(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. 135. Directly Controlled Wheel means a wheel for which the degree of rotational wheel slip is sensed, either at that wheel or on the axle shaft for that wheel and corresponding signals are transmitted to one or more modulators that adjust the brake actuating forces at that wheel. (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. i think the disc brakes stop beter than air also. S6 Test conditions. This chapter cited in 22 Pa. Code 51.92 (relating to school bus operators); and 67 Pa. Code 231.8 (relating to additions or modifications to 49 CFR). 8 0 obj<>stream Our trained mechanics know how to work on all makes and models of school buses. Here in Ontario it is all over the map. 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. 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. When you are towing a trailer, the more weight that is on the trailer, the harder you will need to pull down on the lever to activate the brakes. Snub means the braking deceleration of a vehicle from a higher reference speed to a lower reference speed that is greater than zero. S6.10.2 For vehicles with a GVWR greater than 10,000 pounds, stops are made with wheel lockup permitted only as follows: (a) At vehicle speeds above 20 mph, any wheel on a nonsteerable axle other than the two rearmost nonliftable, nonsteerable axles may lock up for any duration. All Rights Reserved. The material and type of lining varies with expected duty cycle and manufacturer. RBS failure may also be indicated by a lamp displaying the symbol ABS/RBS.. Which of the following makes the total stopping distance for air brakes longer than that for hydraulic brakes? It is not an official legal edition of the CFR. 2. Unless otherwise specified the brake temperature is 150 F. 49 CFR 172.101 While disc brakes don't need adjustment, wheel bearings do. To receive this license, applicants must pass a 50-question test. FY TP-116-04. Air brakes are used on most large commercial vehicles and use compressed air to operate the brakes. Visually inspect the brake pad lining by checking each visible end and look through the opening of the caliper. Spring pressure c. Air pressure d. Any of the above 2. The Federal Motor Carrier Safety Administration (FMCSA) has developed and issued standards for State testing and licensing of CDL holders. The Office of the Federal Register publishes documents on behalf of Federal agencies but does not have any authority over their programs. Initial brake temperature means the average temperature of the service brakes on the hottest axle of the vehicle 0.2 mi before any brake application. 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. Test as in S7.10.2(a), except make 10 stops instead of 6 and, at the completion of the 10 stops, deplete the failed element of the brake power unit of any residual brake power reserve capability before making the final stop. John Fay is school bus marketing manager for Navistar International. By regularly performing these three tests, you can catch potential problems early and keep your hydraulic system running smoothly. 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. - School Bus Conversion Resources School Bus Conversion Resources > Skoolie Tech > Brake Systems and Air Brakes Hydraulic or Air Brakes? S6.10 Vehicle position and wheel lockup restrictions. trailer Initial brake temperatures before brake applications for subsequent stops are those occurring at the distance intervals. On vehicles with brake power units, disconnect the primary source of power. 0000000954 00000 n Comments are moderated and may not appear for 24 hours or more. endstream endobj 7 0 obj<> endobj 9 0 obj<> endobj 10 0 obj<>/ProcSet[/PDF/Text]/ExtGState<>>> endobj 11 0 obj<> endobj 12 0 obj<> endobj 13 0 obj<>stream When checking for hydraulic leaks in the brake system you should pump the foot pedal ____ times then hold it down A. S5.1.3.1 The service brakes on a vehicle equipped with one or more brake power assist units or brake power units, with one such unit inoperative and depleted of all reserve capability, shall be capable of stopping a vehicle from 60 mph within the corresponding distance specified in column IV of table II. pressure to operate the bus. Then, for a vehicle with a GVWR of 10,000 pounds or less, make four stops from 80 mph if the speed attainable in 2 miles is not less than 84 mph. c. Test the bus a second time to make sure the bus stops properly. Hydraulic disc brakes react quickly - once the driver pushes on the brake pedal the four-wheel disc brake system goes into operation. 0000000778 00000 n There should be no more than 3 psi of air loss. xb````` to 200 F. The service brakes shall be capable of stopping each vehicle in a water recovery test, as specified below. Also, if the air system fails, the default is brakes applied, hydraulic brakes, not so much. All mechanical components of the braking system shall be intact and functional. 0000001241 00000 n Record the maximum control force for each stop. S7.10 Service brake system - inoperative brake power unit or brake power assist unit test. Foot or service brakes distance shall, at all times, be . 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. The caliper attaches to and slides within an anchor plate or bracket. formatting. 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 parking brake tests for any vehicle on different grades, in different directions, and for different loads may be conducted in any order. Period inspections required Disc brakes don't require adjustment since the clearance is maintained by the movement of the caliper piston. 0000000732 00000 n If its low, that could indicate a leak as well. The wind velocity is zero. The first test is a pressure check. Listen for any possible leaks. This questions appears in the following tests: Colorado Double District Of Columbia Class A Knowledge Test Illinois Passenger Each vehicle shall be capable of completing all performance requirements of S5 without -. are closed except as required for instrumentation purposes. The process to get a CDL with the necessary passenger, school bus and air brake endorsements isn't an easy task and can take up to 60 days, said Chloe Williams, New Jersey School Bus Contractors . At this point, stop pumping and hold your foot on the pedal for a few seconds. Determine whether the brake system indicator lamp is activated when the RBS is disconnected. Drive for 1.5 mi at 40 mph after the last snub and immediately follow the recovery procedure specified in S7.11.3.2. If the power assist fail on a hydraulic brake system A. you will NOT be able to stop the bus B. A master cylinder shall have a reservoir compartment for each service brake subsystem serviced by the master cylinder. Repeat S7.7.1 or S7.7.2 as applicable except with the vehicle at lightly loaded vehicles weight or at manufacturer's option, for a vehicle with GVWR greater than 10,000 pounds, at lightly loaded vehicle weight plus not more than an additional 1,000 pounds for a roll bar structure on the vehicle. There are a few reasons. Are their school bus drivers that prefer one over the other? Fuel Tank/Cap - tank secure, cap tight, no leaks . 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. How many seconds should you apply pressure to the brake pedal while doing a hydraulic brake check? endstream endobj 57 0 obj<> endobj 59 0 obj<> endobj 60 0 obj<>/ProcSet[/PDF/Text]/ExtGState<>>> endobj 61 0 obj<> endobj 62 0 obj<> endobj 63 0 obj<> endobj 64 0 obj<> endobj 65 0 obj<> endobj 66 0 obj<> endobj 67 0 obj<>stream Step on the service brake to make sure the bus doesn't pull to either side. Some have air brakes but most operators have hydraulic.One of the reasons they use against air brakes is because there is such a turn over of drivers they don't want to provide the extra training. (b) In the case of a vehicle with a GVWR greater than 4,536 kilograms (10,000 pounds), with a force applied to the control not to exceed 150 pounds for a foot-operated system and 125 pounds for a hand-operated system. This will tell you how much force the system is capable of generating. 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. Microsoft Edge, Google Chrome, Mozilla Firefox, or Safari. Start your practice test now. Step on the brake and hold the pedal down for one minute. YOU must set the parking brake immediately C. your service brakes will still work, using extra leg power 17. Vehicles with air brakes may use either drum or disc type components. S7.4.1.1 Burnish. 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. Tail Lights/Brake Lights - clean, not missing or broken . A separate drafting site It keeps kids more active. S7.11.2.1 Vehicles with GVWR of 10,000 pounds or less. This members-only test covers must-know topics including medical certificate renewal, preventing brake fade, and more. 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. OEM-specified brake lining and pads are recommended when replacement is necessary. Make six stops from 60 mph with vehicle at lightly vehicle weight, or at the manufacturer's option for a vehicle with GVWR greater than 10,000 pounds, at lightly loaded vehicle weight plus not more than an additional 1,000 pounds for a roll bar structure on the vehicle. Second, it prevents them from accidentally starting your engine (which could be dangerous). (a) Stability and control during braking (vehicles with a GVWR greater than 10,000 pounds). Repeat S7.4, except make 35 burnish stops or snubs. bluebirdvision S7.16 Service brake system - water recovery test. (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. S6.2.5 For tests conducted in neutral, the operator of an EV with no neutral position (or other means such as a clutch for disconnecting the drive train from the propulsion motor(s)) does not apply any electromotive force to the propulsion motor(s). The squeaking is the air escaping after braking and the ppssss sound is the automatic bypass safety valves at work, ensuring the air pressure remains at the correct level. (b) The parking mechanism must be engaged before the ignition key can be removed. Periodic adjustment to manufacturer specifications is required. The secure and easy all-access connection to your content. Great prices on 1009 aftermarket and OEM GMC C6500 Topkick auto parts. The performance requirements of S5 shall be met under the following conditions. Make six stops each from 60 mph, to achieve the average deceleration for each stop as specified in table III. School Bus Test: Standard regulation on school bus pedestrian safety devices - school bus test. 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. 0000002264 00000 n Make 500 snubs between 40 mph and 20 mph at a deceleration rate of 10 f.p.s.p.s. If they are freezing up, your air dryer is not working correctly. 0000000516 00000 n View the most recent official publication: These links go to the official, published CFR, which is updated annually. Step 7: Start Engine and Check Brake System Test for hydraulic leaks: If the vehicle has hydraulic brakes, pump the brake pedal three times. For vehicles with a GVWR of 10,000 pounds or less, or any school bus, make six stops from 30 mph. Choosing an item from (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. If instrument repair, replacement, or adjustment is necessary, make not more than 10 additional stops or snubs after such repair, replacement, or adjustment. (3) Transmitting those controlling signals to one or more modulators which adjust brake actuating forces in response to those signals. If more than one antilock or variable proportioning brake subsystem is provided, disconnect or render one subsystem inoperative and run as above. Press both air brake valves in, red valve first then yellow in second. S7.9.2 Repeat S7.9.1 for each of the other subsystems. 0 3. I just bought my first School bus and it has air brakes. (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. The service brakes shall be capable of stopping each vehicle in two fade and recovery tests as specified below. 2004 GMC Topkick/Kodiak Service Manual. Restore the system to normal at completion of this test. Please do not provide confidential 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. 2. The cast disc (rotor) is bolted to the hub assembly. 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. Why Hydraulic Brakes Do Not Work If Bubbles of Air Leak into the Liquid? 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. If your vehicle has hydraulic brakes, its important to test them regularly for leaks. Automotive braking systems are obviously very important and must be thoroughly tested prior to production. (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. 1509 (relating to qualifications . Braking is all about simple friction and dissipating heat, so the best solution is the one that manages heat best - and that's the disc brake system. I'll show you my air brakes if you show me yours. 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. The official, published CFR, is updated annually and available below under S5.3.4 When an indicator lamp is activated it may be steady burning or flashing. (b) If a single common indicator is used, the lamp shall display the word Brake. 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. Maintain control force until vehicle has stopped. S7.11.1.1 Vehicles with GVWR of 10,000 lb or less. Burnish stops are conducted on any surface. Beats leaf springs all to hell. With the traction battery pack fully charged, it is capable of approximately an 70 mile range at a constant 45 mile per hour velocity. 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. Linings are assumed adjusted for normal operating clearance in the released position. If you feel unsafe at any time, move to a different location. Don't automatically be fooled by big-rigs use of air brakes. S-cam brakes, on the other hand, require an external slack adjuster. Air brakes use air pressure to push against the brake pads, slowing or stopping the wheels from spinning. Full brake application means a brake application in which the force on the brake pedal reaches 150 pounds within 0.3 seconds from the point of application of force to the brake control. At the completion of the stops specified above, deplete the system of any residual brake power reserve capability. 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. On vehicles with brake power assist units, the unit is charged to maximum prior to start of test. Air Brakes - They just plain Sound Bad-Ass!! "Published Edition". Average the maximum brake control force required for the three snubs. The RBS is operational during all burnishes and all tests, except for the test of a failed RBS. startxref Some people will disagree with me. 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. (b) At vehicle speeds of 10 mph or less, any wheel may lock up for any duration. 1. 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. Check the fluid level in the hydraulic brake reservoir. If air bubbles get into the hydraulic fluid, they can compress when the brake pedal is applied. 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. Allow a braking distance interval of 1 mi. A. will bring you directly to the content. Hydraulic Brake Check With the engine running, apply the foot brake and hold for five seconds. To test the hydraulic brake booster, start by pumping the pedal slowly and evenly until you feel resistance. Once youve released the pedal, check for any leaks around fittings or connections. Test procedure and sequence. Comments that include personal Texas Air Brakes CDL Practice Test. S5.1.6 Spike stops. The CamLaster brake has 2 key design differences over traditional S-cam brakes. (b) For vehicles with a GVWR greater than 10,000 pounds, stability and control during braking tests are conducted on a 500-foot-radius curved roadway with a wet level surface having a peak friction coefficient of 0.55 when measured on a straight or curved section of the curved roadway using an ASTM F2493 standard reference tire, in accordance with ASTM E1337-19 at a speed of 40 mph, with water delivery. 3. If at a snub condition of 40 to 20 mph, the temperature of the hottest brake exceeds 550 F, make the remainder of the 35 brake applications from the snub condition without regard to brake temperature. S7.10.1 Regular procedure. Navigate by entering citations or phrases Each vehicle with electrically-actuated service brakes (brake power unit) shall comply with the requirements of S5.1.3.1 with any single electrical failure in the electrically-actuated service brakes and all other systems intact. 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 actuation system causes displacement of fluid at a volume and pressure required to cause the foundation brake to apply. (a) The service brake system for detachment or fracture of any components, such as brake springs and brake shoes or disc pad facing. Background and more details are available in the S5.1.1.3 In the third effectiveness test the vehicle shall be capable of stopping at lightly loaded vehicle weight from 60 mph within the corresponding distance specified in column III of table II. HWn}W#Xwy76 (Ipj.Z. Start the engine and run at idle speed. 0000001720 00000 n 7, Hydraulic Brake Reservoir Second, use your emergency brake. 41. Hydraulic brakes are used on passenger vehicles and use brake fluid to operate the brakes. Words in addition to those required by Standard No. S5.1.3.4 Brake power assist and brake power units. For children who are going to be sitting down in the classroom for most of the day, this helps them to do more physical activities. This chapter applies to the course of instruction and physical examination for school bus drivers required by 75 Pa.C.S. Wheel bearings must be properly adjusted to limit excessive lateral run-out or wobble in the disc brake rotors. Attain the required deceleration within 1 second and, as a minimum, maintain it for the remainder of the stopping time. Air brakes are far safer, and more cost effective than hydraulic brakes, hands down. (b) For vehicles manufactured on and after September 1, 1999 with GVWRs greater than 10,000 lbs, each message about the existence of a malfunction, as described in S5.3.1(c), shall be stored in the antilock brake system after the ignition switch is turned to the off position and the indicator lamp shall be automatically reactivated when the ignition switch is again turned to the on position. Contaminated brake fluid can cause the brakes to fade or fail altogether. Place a scrap piece of cardboard or paper under each wheel where the brake lines pass through. S5.1.3.2 Brake power assist units. S7.15 Service brake system - fourth effectiveness test. Reservoirs, whether for master cylinders or other type systems, shall have a total minimum capacity equivalent to the fluid displacement resulting when all the wheel cylinders or caliper pistons serviced by the reservoirs move from a new lining, fully retracted position (as adjusted initially to the manufacturer's recommended setting) to a fully worn, fully applied position, as determined in accordance with S7.18(c) of this standard. After leaving the trough, immediately accelerate at a maximum rate to 30 mph without a brake application. The pedal should not move (lose pressure) during those five seconds. S7.4 Service brake system - burnish procedure. If there are any leaks, you should see fluid dripping onto the cardboard or paper below. With vehicle at GVWR, disconnect functional power source, or otherwise render antilock system inoperative. (3) Before or upon application of 25 pounds of control force upon a service brake with a brake power assist unit. Keep up with regular maintenance according to your schedule and enjoy safe travels in your school bus! Stops, other than spike stops, are made without any part of the vehicle leaving the roadway. Explanation To test hydraulic brakes, you should pump the brake pedal three times, then apply firm pressure to the brake pedal and hold for five seconds. 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). Disc brake systems use a two-piston sliding caliper at the steer axle and drive axle; older buses may utilize a single-piston caliper. They last longer and are much more cost effective. Hydraulic or Air Brakes? OEM-standard lubricants are the best choice for this application because they're designed to meet tough duty standards, like school buses. 0000000016 00000 n Steering Hydraulic Leak Test: Thoroughly clean the hydo-boost unit and all hose connections. 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). CDL School Bus Endorsement S Practice Test -3. Control force readings may be terminated when vehicle speed falls to 5 mph. @WXhP|kk=_BW. S6.5 Engine. Accelerate immediately to the initial test speed after each snub. Tire inflation pressure is the pressure recommended by the vehicle manufacturer for the GVWR of the vehicle. Keep the longitudinal axis of the barrier parallel with the longitudinal axis of the vehicle. To drive a vehicle with air brakes, you must pass the air brake component of the Georgia CDL knowledge test. S7.7.3 Lightly loaded vehicle. Service on the single- or twin-piston caliper is essentially the same. Next, firmly apply pressure to the pedal and hold it down for 30 seconds. S6.10.1 For vehicles with a GVWR of 10,000 pounds or less, stops are made with wheel lockup permitted only as follows: (a) At vehicle speeds above 10 mph, there may be controlled wheel lockup on an antilock-equipped axle, and lockup of not more than one wheel per vehicle, uncontrolled by an antilock system. 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.

Merrick Whole Earth Farms Discontinued, Articles H