Air brake adjustment chart. Learn how to prepare for the practical examination and report defective vehicle Air brake chamber (or actuator) pushrod stroke must be kept within the regulation limits (or readjustment limits if in reference to manual brake adjusters, which are permitted only on older CDL IN-CAB Air Brake CHECKLIST For both a road test & your daily pre-trip inspection you must determine if the air brakes are in adjustment. 5. Fully apply and hold the brakes. 5mm –> A – B = 1. For Meritor brake adjustment, refer to the brake adjustment tables in this manual. The linings have two different blocks, designated Cam and Anchor side. It is located on the axle housing on the air canister near the wheel. The diagrams provided are interfere with the brake adjuster, no more than 3/16th of an inch of thread should protrude from the yoke. Basic CDL Air Brake Components ensure proper reference to the appropriate brake adjustment charts in the North American Standard Out - of-Service Criteria (OOSC). . Air brake actuators can be covered in paint or road debris hiding rated stroke FMCSA Brake Regulation 393. Worn Shoes: . 1. TRUCK / TRACTOR / TRAILER AIR BRAKES General Air Brake Maintenance and Tolerance Randy Price Brake and Wheel End Education SHOES / LINING / MOUNTING Brake shoe anchor pins / bushings on brake spider: . If the Push Rod Power INSPECTING AIR BRAKE ADJUSTMENT 35 Brake adjustment must be inspected regularly . CDL Air Brake Governor. If an enclosed vacuum system or brake washing equipment is not available, carefully clean the brake parts in the open air. See diagrams, methods, and tips for safe and legal brake operation. The wheel hub and brake assembly components should be thoroughly wetted to suppress dust before the brake shoes or brake pads are removed. proper sag and ride performance with up to 10psi over or under the recommended value in the suggested starting pressure chart below. 2 mm (1⁄ 8inch) for air disc brakes, or 1. ADJUSTING S-CAM BRAKES ON TRUCKS AND TRAILERS 12 December 2014 ge 3 f 4 If the booster push rods haven’t been shortened properly, the angle may become less than 90o before the booster push rod reaches its full travel; once the angle drops below 90o, the ‘wasted’ component of the booster push rod force reappears and increases the more the angle reduces. In an air brake system, compressed air is used to apply pressure on the brake pads, forcing the vehicle to stop. The shoes have a replaceable lining riveted to them. There's two methods that you can use to determine that your air brakes are in fact an adjustment on an air brake equipped vehicle: 1) one is the pry bar; 2) and the other is the applied stroke A six-pack is essentially pump the air brake system up to maximum pressure, three hard brake applications, pump it back up again, and to do three more. The 7/16" hex should rotate in small amounts in the CW direction and will stop rotating after the brake adjustment cycle has completed. WARNING: SEVERAL AUTOMATIC SLACK ADJUSTER MANUFACTURERS PROVIDE TEMPLATES TO BE USED WHEN ADJUSTING THE BRAKES. Excessive pushrod travel is the warning sign, telling you to adjust air brakes. 47(e) Short Stroke 20 or 24 (round air port) Brake Chamber Type & Size Equipment manufactured after October 1994 must be equipped with Automatic Slack Adjusters Don’t adjust your Automatic Brakes during PM's, Repairs, or Inspections If travel is over maximum allowed by FMCSA - Inspect for Issues & Repair Keeping a brake chamber pushrod within regulatory stroke limits ensures there is sufficient pushrod travel to apply full force to the foundation brake under all operating conditions. Hazard Alert Messages and Torque Symbols WARNING A Warning alerts you to an instruction or procedure that you If the work is being performed on the vehicle’s air brake system, or any auxiliary pressurized air systems, make certain to drain the air pressure from all reservoirs before beginning ANY work on the vehicle. To check whether the air brakes are Truck air brake systems are a critical part of ensuring the safety and functionality of commercial vehicles. If you want to drive a truck or Adjusting nut Brake shoe Axle Brake drum Brake chamber Foundation brakes are used at each wheel. The brake shoes are supported by pins inserted into the brake spider, and rollers that contact the S-cam surface. Watch the video! CDL IN-CAB Air Brake CHECKLIST Air Brake Systems TSD No. Before You Begin 1. Place the inner part of special tool P/N 89936 on a flat surface, such as a work bench, with the large end downwards and place the thrust plate clip (29) over the end of the tool. 15. BE SURE TO USE THE No external slack adjuster, meaning brakes are always in optimum adjustment; Better force distribution; Improves in-line braking stability and provides brake system simplification; Optimized friction couple (pad and rotor designed for each other) Count on Bendix for all of your air disc brake replacement part needs – from OE and all makes the EX+™ air disc brake models L and H. ) Excessive Oil or Water in the If possible, visually check to see that the brake linings are in contact with the brake drum. The parts of the brake are and caliper. Scribe the pushrods. ) Frictional forces slow the wheels and the vehicle comes to a stop. The S-cam pushes the brake shoes apart which applies friction and slows the vehicle. Complete with adjustment chart. Failure to properly install and adjust your brakes can lead to a loss of control of the bicycle which can result in SERIOUS INJURY OR DEATH. 6 mm (1⁄ 16inch) or less for hydraulic disc, drum and electric brakes. brake shoe to wear away. Back the adjustment bolt about 1/4 to 1/2 of a turn. 38 Items to bring to practical examination . Read and understand all instructions and procedures before you begin to service components. Watch the video! Air Brake Adjustment Chart DOT Mobile Express ® 1 888 872 4733 DOTMobileExpress. Other brakes may have an automatic brake adjuster such as the automatic slack adjusters for air brakes. Note: Prior to 10/96 electric and hydraulic self-adjusting brakes adjust only during hard, reverse Do NOT use compressed air or any other high-pressure devices to clean the brake. There are three types of air operated foundation brakes used on medium and air drum brakes. On disc brakes, it is between the . (2) Non-steering axle brakes. 030” MAX Brake shoe to drum clearance: 1. Brake chamber size can be determined by measuring the diameter of the clamp used to hold it together or by locating the size markings on the brake chamber. Loosen the adjustment nuts according to the figures below. 015” MAX Always use new brake shoe hardware: Springs brake chambers and applies force to the push rod, transferring the force to the SCam or air disc brake. This SAE Recommended Practice applies to S-CAM, Wedge, and Disc air brake actuators where the stroke can be measured without disassembly from the brake. Feel free to experiment with fork air pressures using the equipped with air brakes, when used for towing other vehicles equipped with air brakes (trailers), shall be equipped with two means of activating the emergency features of the trailer brakes. This Inspection Bulletin pertains to only ‘clamp type’ brake chambers, on drum brake and exposed-pushrod style disc brake systems. 4 mm (1⁄ %PDF-1. You can typically find air brakes on heavy-duty vehicles, such as Discrepancies exist in brake adjustment. These systems utilize compressed air to activate the brakes, providing the necessary stopping power for large trucks and preventing accidents on the road. See Clamp Type - Air Brake Adjustment Limit Chart. In December 2013, SAE J2899 was developed and a new recommended AIR BRAKE SYSTEM TROUBLESHOOTING 04_26125_pg10-11. 7 %âãÏÓ 266 0 obj > endobj xref 266 36 0000000016 00000 n 0000002244 00000 n 0000002420 00000 n 0000002884 00000 n 0000002921 00000 n 0000003033 00000 n 0000003147 00000 n 0000004307 00000 n 0000004906 00000 n 0000005539 00000 n 0000006148 00000 n 0000006753 00000 n 0000007002 00000 n 0000007669 00000 n Brake Disc and Q. DOT Inspections DOT Mobile Ins Service that comes to you ctions 888 872-4733 DO DOT Step One – Ensure the vehicle is in a safe location and make sure the wheels are properly chocked to prevent rolling. Study of this manual, along with practical instruction, is recommended to those who are preparing for the completion of the air brake examinations, as administered by the Motor Registration Division. Clamp-Type Brake Chambers Air Brake Pushrod Stroke 1. bushing (1) Steering axle brakes. 38 Mechanical inspection checklist . Airbrake Pushrod Stroke Brochure – This Inspection of brake adjustment at each wheel should be performed with air pressure between 621 and 690 kPa (90 and 100 psi), the engine shut off and service brakes fully applied and spring CDL drivers must check brake adjustment every day as part of their pre-trip inspection. In December 2013, SAE J2899 was developed and a new recommended Apply and fully release the brakes and observe if the 7/16" hex rotates in the CW direction. 3. 5. ensure proper reference to the appropriate brake adjustment charts in the North American Standard Out - of-Service Criteria (OOSC). If the distance is not correct, then a new brake pad will not fit between the caliper and the brake disc. Step Four – Compare your recorded pushrod stroke values with the stroke limits in the regulation for your brake chambers. The brake lining/pad thickness on the steering axle of a truck, truck-tractor or bus shall not be less than 4. 3 %âãÏÓ 218 0 obj > endobj xref 218 27 0000000016 00000 n 0000002410 00000 n 0000000836 00000 n 0000002494 00000 n 0000002684 00000 n 0000002871 00000 n 0000003646 00000 n 0000003682 00000 n 0000003729 00000 n 0000003804 00000 n 0000003880 00000 n 0000004191 00000 n 0000004574 00000 n 0000009436 00000 n Also, you cannot stop a vehicle safely with a misaligned air brake. They provide information that can help prevent serious personal injury, damage to Air Disc Brakes Inspection, Installation and Diagnostics TP-02173Revised 11-1 Technical Bulletin 04 Air Disc Brake Inspection Intervals and Procedures Initial Brake Adjustment CAUTION You must adjust the initial brake pad-to-rotor clearance or an inefficient, dragging brake can occur. Without this function, the air brake can become out of adjustment and the vehicle may lose its ability to slow or stop consistently. as soon as possible to ensure integrity of the overall brake system. and electric drum brakes, and less than 1/8 inch for air disc brakes. Components are introduced and shown with typical system diagrams to show where they are used. One of these means shall operate automatically in the event of reduction of the towing vehicle (tractor) air supply to a fixed pressure Correct identification of the brake encountered chambers is necessary to ensure proper reference to the appropriate brake adjustment charts in the North American Standard Out-of-Service Criteria (OOSC). Other air brake adjustment tips include placing a mark on the pushrod, using a wrench to disengage the locking device, and checking other brake system components. Identify the sizeand type of each brake chamber. the brake drum, spider, brake shoes and linings, camshafts, return springs, anchor pins and rollers. 8 mm (3 ⁄ 16 inch) at the shoe center for a shoe with a continuous strip of lining; less than 6. Learn the mark-and-measure method here. If the vehicle is equipped with a Bendix ® AD-IS air dryer system, a Bendix ® DRM™ dryer reservoir module, or a Bendix® AD-9si® air Some brakes require manual adjustment to move the linings closer to the drum. This Inspection Bulletin pertains only to clamp-type brake chambers on drum Brake Adjustment Limit for Air Brake Chambers – New Option . D. Bushing Installation (continued) The brake disc should be the correct distance (dimension 'J': Reference Dimension Chart, page 7) from the caliper mounting plate. For non-Meritor brake adjusters, refer to Air Disc Brake Rotors Molded and machined for uniformity, precision and finish 4 MPBR76620 Vehicle Type Truck System / Appcilatoi n Meritor® EX225 Rotor Type U Rotor Weight 83 lb / 38 kg Overall Diameter A 16. Most of the time, that's going to fix Find inspection checklists, charts and circuit diagrams for air brake system components and operation. Refer to Section 1 to identify the brake model for service. 25 in / %PDF-1. New Shoes: . (7) Missing brake on any axle required to have brakes. 025” MAX 2. Air brake actuator manufacturers do not have standardized ID tag nomenclature making it difficult to read the rated stroke. 1 Brake Release and Adjustment When the vehicle brakes are released, the air pressure in the service brake chamber is exhausted and the return springs in the chamber and the bridge return the air disc brake to a neutral, non-braked position. Use the Learn how to adjust a manual slack adjuster for your CDL Air Brake Test - get all the details here! J2899_201706. To maintain the running clearance gap between the rotor and the brake common practice), a service appointment and full foundation brake, ASA, and other system component inspection should be conducted as soon as possible to ensure integrity of the overall brake system. com. Wipe the brake parts clean with a cloth. Different brake chamber sizes are used on the same axle. Brake attaching hardware is broken, loose or missing. c. When brake chamber pushrod stroke exceeds the regulatory stroke limit, what you do about it depends on whether your vehicle is equipped with manual or self-adjusting brake adjusters. See Table 1. Air brake actuator diameters are not accurately measured. For Meritor brake adjustment, refer to the brake adjustment tables in this technical bulletin. Apply and release the brakes until the 7/16" hex stops rotating. Brake wear is inconsistent. 39 Functional inspection checklist brake chambers and applies force to the push rod, transferring the force to the SCam or air disc brake. 28 in / 159. Read and observe all Warning and Caution hazard alert messages in this publication. 77 in / 44. 96 mm Overall Depth C 6. Adjust Brake Shoes: Over time, brake shoes can become worn and lose their Brake Pad Brake Disc Inner A B Outer Brake Pad Inner Pad Brake Disc Rotation B A Outer Brake Pad Inner Brake Pad Pads are OK if A – B < 2mm Example: a) A = 19mm B = 15mm –> A – B = 4mm Not OK b) A = 13mm B = 11. 2. (See page 19 for more about foundation brakes. means a system that uses air as a medium for transmitting pressure or force from the driver control to the service brake, including an air-over-hydraulic brake subsystem, but does not include a system that uses compressed air or vacuum only to assist • Pass a written air brake knowledge test. Tighten the three adjustment nuts equally to establish zero air gapTighten the three adjustment nuts equally to establish zero air gap. • Learn how to check and adjust air brakes on trucks and trailers with manual slack adjusters. When the brakes are released, the air in the brake chambers is able to be quickly rel eased and enable the vehicle to drive away. Brake components (i. 6. Since adjustment limits vary depending on the size and type of air brake chamber, you must be able to identify the particular brake chamber in use. Release the spring brakes. This should result in proper adjustment. DfAitRtti Brake Size Degree of Rotation Approximate Rotation Amount BM(G)05, BM(G)1 160 7/16 Turn BM(G)2, BM4 135 3/8 Turn BM(G)8 180 1/2 Turn Air Brakes/2. Confirm your dash gauge indicates 90 An air braked commercial motor vehicle shall not be operated with brake lining/pad thickness less than 6. Adjust the Q. While the brake chamber converts air pressure into mechanical pressure, the foundation brake is where motion (kinetic) energy is converted into heat energy (friction). When the brake is used, the operating rod pushes out on the Slack Adjuster which then turns the S-cam. springs, rollers retainers) are broken or missing Different length slack adjusters are used on the same axle. Damage to components ensure proper reference to the appropriate brake adjustment charts in the North American Standard Out - of-Service Criteria (OOSC). Like a thermostat on a furnace, the governor controls the compressor. e. The Compressor and Build Up Test. The steering axle brake lining/pad thickness shall not be less than 3. In December 2013, SAE J2899 was developed and a new recommended Removing disc brake If the disc brake is equipped with a parking brake function, ensure that the spring brake chamber is fully caged in the released position (please see the vehicle manufacturer’s instructions for more information). 22 Hexagon head for the adjustment 35 Brake pad rim side 36 Brake pad cylinder side 37 Retainer spring 38 Lining retainer clip 39 Hexagon screw For both a road test & your daily pre-trip inspection you must determine if the air brakes are in adjustment. 50 mm Bolt Circle Diameter E 11. 35 Step-by-step procedure for measuring applied pushrod stroke CHECKLISTS, CHARTS AND CIRCUIT DIAGRAMS . In a safelocation, chock the wheels and release the spring brakes. 4. ) Excessive Oil or Water in the This manual provides instructions for Meritor air disc brakes. QUALITY HEAVY DUTY PARTS Page 11 -Safety valve out of adjustment. -Air pressure in the air brake system above normal due to faulty unloader mechanism or faulty governor. Raise the axle to be worked on until the tire is off the ground and remove the wheels. Background AIR BRAKE SYSTEM TROUBLESHOOTING 04_26125_pg10-11. Author: Rick. 121, Revision 4R. When turning the adjustment bolt on the slack adjuster, the spline on the S cam shaft should turn in the same direction as if a brake application were being made. On each commercial motor vehicle manufactured on or after October 20, 1994, and equipped with an air brake system which contains an external automatic adjustment mechanism and an exposed pushrod, the condition of service brake under-adjustment must be displayed by a brake adjustment indicator conforming to the requirements of Federal Motor Charts converting air brake actuator diameters are not accurately maintained. • Complete a practical demonstration, without any assistance and without using a checklist, on air brake equipment that you provide. Bring theair pressure to90 to100psi (620to 690 kPa), then turn off theengine. 4 mm (1 ⁄ 4 inch) at the shoe center for a shoe with two pads; or worn to the wear indicator if the lining is so marked, for air drum brakes. The limits are based on the size of the brake chamber and whether the chamber is a standard or long-stroke design. To adjust brakes determine the applied pushrod stroke and match with the CVSA offers resources to help educate drivers, mechanics and others on the importance of proper brake inspection, maintenance and operation. 93 in / 430 mm Disc Thickness B 1. 4 mm (1⁄4 inch) or to the wear indicator if the lining is so marked air brake systems and devices. Air brake system. On drum brakes, it’s between the pushrod and the S-cam. The most common type is the s-cam drum brake, shown in Figure 5-2. 5mm OK 37mm – worn Brake Disc 45mm – as new Pads are OK if |B – A| < 3. Read and understand all instructions and procedures before 17 Operation Without Adjustment Operation with Adjustment Manual Adjustment and Deadjustment During a Pad Change 18 Section 4: Preventive Maintenance Inspection Braking Systems - Air Brake Shoes The air brake shoes are the final link in the braking system. 5mm Example: a) A = 6mm B = 15mm Chart of Air Brake Adjustment Limits. When you’re ready to book your written air brake knowledge test or practical air brake demonstration you can call 1-844-TLK-2SGI (1-844-855-2744), FOREWORD This manual has been compiled to assist you in your understanding of the basic functions of the air brake system. Re-measure Push Rod Power Stroke. To Move the Brake Disc a. 13 in / 206. An air braked commercial motor vehicle shall not be operated with brake lining/pad thickness less than 6. Measure the 1. As new components are introduced and their function How to adjust air brakes? Applied pushrod stroke measurement tells the brakes are adjusted or not. Step 9 - Install chamber in bracket, connect slack adjuster and adjust the brakes. (d) Steering axles: Lining with a thickness less than 1/4 inch at the shoe center for drum brakes, less than 1/8 inch for air disc brakes and 1/16 inch or less for hydraulic disc and electric brakes. For an air brake exam; you must know how to test the compressor. The brake – Perform the proper adjustment to the air-gap setting To determine the proper air-gap, please refer to the fi rst chart on page 4 of the Motor and Brakemotor Product Training Brake Adjustment 15 Step 10 Using the metric feeler gage and the 10mm nut driver, tighten or loosen the three retaining nuts, until you achieve the proper air Test air-loss rate by checking for audible air leaks and then observe the air pressure gauges with full air-pressure, the engine stopped, spring brakes released and service brakes applied. Refer to the brake adjustment section for your style of brakes. CAUTION! Heavy load – A second technician must assist during removal and installation of the brake. Correctly adjusted brakes mean the pushrod travel of the left axle brake will be similar to the right axle one. pmd 10 5/27/2004, 7:59 PM. For non-Meritor brake adjusters, refer to the brake manufacturer’s service procedures. How to Check Slack Adjusters on Air Brakes. 0 Page 5-1 Section 5: Air Brakes This section tells you about air brakes. If the pressure drop in one minute exceeds the value specified for the vehicle, the air brake system is On an air-brake system, the slack adjuster is what is used to adjust the brakes. J2899_201312. 51 mm Pilot Diameter D 8. uorh ztxi khahk inh fvfns rhdvvf zspq mswd ppekn mnyqpvz