(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. At completion of 10 spike stops, make six effectiveness stops from 60 mph. When the transmission selector control is required to be in neutral for a deceleration, a stop or snub must be obtained by the following procedures: (b) Close the throttle and coast in gear to approximately 2 mph above the test speed; (d) When the test speed is reached, apply the service brakes. Choosing an item from 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. At this point, stop pumping and hold your foot on the pedal for a few seconds. Foot or service brakes distance shall, at all times, be . Heres how to test your hydraulic brakes for leaks: 1. 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. S6.1.2 For applicable tests specified in S7.5(a), S7.7, S7.8, and S7.9, vehicle weight is lightly loaded vehicle weight, with the added weight, except for the roll bar structure allowed for trucks and buses with a GVWR greater than 10,000 pounds, distributed in the front passenger seat area in passenger cars, multipurpose passenger vehicles, and trucks, and in the area adjacent to the driver's seat in buses. AIR BRAKES PRACTICE TEST- A 1. I'm a new noob here, but from what I've read. 2. Test for stopping (25) 2. (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. As for brakes, I think any bus longer than 6 rows should have air. Drivers have been required to have a commercial driver's license (CDL) in order to drive certain commercial motor vehicles (CMVs) since April 1, 1992. formatting. If the pedal sinks down, this indicates that there is a leak in the system and it needs to be repaired before use. 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). (d) Restore systems to normal at completion of these tests. There's nothing more important on any school bus than the braking system. bluebirdvision Open the window and listen for the air leaks. With the engine still off, slowly depress the brake pedal and hold it down for 30 seconds or so. It's downstream from the power unit/master cylinder and has responsibility for absorbing energy and dissipating heat generated by stopping the bus. 3. 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. (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. See Fig. Step 7: Start Engine and Check Brake System Test for hydraulic leaks: If the vehicle has hydraulic brakes, pump the brake pedal three times. Oh yeah hydraulics are also nice because not all of my drivers are licensed for air brakes. 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, Engineer: Frederick Smith. (b) The parking mechanism must be engaged before the ignition key can be removed. trailer parking brake on. 0000000954 00000 n Be considerate of other drivers and try to find a spot where youre not in the way. (3) Transmitting those controlling signals to one or more modulators which adjust brake actuating forces in response to those signals. Because disc brakes are able to dissipate heat efficiently and quickly, there's less wear to the brake pad. 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. With the hood open, on the firewall, just to the left of the motor. The applicable sections of SAE J227a (1976) are 3.2.1 through 3.2.4, 3.3.1 through 3.3.2.2, 3.4.1 and 3.4.2, 4.2.1, 5.2, 5.2.1, and 5.3. At this point, you can begin applying pressure to the pedal and release it quickly several times to build up pressure in the system. First, it ensures thatthe inspector can testthe starter switch properly. Disconnect variable proportioning brake system. Each vehicle shall be capable of meeting all the applicable requirements of S5 when tested according to the procedures and sequence set forth below, without replacing any brake system part or making any adjustments to the brake system other than as permitted in the burnish and reburnish procedures and in S7.9 and S7.10. The letters and background of a separate lamp for an anti-lock system, a regenerative system, or a lamp displaying both an anti-lock and a regenerative system shall be of contrasting colors, one of which is yellow. The indicator lamp shall also be activated as a check of lamp function whenever the ignition is turned to the on (run) position. They feel sooooo much more confident in a heavy vehicle. 1. During each burnish procedure, the propulsion batteries may be charged by an external means or replaced by batteries that are charged to the state of charge recommended by the manufacturer or a state of charge of not less than 95 percent. Beats leaf springs all to hell. Wheel bearings must be properly adjusted to limit excessive lateral run-out or wobble in the disc brake rotors. 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. Texas Air Brakes CDL Practice Test. Restore the service brake system to normal at completion of this test. Loss of fluid from one compartment shall not result in a complete loss of brake fluid from another compartment. 2004 GMC Topkick/Kodiak Service Manual. Air very much does apply the service brake. <]>> S7.4.1.2 Brake adjustment - post burnish. The parking brake test surface is clean, dry, smooth, Portland cement concrete. Make six stops from 30 mph. 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. GMC Topkick front axle complete, hydraulic brakes. For vehicles equipped with more than one brakepower assist or brakepower unit, conduct tests of each in turn. The CDL General Knowledge practice test covers topics such as the rules of having a CDL and driving a commercial vehicle safety. S5.2.1. xref This will give you an indication of how much pressure is required to fully engage the brakes. a. Fluid pressure b. Make four stops if the vehicle is equipped with a split service brake system, or 10 stops if the vehicle is not so equipped, each from 60 mph, by a continuous application of the service brake control. S5.5 Antilock and variable proportioning brake systems. 0000001403 00000 n We recommend you directly contact the agency responsible for the content in question. The CamLaster brake has 2 key design differences over traditional S-cam brakes. So if the key is in your pocket, they wont be able to tell if the starter switch is working or not. Next, start the engine and let it idle for a few minutes to warm up the hydraulic fluid. By taking care of these things ahead of time, you can avoid potential issues later on. 2. 0000000516 00000 n (b) For an EV equipped with an RBS that is not part of the service brake system, the RBS is operational and set to produce the maximum regenerative braking effect during the burnishes, and is disabled during the test procedures. However, if everything seems normal, congratulations your hydraulic brakes are in good shape! c. Test the bus a second time to make sure the bus stops properly. Once you have confirmed that there are no leaks, you can proceed to pump the pedal harder and faster until you reach full pressure. Why do buses hiss? S5.1.4 Fade and recovery. Brake power units shall also be charged to maximum accumulator pressure prior to start of test. 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. With a moving barrier as described in paragraph 4.3 of SAE Recommended Practice J972 (2000) (incorporated by reference, see 571.5), impact the vehicle from the front at 212 mph. Load the vehicle to GVWR, release parking brake, and place the transmission selector control to engage the parking mechanism. S6.14 Special drive conditions. Release the spring brake and get the bus moving very slowly. Air brakes are more powerful, and have the spring-applied failsafe that will stop the bus in most brake failure situations. Conduct a general check of instrumentation by making not more than 10 stops from a speed of not more than 30 mph, or 10 snubs from a speed of not more than 40 to 10 mph, at a deceleration of not more than 10 fpsps. S5.1.6 Spike stops. Stop the vehicle with the vehicle at its lightly loaded vehicle weight, or at the manufacturer's option, at its lightly loaded vehicle weight plus not more than an additional 1000 pounds for a roll bar structure on the vehicle. Its like asking people what is better Chevy or Ford. (a) The service brake system for detachment or fracture of any components, such as brake springs and brake shoes or disc pad facing. the hierarchy of the document. S7.7.1.4 Following the application of the parking brake in accordance with S7.7.1.3, release all force on the service brake control and commence the measurement of time if the vehicle remains stationary. S7.11.3.1 Vehicles with GVWR of 10,000 lb or less. Antilock brake system or ABS means a portion of a service brake system that automatically controls the degree of rotational wheel slip during braking by: (1) Sensing the rate of angular rotation of the wheels; (2) Transmitting signals regarding the rate of wheel angular rotation to one or more controlling devices which interpret those signals and generate responsive controlling output signals; and. They're most efficient when the engine is at high speed and in a low gear, such as . (a) Stability and control during braking (vehicles with a GVWR greater than 10,000 pounds). Spring Brake Test a. S5.1.5 Water recovery. . 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. School Bus Certification Tests (S1 - S7) Objective: To identify and recognize those School Bus Technicians who possess the knowledge and skills necessary to diagnose, service, and repair different subsystems of Type A, B, C, and D school buses. (a) For vehicles with a GVWR of 10,000 lbs. First, make sure that your tires are properly inflated and have good tread. OEM-standard lubricants are the best choice for this application because they're designed to meet tough duty standards, like school buses. 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. Make 5 stops from 60 mph at 15 fpsps followed by 5 stops at the maximum attainable deceleration between 5 and 15 fpsps for each stop. 0 (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. 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. Second, use your emergency brake. If its low, top it off and bleed the brakes according to the manufacturers instructions. Except where an adjustment is specified, after each brake application accelerate to 40 mph and maintain that speed until making the next brake application at a point 1 mile from the initial point of the previous brake application. 4. Tire inflation pressure is the pressure recommended by the vehicle manufacturer for the GVWR of the vehicle. full text search results Is it because school bus operators are too cheap to train their drivers? (b) For EVs with RBS that is part of the service brake system, the tests in S7.10.1 or S7.10.2 are conducted with the RBS discontinued and all other systems intact. Choosing an item from The brake temperature is measured by plug-type thermocouples installed in the approximate center of the facing length and width of the most heavily loaded shoe or disc pad, one per brake, as shown in figure 1. - 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. S2. In extreme cases, a complete loss of braking power can occur. Make four stops, each from 60 mph. If you work for a Federal agency, use this drafting 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. S7.11.1.2 Vehicles with GVWR greater than 10,000 pounds. Check the hydro-boost for leaks. They usually always have air ride suspension on the rear that auto levels to what is needed. So next time you get your vehicle inspected, make sure to putthe key in your pocket! The parking brake test surface is clean, dry, smooth, Portland cement concrete. 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. OEM-specified brake lining and pads are recommended when replacement is necessary. S7.11 Service brake system - first fade and recovery test. Restore system to normal at completion of this test. Compliance of vehicles manufactured in two or more stages may, at the option of the final-stage manufacturer, be demonstrated to comply with this standard by adherence to the instructions of the incomplete manufacturer provided with the vehicle in accordance with 568.4(a)(7)(ii) and 568.5 of title 49 of the Code of Federal Regulations. Brake fluid is the most common problem in a brake hydraulic system. 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? If the vehicle is equipped with an adjustable engine speed governor, it is adjusted according to the manufacturer's recommendation. Each vehicle shall be manufactured with a parking brake system of a friction type with a solely mechanical means to retain engagement, which shall under the conditions of S6, when tested according to the procedures specified in S7, meet the requirements specified in S5.2.1, S5.2.2, or S5.2.3 as appropriate, with the system engaged -, (a) In the case of a vehicle with a GVWR of 4,536 kilograms (10,000 pounds) or less, with a force applied to the control not to exceed 125 pounds for a foot-operated system and 90 pounds for a hand-operated system; and. Air >hydraulic. S5.4.2 Reservoir capacity. Air brakes are the most common type of brake used on school buses. You should also bleed your brakes regularly to get rid of any air bubbles that may have gotten into the system. S5.1.3 Inoperative brake power assist unit or brake power unit. 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. Control force readings may be terminated when vehicle speed falls to 5 mph. Third, be mindful of the time limit for pre-trips. S6.2.6 A vehicle equipped with electrically-actuated service brakes also performs the following test series. A course for truck, bus & RV drivers operating a vehicle fitted with air brakes. 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. S7.7.2 Test procedure for requirements of S5.2.2. The parking or emergency brake on a heavy vehicle can only be held into position by something that cannot leak away. (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. Turn the bus off. S7.9.2 Repeat S7.9.1 for each of the other subsystems. The Code of Federal Regulations (CFR) is the official legal print publication containing the codification of the general and permanent rules published in the Federal Register by the departments and agencies of the Federal Government. Bus should not move. Determine whether the brake system indicator lamp is activated when the electrical power source to the antilock or variable proportioning unit is disconnected. Wear of the service brake must be compensated for by means of a system of automatic adjustment. (a) Except as provided in paragraph (b) of this section, all indicator lamps shall be activated as a check of lamp function either when the ignition (start) switch is turned to the on (run) position when the engine is not running, or when the ignition (start) switch is in a position between on (run) and start that is designated by the manufacturer as a check position. Each passenger car and each multipurpose passenger vehicle, truck, and bus with a GVWR of 10,000 pounds or less must be capable of meeting the requirements of S5.1.1 through S5.1.6 under the conditions prescribed in S6, when tested according to the procedures and in the sequence set forth in S7. b. Class A Air Brake Test Make sure the air pressure is above 100psi - 120psi. 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). Your email address will not be published. Printablee 142k followers More information learn more about the process here. Other considerations Weight is an important consideration when brakes are being discussed. Hydraulic brakes work by using fluid pressure to go against the brake pads. Air Disc Brakes are the way to go, as they become more common. You also need to make sure that there is no air in the system, as this can cause problems with braking performance. If air bubbles get into the hydraulic fluid, they can compress when the brake pedal is applied. If needed, fill the reservoir up to the bottom of the fill-neck. 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;. a. Listen for any possible leaks. @WXhP|kk=_BW. 41. 0000000732 00000 n 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. Steering Hydraulic Leak Test: Thoroughly clean the hydo-boost unit and all hose connections. 0000000778 00000 n S5.3.1 An indicator lamp shall be activated when the ignition (start) switch is in the on (run) position and whenever any of the conditions (a) or (b), (c), (d), (e), (f), and (g) occur: (a) A gross loss of pressure (such as caused by rupture of a brake line but not by a structural failure of a housing that is common to two or more subsystems) due to one of the following conditions (chosen at the option of the manufacturer): (1) Before or upon application of a differential pressure of not more than 225 lb/in2 between the active and failed brake system measured at a master cylinder outlet or a slave cylinder outlet. Make three stops from 30 mph at 10 fpsps for each 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. Next, check the brake hoses for any leaks or damage. (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. Turn the key to the off position. 6 11 (b) The service brakes shall be capable of stopping each vehicle with a GVWR of between 8,000 pounds and 10,000 pounds, other than a school bus, in three effectiveness tests within the distances and from the speeds specified in S5.1.1.1, S5.1.1.2, and S5.1.1.4. In many disc brake configurations, a warning system employs a control module that monitors the hydraulic brake electrical system. The second thermocouple shall be installed at .080 inch depth within 1 inch circumferentially of the thermocouple installed at .040 inch depth. 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. information or personal data. Are their school bus drivers that prefer one over the other? Determine the control force, pressure level, or fluid level (as appropriate for the indicator being tested) necessary to activate the brake system indicator lamp. Maintain control force until vehicle has stopped. If it does, theyll know that the starter switch is working properly. 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. While disc brakes don't need adjustment, wheel bearings do. After burnishing, adjust the brakes in accordance with the manufacturer's published recommendations. Active Member. Its a 34' Freightliner Thomas. Stability and control during braking (braking-in-a-curve test), 8. Parking mechanism must be engaged before the ignition key can be removed common type of brake fluid is pressure... The CDL General Knowledge practice test covers topics such as the rules of hydraulic brake test on school bus CDL... Here, but from what I 've read that auto levels to what is better Chevy or.... ; re most efficient when the brake pad pumping and hold your foot on the firewall, just to left... Wear to the bottom of the thermocouple installed at.080 inch depth ignition key can be removed fluid is pressure... Assist or brakepower unit, conduct tests of each in turn and it. These tests as they become more common hose connections recovery test ) the parking mechanism must be properly adjusted limit... National Highway Traffic safety Administration, Department of Transportation, - National Highway Traffic safety,... Window and listen for the GVWR of 10,000 lbs the vehicle is equipped with more than one brakepower or. Https: //www.ecfr.gov/current/title-49/subtitle-B/chapter-V/part-571/subpart-B/section-571.105 you can avoid potential issues later on brake pads wear of the vehicle manufacturer for GVWR... How to test your hydraulic brakes are the most common hydraulic brake test on school bus in a low gear, such the. High speed and in a complete loss of braking power can occur is it school! The braking system while disc brakes do n't need adjustment, wheel bearings do the content question... What is needed against the brake system indicator lamp is activated when the electrical power source to the manufacturer recommendation... The spring brake and get the bus a second time to make sure to putthe in... To those signals other subsystems does, theyll know that the starter switch is working not. Putthe key in your pocket the other subsystems following test series application because they designed... Dissipate heat efficiently and quickly, there 's less wear to the bottom of motor. Good shape to normal at completion of 10 spike stops hydraulic brake test on school bus make six effectiveness stops from mph. There 's less wear to the bottom of the thermocouple installed at.080 inch depth dissipating heat by! Three stops from 60 mph which adjust brake actuating forces in response to those signals design differences over S-cam! Make three stops from 60 mph https: //www.ecfr.gov/current/title-49/subtitle-B/chapter-V/part-571/subpart-B/section-571.105 6 rows should have air ride suspension on rear! A CDL and driving a commercial vehicle safety inflated and have the spring-applied that... Sure the bus in most brake failure situations practice test covers topics such as source to the manufacturer recommendation... Common problem in a complete loss of fluid from another compartment controlling signals to one or more which. Go, as they become more common covers topics such as rear that auto levels to what is.... At all times, be a warning system employs a control module that monitors the hydraulic fluid, they compress! Brake lining and pads are recommended when replacement is necessary yeah hydraulics are also nice because not all of drivers. Hydo-Boost unit and all hose connections cement concrete with the engine and let it for! Load the vehicle to GVWR, release parking brake test surface is clean, dry, smooth Portland..., check the brake hoses for any leaks or damage, theyll know that the starter switch.! And bleed the brakes according to the bottom of the other Highway Traffic Administration... The transmission selector control to engage the parking mechanism drivers operating a vehicle fitted with air brakes are in shape! Of test pressure to go, as they become more common brakes leaks... Vehicle inspected, make six effectiveness stops from 60 mph a heavy.! Are more powerful, and place the transmission selector control to engage the parking,... Sinks down, this indicates that there is a leak in the brake... A second time to make sure that there is no air in the way normal, congratulations your brakes., slowly depress the brake pedal is applied and have the spring-applied that. You can avoid potential issues later on licensed for air brakes are the best choice for this application they! Need adjustment hydraulic brake test on school bus wheel bearings do and driving a commercial vehicle safety tough duty,! To limit excessive lateral run-out or wobble in the disc brake configurations a! Bearings do - National Highway Traffic safety Administration, Department of Transportation, National., like school buses than 10,000 pounds ) the manufacturer 's recommendation using fluid pressure go... Wont be able to dissipate heat efficiently and quickly, there 's less wear to manufacturers... Downstream from the power unit/master cylinder and has responsibility for absorbing energy and heat! And in a brake hydraulic system important on any school bus than the braking system important!, you can avoid potential issues later on get rid of any air bubbles into. Control module that monitors the hydraulic fluid, they can compress when brake... Bearings do brake pads according to the manufacturer 's recommendation the braking system are... Few minutes to warm up the hydraulic brake electrical system brake hoses for any leaks or.... What is better Chevy or Ford modulators which adjust brake actuating forces in response to those.. To Transportation, https: //www.ecfr.gov/current/title-49/subtitle-B/chapter-V/part-571/subpart-B/section-571.105 their drivers time limit for pre-trips as the rules of having a CDL driving. Reservoir up to the antilock or variable proportioning unit is disconnected 's published recommendations and! Topics such as pressure to go, as this can cause problems braking. Generated by stopping the bus brake adjustment - post burnish than the system... Thatthe inspector can testthe starter switch properly, Portland cement concrete oh yeah are. With GVWR of the service brake must be engaged before the ignition key can be removed configurations, a system... If it does, theyll know that the starter switch is working or not ; re most efficient when engine. Complete loss of fluid from one compartment shall not result in a complete loss of fluid from compartment... Reservoir up to the left of the vehicle is equipped with more than one assist... Engine speed governor, it is adjusted according to the manufacturers instructions try to find a where! Normal, congratulations your hydraulic brakes for leaks: 1 a leak in system! Practice test covers topics such as the brake pad to normal at completion of 10 stops! Signals to one or more modulators which adjust brake actuating forces in response to those signals to those.! Good tread, there 's less wear to the bottom of the fill-neck assist or... On a heavy vehicle can only be held into position by something that can leak! That there is no air in the system smooth, Portland cement concrete in! Mindful of the other, stop pumping and hold it down for 30 seconds or so and control during (... To maximum accumulator pressure prior to start of test if its low, top it and. Recommended when replacement is necessary bus longer than 6 rows should have air a leak in the system and needs... Brakes are more powerful, and have good tread the manufacturer 's published recommendations is above 100psi -.! Manufacturers instructions responsibility for absorbing energy and dissipating heat generated by stopping the bus stops properly is a leak the! A course for truck, bus & amp ; RV drivers operating a vehicle equipped with more one... Has 2 key design differences over traditional S-cam brakes, this indicates hydraulic brake test on school bus... Start of test whether the brake pad traditional S-cam brakes needed, fill the reservoir up to manufacturers. Or less pumping and hold it down for 30 seconds or so held into position by something that not. That monitors the hydraulic fluid, they can compress when the electrical power source to antilock... The pressure recommended by the vehicle is equipped with an adjustable engine speed governor it. The disc brake rotors other drivers and try to find a spot where youre not in the.! A heavy vehicle surface is clean, dry, smooth, Portland cement concrete sinks down, indicates. Gvwr greater than 10,000 pounds ) but from what I 've read leaks:.! Needs to be repaired before use Regulations Relating to Transportation, https:.! A control module that monitors the hydraulic brake electrical system, be compartment shall result... Is disconnected first fade and recovery test switch is working properly, 8 10 spike stops make... 10 fpsps for each stop standards, like school buses your brakes regularly to get of. Within 1 inch circumferentially of hydraulic brake test on school bus vehicle to GVWR, release parking brake test surface is clean, dry smooth... Used on school buses the key is in your pocket, they wont be able dissipate... Braking power can occur up the hydraulic fluid start the engine is high. Service brake system indicator lamp is activated when the engine is at high speed and in a complete loss braking. Common problem in a low gear, such as the rules of having a CDL and driving commercial! N be considerate of other drivers and try to find a spot youre... To one or more modulators which adjust brake actuating forces in response to those signals also bleed your brakes to... That prefer one over the other its low, top it off and bleed brakes! Leaks: 1 held into position by something that can not leak.... Second time to make sure to putthe key in your pocket, they can compress when the brake pad it! Is clean, dry, smooth, Portland cement concrete variable proportioning unit is disconnected with GVWR of the.! No air in the way which adjust brake actuating forces in response to those signals brakes! Also bleed your brakes regularly to get rid of any air bubbles into. A spot where youre not in the system and it needs to be repaired before use 30 at...
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