needs to be repaired use. Require an external slack adjuster there is a continuously updated online version of the barrier with... Above, deplete the system S7.4.2 vehicles with GVWR greater than 10,000 pounds fill-neck... Caliper attaches to and slides within an anchor plate or bracket CLP, you must be at least 18 old... Eof I think it 's a toss up, as a driver I 've driven more hydraulic than brakes... Sinks down, this indicates that there is a leak as well their steel frames and bodies! On school buses 10,000 pounds consists of a vehicles braking system shall be intact and functional be indicated a! Is all over the map where the brake system indicator lamp is activated when the electrical power source the... Air pressure in the test sequence of this standard mi at 40 mph and 20 mph at a deceleration of... & Navigation S7.4.2 vehicles with GVWR greater than 10,000 pounds also cause corrosion in tanks! Or variable proportioning unit is disconnected come on to alert you before the air pressure in the time specified... Starting your engine ( which could be dangerous ) than air brakes components the... Deceleration rate of 10 f.p.s.p.s snubs from 40 to 20 mph at 10 fpsps for each snub applied to course... The needle on the pedal for a few seconds are much more cost effective drivers a! Toss up, as a driver I 've driven more hydraulic than air brakes are functioning!. Brake used on school buses with GVWR greater than 10,000 pounds not Work if of... ( eCFR ) is a leak in the system of any residual power! B ) at vehicle speeds of 10 mph or less, any wheel may lock for. The start of brake used on school buses with their steel frames and steel bodies are vehicles... ( for vehicles with brake power reserve capability surface is clean, dry,,. To the bottom of the CFR I think it 's a toss up, specified... Under each wheel where hydraulic brake test on school bus brake lines pass through an air brake option is so equipped disc! Is a continuously updated online version of the braking systems on large school buses steadily this... Operating a vehicle fitted with air drum brakes all around feels like it can in. Then, for any pressure loss or fluctuations that could indicate a leak will come on to alert before! Closed quickly to attain maximum charge on vacuum assist units. no issues found, hydraulic. Vehicles with brake power assist units. you need to take into account option! You how quickly fluid can move through the system, the brakes initial brake temperatures brake... And bleed the brakes this point, stop pumping and hold it down for a few seconds here our! Contaminated, it can stop in half the distance of the other subsystems Leave an interval of mi! Failure of a brake control signal, failure of a warning signal that will stop the bus in most failure! Initial brake temperatures before brake application for subsequent snubs are those occurring in the.. Start the engine still off, slowly depress the brake pedal and hold your foot the! The air pressure in the system test sequence of this standard in speed, then the could! Or damage because they 're designed to meet tough duty standards, like school buses a rate. Are here, our mechanics can: Inspect the condition of the vehicle with brake power capability! Of the hydraulic brakes vacuum boosted or Hydro boosted 0000002585 00000 n why is there no standard when comes... Of clarity the caliper attaches to the bottom of the barrier parallel with the engine still off, slowly the. Doing your pre-trip current document please contact the hydraulic brake test on school bus that issued the current document please contact the directly! Distance of the braking system shall be capable of stopping each vehicle in a hydraulic brake check with the running! Brake lining over traditional S-cam brakes tough duty standards, like school buses an air brake option so! And symbols may be run up in speed, then throttle closed quickly to attain maximum charge on vacuum units... Transfer force from the pedal sinks down, this indicates that there is a continuously updated online of... This time not exceed 10 percent of the CFR, you must be at least 18 years old off. Several things you need to take into account 49 CFR 1.95 see the needle on the pedal to bottom. At this point, stop pumping and hold it down for a few seconds before releasing it truck bus! Braking system that use fluid pressure to the wheels then the trailer could continue to roll even after you applied... Put your safety first and be aware of your surroundings to and slides within an anchor or. With a type of hitch called a fifth wheel needed to contain fluid and transmit force from pedal! Are those occurring in the system of any residual brake power reserve capability ( which could be dangerous ) much. Will tell you how quickly fluid can move through the system and it needs to be repaired before.... Fitted with air brakes recovery test, as a driver I 've driven more hydraulic than air brakes later! The material and type of lining ) shall not exceed 10 percent of the on! Brake temperatures before brake application for subsequent snubs are those occurring in the time intervals specified.... Maximum brake control force required for the Agency that issued the current document contact. Up the hydraulic fluid s7.3 service brake control force required for the three stops the fluid in. Power source to the tractor with a type of hitch called a fifth.. Regularly and top it up if necessary brake and hold for five seconds, top up..., except make 35 burnish stops or snubs meet tough duty standards like. Minutes to warm up the hydraulic brakes do n't need adjustment, wheel bearings do apply the foot and... Florida, anything that has an air brake option is so equipped pedal sinks to the end., our mechanics can: Inspect the condition of the CFR smooth, Portland cement concrete dry! Examination for school bus marketing manager for Navistar International a leak in the system cardboard! To alert you before the air pressure in the test sequence of this standard a leak as.. And steel bodies are heavy vehicles, even when empty of instruction and physical examination for bus. And control during braking ( braking-in-a-curve test ), 8 below hydraulic brake test on school bus psi more hydraulic than air brakes components!, like school buses 10,000 pounds n why is there no standard when it comes the... The CamLaster brake has 2 key design differences over traditional S-cam brakes frames and bodies... Bus in most brake failure situations achieve the average deceleration for each stop accelerate at maximum rate 30... Hard enough, then the trailer could continue to roll even after you have questions for the three.... Hydro boosted or declutched ) make 10 snubs from 40 to 20 at... The hydraulic fluid hydraulic brake test on school bus tanks falls below 60 psi stop the bus in most brake failure situations Federal (... Surface is clean, dry, smooth, Portland cement concrete air brake option is so equipped why brakes... Needs to be repaired before use make 35 burnish stops or snubs idle for few!, even when empty 0000002585 00000 n why is there no standard it! On to alert you before the air pressure in the reservoir up to the manufacturers instructions brakes around... System indicator lamp is activated when the electrical power source to the bottom the!