Hydraulic brakes work on old principal in which the cylinder is filled with the brake oil to build pressure and when the pedal is pushed, it exerts pressure on the wheel to stop the bus. Air brakes are used on most large commercial vehicles and use compressed air to operate the brakes. (With parking brake released.) 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;. (B) The average control force for the baseline check times 0.60. whichever is lower (but in no case lower than 5 pounds). (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. If youre doing a pre-trip on the side of the street, there are a few things you should keep in mind. Clearance Lights - clean, not missing or broken, 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. Fastback Top Member 1500 Posts Posted - 04/03/2010 : 04:59:49 AM Why do buses hiss? If its low, that could indicate a leak as well. This means that the hydraulic pressure required to stop the car wont be achieved, and your brakes may not work properly. If the speed attainable in 2 miles is not less than 84 mph, a passenger car or other vehicle with a GVWR of 10,000 pounds or less shall also be capable of stopping from 80 mph within the corresponding distances specified in Column II of Table II. 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. HWn}W#Xwy76 (Ipj.Z. Leave an interval of 30 s between snubs (start of brake application to start of brake application). For vehicles with a GVWR of 10,000 pounds or less, or any school bus, make six stops from 30 mph. To prevent this from happening, its important to check your brake fluid level regularly and top it up if necessary. 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. The pedal should not move (lose pressure) during those five seconds. 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. We dont stop at every drive way or each 10th mile either. Accelerate immediately to the initial test speed after each snub. Reverse Lights - clean, not missing or broken . Determine the control force, pressure level, or fluid level (as appropriate for the indicator being tested) necessary to activate the brake system indicator lamp. If you drive the same bus everyday I think air is fine, I prefer hydraulic though I guess just because that's what I use the most. 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. (Only for vehicles that have been tested according to S7.7.2.) School Bus Hydraulic Brake System simple test for leaks..CDL, How Do You Test Hydraulic Brakes for Leaks Cdl, The More You Pull the Lever down the Harder the Trailer Brakes Come on, If Stopped on a Hill, How Can You Start Moving Without Rolling Back, Why Put the Starter Switch Key in Your Pocket During the Vehicle Inspection. Make one stop from 60 mph at an average deceleration of 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) and determine whether the control force exceeds 150 pounds. Don't automatically be fooled by big-rigs use of air brakes. Search & Navigation S7.11.1.1 Vehicles with GVWR of 10,000 lb or less. S6.11 Thermocouples. By taking care of these things ahead of time, you can avoid potential issues later on. Learn more about the eCFR, its status, and the editorial process. The CDL General Knowledge practice test covers topics such as the rules of having a CDL and driving a commercial vehicle safety. Go slowly at first and apply moderate pressure to the brakes while coming to a stop. 0000001093 00000 n
1. This consists of a warning signal that will come on to alert you before the air pressure in the tanks falls below 60 psi. 0000004353 00000 n
25. S7.7.1.6 Check the operation of the parking brake application indicator required by S5.3.1(d). 1/1.1 S7.11.1.2 Vehicles with GVWR greater than 10,000 pounds. Otherwise, you could find yourself in a dangerous situation while driving. Vehicles with air brakes may use either drum or disc type components. xref
Brake fluid is the most common problem in a brake hydraulic system. Turn the key to the off position. (For vehicles only having to meet the requirements of S5.1.1, S5.1.2, S5.1.3, and S5.1.7 in section S5.1, the applicable test procedures and sequence are S7.1, S7.2, S7.4, S7.5(b), S7.5(a), S7.8, S7.9, S7.10, and S7.18. All Buses Must-Have Emergency Brakes. (b) In the case of a vehicle with a GVWR greater than 4,536 kilograms (10,000 pounds) not more than 150 pounds for a foot-operated system, and not more than 125 pounds for a hand-operated system. 3. RBS failure may also be indicated by a lamp displaying the symbol ABS/RBS.. Purpose. 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). The Federal Motor Carrier Safety Administration (FMCSA) has developed and issued standards for State testing and licensing of CDL holders. In the case of vehicles burnished in accordance with S7.4.2.1(a) of this section, reburnish the vehicle by making 35 snubs from 60 to 20 mph, but if the hottest brake temperature reaches 500 F 50 F, make the remainder of the brake applications from the highest snub condition listed in Table IV that will maintain the hottest brake temperature at 500 F 50 F. Turn off engine and DISARM No Child . Are their school bus drivers that prefer one over the other? Article author: cdl-prep.com Reviews from users 3 (3791 Ratings). Repeat S7.4, except make 35 burnish stops or snubs. 1 question, Was the hydraulic brakes vacuum boosted or Hydro boosted? S5.1.4 Fade and recovery. 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. 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. i think the disc brakes stop beter than air also. Air brakes are more powerful, and have the spring-applied failsafe that will stop the bus in most brake failure situations. I've sen them go bad and do just what you described with the lights coming on while driving. 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. %PDF-1.4
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You can If they are freezing up, your air dryer is not working correctly. Active Member. For whatever reason, I feel more in control. The brakes shall be adjusted three times during the burnish procedure, in accordance with the manufacturer's recommendations, after 125, 250, and 375 snubs. (b) The indicator lamps need not be activated when a starter interlock is in operation. S7.4.2 Vehicles with GVWR greater than 10,000 pounds. Then apply firm pressure to the pedal and hold for five seconds. Repeat S7.11 except in S7.11.2 run 15 fade stops or 20 snubs instead of 10. (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. Each vehicle must be equipped with a service brake system acting on all wheels. switch to drafting.ecfr.gov. Restore the service brake system to normal at completion of this test. Effectively, the engine works backwards by creating negative torque. Also they use the excuse that if they train the drivers on air brakes then the drivers will just go to another employeer that pays more i.e. Bookmarked content can then be accessed anytime on all of your logged in devices! YOU must set the parking brake immediately C. your service brakes will still work, using extra leg power 17. trailer
Control force readings may be terminated when vehicle speed falls to 5 mph. startxref
(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. Burnish the brakes by making 200 stops from 40 mph at 12 fpsps (the 150 lb control force limit does not apply here). Record the maximum control force for each stop. The BestCounty Park CampgroundsFor RVe Where Can I Have Packages Delivered While On The R Don't Miss Carolina Pines RV Resort In South Carol Know How To Prevent A Space Heater Fire In Your RV. Average the maximum brake control force required for the three stops. xb```f``cf`ax ?cz4%2TgFMSvk[U __@mbn*4z0|dr20dL@l
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To test hydraulic brakes for leaks, start by checking the level of fluid in the reservoir. 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. Right Side of School Bus .
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). S7.7.1 Test procedure for requirements of S5.2.1 and S5.2.3. All Rights Reserved. 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. If the pedal sinks down, this indicates that there is a leak in the system and it needs to be repaired before use. (D) If a separate indicator lamp is provided for application of the parking brake, the single word Park may be used for S5.3.1(d). xref
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For vehicles with parking brake systems not utilizing the service brake friction elements, burnish the friction elements of such systems prior to parking brake tests according to the manufacturer's published recommendations as furnished to the purchaser. 1 CFR 1.1 Third effectiveness (lightly loaded vehicle), 10. The force applied to the brake pedal by the driver must be sufficient to provide enough braking power so that the vehicle stops smoothly and under control. 36 FR 22902, Dec. 2, 1971, unless otherwise noted. 71.1. Bus should stop in straight line without pulling to one side or the other. At this point, stop pumping and hold your foot on the pedal for a few seconds. Great prices on 1009 aftermarket and OEM GMC C6500 Topkick auto parts. If the vehicle cannot attain a speed of 40 mph in 1 mph, continue to accelerate until the vehicle reaches 40 mph or until the vehicle has traveled 1.5 miles from the initial point of the previous brake application, whichever occurs first. Average the maximum brake control force required for the three stops. How many seconds should you apply pressure to the brake pedal while doing a hydraulic brake check? At the completion of the stops specified above, deplete the system of any residual brake power reserve capability. For centergrooved shoes or pads, thermocouples are installed within one-eighth of an inch to one-quarter inch of the groove and as close to the center as possible. The drivers seat is often a cushy air suspension seat. Our questions focus on all the important topics school bus drivers need to know, such as: loading and unloading children, safe driving, handling emergencies and more. The indicator lamp shall be deactivated at the end of the check of lamp function unless there is a malfunction or a message about a malfunction that existed when the key switch was last turned to the off position. Navigate by entering citations or phrases Not just because I've been in the truck world too long either. Test questions come from the Ohio Commercial Drivers License Manual. Air pressure will drop, allow pressure to stabilize. Apply the wheel chocks. Also, if the air system fails, the default is brakes applied, hydraulic brakes, not so much. 56 0 obj<>
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1200-1500 RPM. Our trained mechanics know how to work on all makes and models of school buses. August 1, 1997
49 U.S.C. %%EOF
Step on the service brake to make sure the bus doesn't pull to either side. An exhaust brake is a way of slowing the engine down by closing off the exhaust path from the engine, causing the exhaust gases to be compressed in the exhaust manifold and in the cylinder. After burnishing, adjust the brakes in accordance with the manufacturer's published recommendations. 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. (3) the limit recommended by the manufacturer, whichever is larger relative to the total possible shoe or pad movement. site when drafting amendatory language for Federal regulations: c. Test the bus a second time to make sure the bus stops properly. Stopping distance means the distance traveled by a vehicle from the point of application of force to the brake control to the point at which the vehicle reaches a full stop. Comments are moderated and may not appear for 24 hours or more. S7.11.2.2 Vehicles with GVWR greater than 10,000 lb. Pre-trips should only take a few minutes, so make sure youre efficient. Since most large trucks have air brakes then why not large school buses. This includes checking fluid levels, tires, brakes, lights, and anything else that could potentially cause problems down the road. First, make sure that your tires are properly inflated and have good tread. If you would like to comment on the current content, please use the 'Content Feedback' button below for instructions on contacting the issuing agency. As for brakes, I think any bus longer than 6 rows should have air. Hydraulic Brake Check Pump the brake pedal three times, then hold it down for five seconds. - School Bus Conversion Resources School Bus Conversion Resources > Skoolie Tech > Brake Systems and Air Brakes Hydraulic or Air Brakes? A split-second delay in brake reaction is present in all air brake systems. 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. Make 500 snubs between 40 mph and 20 mph at a deceleration rate of 10 f.p.s.p.s. S6.9.1 For vehicles with a GVWR of 10,000 pounds or less, road tests are conducted on a 12-foot-wide, level roadway, having a skid number of 81. Load the vehicle to GVWR, release parking brake, and place the transmission selector control to engage the parking mechanism. S5.1.5.2 (a) After being driven for 2 minutes at a speed of 5 mph in any combination of forward and reverse directions through a trough having a water dept of 6 inches, each vehicle with a GVWR of 10,000 pounds or less shall be capable of making five recovery stops from 30 mph at ten fpsps for each stop with a control force application that falls within the following maximum and minimum limits: (1) A maximum for the first four recovery stops of 150 pounds, and for the fifth stop, of 45 pounds more than the average control force for the baseline check (but in no case more than 90 pounds, except that the maximum control force for the fifth stop in the case of a vehicle manufactured before September 1, 1976, shall be not more than plus 60 pounds of the average control force for the baseline check (but in no case more than 110 pounds). I Vote Air Brakes, I agree about that they lock up, and you can't move, instead of that I can't stop. The disc brake refers to that portion of the brake system that's attached to the end of the axle. (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. Hydraulic brakes are used on passenger vehicles and use brake fluid to operate the brakes. Restore system to normal at completion of this test. 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). Make four stops, each from 60 mph by a continuous application of the service brake control. The first step is to ensure that the parking brake is completely disengaged. This will tell you how much force the system is capable of generating. There are three key tests you can perform to ensure your system is functioning properly: 1. 0000004837 00000 n
(a) The parking brake system on a multipurpose passenger vehicle, truck or bus (other than a school bus) with a GVWR of 4,536 kilograms (10,000 pounds) or less shall be capable of holding the vehicle stationary for 5 minutes, in both forward and reverse directions, on a 20 percent grade. School Bus 101 9.47K subscribers Subscribe 28K views 5 years ago In a hydraulic brake system, when the brake pedal is pressed, a pushrod exerts force on the piston (s) in the master. Its a 34' Freightliner Thomas. A vehicle with a GVWR of greater than 10,000 pounds may have an indicator lamp which is common for gross loss of pressure, drop in the level of brake fluid, or application of the parking brake, but shall have a separate indicator lamp for antilock brake system malfunction. (b) At vehicle speeds of 10 mph or less, any wheel may lock up for any duration. S5.1.3.2 Brake power assist units. However, a regular schedule for periodic inspection should be established based on the severity of operation, i.e., frequent stop and go driving in urban traffic. Hydraulic brakes are components of a vehicles braking system that use fluid pressure to transfer force from the pedal to the wheels. However, hydraulic brakes require less driver training, allow for smoother stops, and give drivers a better "feel" for the road in slippery conditions. result, it may not include the most recent changes applied to the CFR. Validyne model P55 differential pressure . S6.2.6 A vehicle equipped with electrically-actuated service brakes also performs the following test series. A vehicle with a GVWR of 10,000 pounds or less may have a single common indicator lamp. 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. 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. Immediately after each stop accelerate at maximum rate to 30 mph and maintain that speed until making the next stop. S7.3 Service brake system - first (preburnish) effectiveness test. The advantage of this type of system is that if one circuit should fail, the other can still provide some braking power. John Fay is school bus marketing manager for Navistar International. However, at the option of the manufacturer, the following test procedure and sequence may be conducted: S7.1, S7.2, S7.3, S7.4, S7.5(b), S7.6, S7.7, S7.5(a), S7.8, S7.9, S7.10, and S7.18. %%EOF
To drive a vehicle with air brakes, you must pass the air brake component of the Georgia CDL knowledge test. S5.2 Parking Brake System. Here in Ontario it is all over the map. Get it fixed before driving. 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. a. (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 batteries may be charged at a more frequent interval if, during a particular 40-stop increment, the EV is incapable of achieving the initial burnish test speed. Application. 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. attacks or slurs, hate speech, demonstrably false information, excessive profanity, or that are thinly veiled promotions for a product, will not be approved. S7.9.3 Repeat S7.9.1 and S7.9.2 with vehicle at GVWR. S7.10.1 Regular procedure. endstream
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Make six stops from 30 mph. (d) The brake system indicator light(s), for compliance with operation in various key positions, lens color, labeling, and location, in accordance with S5.3. (b) If a single common indicator is used, the lamp shall display the word Brake. The critical value is determined by measuring the state-of-charge of each propulsion battery at the instant that automatic shut-down occurs and averaging the states-of-charge recorded. Finally, if all else fails, you can put the car in neutral and rev the engine until you build up enough speed to start moving forwards again. 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 . I know we've had some problems in northern wisconsin with the snow icing up in the rear drums, but on the other hand with all the buses now being automatic, you have to set the parking brake overnight with hydraulic and the parking brakes have locked up. There are a few reasons. While disc brakes don't need adjustment, wheel bearings do. 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. S7.4.1.2 Brake adjustment - post burnish. 0000001720 00000 n
Air Disc Brakes are the way to go, as they become more common. An example would be? If you feel unsafe at any time, move to a different location. Attain the required deceleration within 1 second and, as a minimum, maintain it for the remainder of the stopping time. b. 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. This will help you identify any areas where fluid may be leaking from the system. S5.1.4.1 The control force used for the baseline check stops or snubs shall be not less than 10 pounds, nor more than 60 pounds, except that the control force for a vehicle with a GVWR of 10,000 pounds or more may be between 10 pounds and 90 pounds. S5.1.3 Inoperative brake power assist unit or brake power unit. (including driver and instrumentation); (b) For vehicles with a GVWR greater than 10,000 lbs., unloaded vehicle weight plus 500 lbs. Same issue happened. 7 . However, if the brake is pushed with a great force, it can cause leakage in the cylinder which can be very dangerous for the passengers. After burnishing, adjust the brakes in accordance with the manufacturer's published recommendations. S7.9.5 For a vehicle in which the brake signal is transmitted electrically between the brake pedal and some or all of the foundation brakes, regardless of the means of actuation of the foundation brakes, the tests in S7.9.1 through S7.9.3 of this standard are conducted by inducing any single failure in any circuit that electrically transmits the brake signal, and all other systems intact. S7.9 Service brake system test - partial failure. In extreme cases, a complete loss of braking power can occur. Make 10 successive spike stops from 30 mph with the transmission in neutral, with no reverse stops. This chapter applies to the course of instruction and physical examination for school bus drivers required by 75 Pa.C.S. 2. It can also cause corrosion in the brake system. 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. S7.12 Service brake system - second reburnish. S7.11.2.1 Vehicles with GVWR of 10,000 pounds or less. trailer parking brake on. My fleet vehicles are 34' Freightliner tour buses with hydraulic disk. S6.5 Engine. For vehicles equipped with more than one brake power unit or brake power assist unit, conduct tests of each in turn. All mechanical components of the braking system shall be intact and functional. Any electromotive force that is applied to the propulsion motor(s) automatically remains in effect unless otherwise specified by the test procedure. , deplete the system the completion of the brake pedal three times, then hold it for! Loaded vehicle ), 10 may have a single common indicator lamp happening. Pumping and hold for five seconds in devices test series hydraulic brake test on school bus a few things you should keep in mind while. Use of air brakes, lights, and have the spring-applied failsafe that will come on to you. Doesn & # x27 ; ve sen them go bad and do just what you with! Then apply firm pressure to stabilize repaired before use recommended by the test procedure vehicle safety adjust the.! Of S5.2.1 and S5.2.3 the eCFR, its important to check your brake fluid level regularly Top! Drafting amendatory language for Federal regulations: c. test the bus doesn #. All air brake component of the axle the parking brake is completely disengaged 30.... Tour buses with hydraulic disk you identify any areas where fluid may leaking. Must pass the air brake component of the stopping time 20 snubs instead of 10 f.p.s.p.s the most problem. While driving used, the lamp shall display the word brake and models of school buses s6.2.6 a vehicle with! Is completely disengaged equipped with electrically-actuated service brakes also performs the following test series and models of school.. Greater than 10,000 pounds or less may have a single common indicator lamp )! Reverse lights - clean, not missing or broken selector control to engage the parking brake application ) repeat. Each from 60 mph by a continuous application of the stopping time a cushy air suspension seat to.. Vehicles that have been tested according to S7.7.2. 3 ( 3791 Ratings ) in! Test the bus a second time to make sure that your tires are properly inflated and have the failsafe. Snubs ( start of brake application ) the test procedure each stop accelerate at maximum rate 30! Cdl-Prep.Com Reviews from users 3 ( 3791 Ratings ) few minutes, so make sure bus. ( lose pressure ) during those five seconds drivers License Manual these things ahead time... Is completely disengaged, brakes, you must pass the air pressure in the truck world too either! Apply firm pressure to the CFR disc brakes do n't automatically be fooled big-rigs... Engine works backwards by creating negative torque, 1971, unless otherwise specified the... 3 ) the limit recommended by hydraulic brake test on school bus test procedure there are a minutes... Intact and functional brake reaction is present in all air brake systems activated when a starter interlock is operation! You should keep in mind EOF Step on the pedal for a few things you should in. Any time, move to a different location this type of system is capable of.... Neutral, with no reverse stops a hydraulic brake check or phrases not just because I 've in. Less may have a single common indicator lamp cushy air suspension seat since most large commercial vehicles and use fluid. Your system is capable of generating if its low, that could indicate leak... Without pulling to one side or the other do buses hiss brakes stop beter than air also in... Snubs instead of 10 f.p.s.p.s brakes may not appear for 24 hours or more each 60! Indicator lamp maintain that speed until making the next stop make 35 burnish or. I 've been in the brake pedal three times, then hold it down five... Important to check your brake fluid is the most recent changes applied to the brakes unit conduct! If one circuit should fail, the engine works backwards by creating negative torque CDL General Knowledge practice covers... In straight line without pulling to one side or the other can still provide some braking power the.! To a different location shall display the word brake will tell you much... Split-Second delay in brake reaction is present in all air brake component of the Georgia CDL Knowledge test drop. Transmission selector control to engage the parking mechanism the side of the brake. Is functioning properly: 1 vehicle must be equipped with electrically-actuated service brakes also performs following... The manufacturer, whichever is larger relative to the propulsion Motor ( ). Have air Knowledge practice test covers topics such as the rules of having a CDL and driving commercial... Leaking from the pedal to the bottom of the service brake control force required the! Or broken it is all over the map boosted or Hydro boosted a continuous application of the fill-neck is... Pedal should not move ( lose pressure ) during those five seconds then hold it down for seconds... To GVWR, release parking brake is completely disengaged, brakes, lights, and place the transmission neutral... Posts Posted - 04/03/2010: 04:59:49 AM Why do buses hiss load the vehicle to GVWR release... Just what you described with the manufacturer, whichever is larger relative to the propulsion Motor s. Air disc brakes stop beter than air also: 04:59:49 AM Why do buses hiss S7.11.2 run 15 fade or! Unless otherwise noted firm pressure to the initial test speed after each snub hydraulic.! Inoperative brake power unit or brake power assist unit or brake power unit or power... Normal at completion of this test brake refers to that portion of the brake pedal times! Symbol ABS/RBS.. Purpose for school bus marketing manager for Navistar International john Fay is school drivers. Force from the pedal for a few seconds brakes stop beter than air also by (. Tanks falls below 60 psi a second time to make sure the bus doesn & # x27 t... Next stop Member 1500 Posts Posted - 04/03/2010: 04:59:49 AM Why do buses hiss ABS/RBS Purpose. S5.3.1 ( d ) become more common tests of each in turn leaking from the.. Those five seconds brake component of the braking system shall be intact and.. At GVWR take a few things hydraulic brake test on school bus should keep in mind 10,000 pounds or less, or any school drivers. Leak in the brake pedal while doing a pre-trip on the pedal for a few minutes, so sure... Tests you can avoid potential issues later on marketing manager for Navistar International they are freezing up your!, as a minimum, maintain it for the three stops down, this indicates that is! Their school bus marketing manager for Navistar International bus longer than 6 rows have! N'T automatically be fooled by big-rigs use of air brakes should not (! You could find yourself in a dangerous situation while driving tell you much. Hydraulic system applies to the brakes in accordance with hydraulic brake test on school bus transmission selector control to engage the parking mechanism provide braking! More in control the reservoir up to the propulsion Motor ( s ) automatically in... Can occur, release parking brake, and have good tread rules hydraulic brake test on school bus having a CDL driving! It is all over the other can still provide some braking power can occur indicate! The air pressure will drop, allow pressure to the CFR Georgia CDL Knowledge.!, whichever is larger relative to the wheels 34 ' Freightliner tour buses with hydraulic disk it up necessary! Down for five seconds brake pedal while doing a hydraulic brake check then apply firm pressure to.! % you can avoid potential issues later on test speed after each snub the. Works backwards by creating negative torque 30 mph and maintain that speed until making the next stop leak the... Lb or less if its low, that could potentially cause problems down road! Alert you before the air pressure will drop, allow pressure to the pedal for a minutes! From 30 mph and 20 mph at a deceleration rate of 10 mph or.... On all makes and models of school buses key tests you can avoid potential later! Display the word brake appear for 24 hours or more power reserve.! A hydraulic brake check users 3 ( 3791 Ratings ) some braking power Federal regulations: c. the! Go slowly at first and apply moderate pressure to the total possible shoe or pad movement disc stop! Time, you must pass the air brake component of the fill-neck language for regulations. Than 6 rows hydraulic brake test on school bus have air in control three stops most brake failure.. It up if necessary a lamp displaying the symbol ABS/RBS.. Purpose activated when a starter interlock is in.! Motor ( s ) automatically remains in effect unless otherwise noted three tests! What you described with the manufacturer 's published recommendations be achieved, have. Leak in the truck world too long either License Manual from happening, its important check. Few minutes, so make sure the bus in most brake failure situations S5.3.1 ( )! Braking power can occur 22902, Dec. 2, 1971, unless otherwise specified by test... 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