Brakes Inspection Air Brakes Part 2

Transcription

1 Brakes Inspection Air Brakes Part 2 Student/intern information: Name Date Class Vehicle used for this activity: Year Make Model Odometer VIN Learning Objective/Task Check emergency (spring) brake inversion system, if applicable NATEF Reference Number 7-1D9 P-1 Check tractor protection valve. 7-1D10 P-1 Test air pressure build-up time. 7-1D11 P-1 Inspect coupling air lines, holders, and gladhands. 7-1D12 P-1 Check brake chambers and air lines for secure mounting and damage. 7-1D13 P-1 Check and service air drier. 7-1D14 P-1 Inspect and record brake lining/pad condition and thickness. 7-1D15 P-1 Inspect and record condition of brake drums/rotors. 7-1D16 P NATEF Priority Level Time off Time on Total time Recommended Resource Materials CDX Diesel: Preventive Maintenance and Inspection Technical service bulletins, shop manuals, and any other information applicable to the specific vehicle or components you are working on Class notes Materials Required Vehicle Vehicle manufacturer s workshop manual Manufacturer-specific tools, depending on the concern Vehicle lifting equipment, if applicable Diagnostic tools Electrical/electronic testing equipment Measuring equipment Workshop tools Hand tools Some Safety Issues to Consider Diagnosis of this fault may require test driving the vehicle on the school grounds or on a hoist, both of which carry severe risks. Attempt this task only with full permission from your supervisor/instructor and follow all the guidelines exactly. Caution: If you are working in an area where there could be brake dust present (may contain asbestos, which has been determined to cause cancer when inhaled or ingested), wear and use all OSHA-approved asbestos protective/removal equipment. Lifting equipment such as vehicle jacks and stands, vehicle hoists, and engine hoists are important tools that increase productivity and make the job easier. However, they can also cause severe injury or death if used improperly. Make sure you follow the manufacturer s operation procedures. Also make sure you have your supervisor/instructor s permission to use any particular type of lifting equipment. Comply with personal and environmental safety practices associated with clothing; eye protection; hand tools; power equipment; proper ventilation; and the handling, storage, and disposal of chemicals/materials in accordance with federal, state, and local regulations. Always wear the correct protective eyewear and clothing and use the appropriate safety equipment, as well as fender covers, seat protectors, and floor mat protectors. Brakes Inspection Air Brakes Part 2 1

2 Make sure you understand and observe all legislative and personal safety procedures when carrying out practical assignments. If you are unsure of what these are, ask your supervisor/instructor. Performance Standard 0 No exposure: No information or practice provided during the program; complete training required 1 Exposure only: General information provided with no practice time; close supervision needed; additional training required 2 Limited practice: Has practiced job during training program; additional training required to develop skill 3 Moderately skilled: Has performed job independently during training program; limited additional training may be required 4 Skilled: Can perform job independently with no additional training TASK Verify operator s concern, review past maintenance documents, and record condition on appropriate document. 7-1D9 7-1D16 1. Check operation/functionality of the air brake system parking brake. a. Reference the manufacturer s workshop manual for the correct procedure for checking the spring brake inversion system operation. b. Ensure that the air pressure has been completely built up; apply parking brake: Operational air pressure: psi c. Shut the engine down. Time off Time on Total time d. Install an air pressure gauge in the spring brake air line at the brake chamber: Pressure reading: psi e. Release spring brakes from inside the cabin: Air pressure gauge reading: psi f. Apply spring brakes: Air pressure gauge reading: psi g. Remove test air pressure gauge and reconnect spring brake hose. h. Did the spring brake inversion system operate within specifications? 2. Check the tractor protection valve. a. Reference the manufacturer s workshop manual for the correct procedure for checking the tractor protection valve system operation. b. Block and/or hold the vehicle by means other than the air brakes during these tests. c. Drain vehicle reservoirs; ensure that a container(s) is placed under the drain cocks to collect any contaminants. Then close the drain cocks. d. Disconnect vehicle emergency and service hose couplings and connect assembled hose coupling and test gauge in tractor emergency hose coupling. e. Start engine and build up system pressure. Brakes Inspection Air Brakes Part 2 2

3 f. As pressure in the system builds up there should be no pressure reading on the test gauge. When system pressure reaches 30 psi (210 kpa) on the dash gauge, make and hold a foot or hand valve application and observe that no air escapes at the open service hose coupling. g. Observe the air pressure on the test gauge: Test pressure gauge reading: psi h. When the system pressure reaches 40 to 60 psi (280 to 420 kpa), the valve should open and the pressure reading show on the test gauge. Allow the system to build up to 100 psi (700 kpa) and shut off engine. i. With a soap solution, coat the exhaust port of the tractor protection valve. Leakage of a 1 (25mm) bubble in 3 seconds is permissible (175 SCCM). j. Record the leakage rate: Leakage: inches (mm) in seconds k. Remove the test air pressure gauge and reconnect the brake hose. l. Did the tractor protection valve system operate within specifications? 3. Test air pressure build-up time. a. Reference the manufacturer s workshop manual for the correct procedure for checking the air pressure build-up timing. b. Block and/or hold the vehicle by means other than air brakes during these tests. c. Drain vehicle reservoirs; ensure that a container(s) is placed under the drain cocks to collect any contaminants. Then close the drain cocks. d. Pressure gauge reading: psi e. Start time of air build: minutes seconds f. Start engine and build up system pressure. g. Check pressure as system builds up; record pressure when low pressure warning device goes out: Pressure gauge reading: psi Time to build up to shut off low pressure warning device: minutes seconds h. Check pressure as system builds up; record pressure when governor cut-out pressure is reached: Pressure gauge reading: psi Time taken to build up to shut off low pressure warning device: minutes seconds i. Record total time from start of pumping to reach governor cut-out pressure: minutes seconds Brakes Inspection Air Brakes Part 2 3

4 j. Did the air pressure build-up time operate within specifications? 4. Inspect the coupling air lines, holders, and gladhands. a. Following the procedure from the workshop manual, check and inspect the condition and serviceability of the coupling air lines, holders, and gladhands. b. Are the coupling air lines, holders, and gladhands condition serviceable and within specifications? 5. Check brake chambers and air lines for secure mounting and damage. a. Following the procedure from the workshop manual, carry out a visual inspection of the air brake chambers, mounting, and air lines: Serviceable: Need repairs/unserviceable: If unserviceable/need repairs: List the areas and your recommendation(s): 6. Check and service the air drier. a. Following the procedure from the workshop manual, observe all safety precautions listed and carry out the service of the air drier: Serviceable: Need repairs/unserviceable: If unserviceable/need repairs: List the areas and your recommendation(s): 7. Inspect and record the brake lining/pad condition and thickness. With reference to vehicle manufacturer s workshop manual, research the description and operation of the brake system for this vehicle, including the drum brake diagnostic procedure and the wheel assembly and brake drum(s) removal/installation procedures. a. Discuss these findings with your instructor. b. If instructed by your instructor, carry out the inspection procedure. c. Record the following information: Maximum drum diameter: in/mm Maximum drum out-of-round: in/mm Minimum lining thickness (primary): in/mm Minimum lining thickness (secondary): in/mm d. Are these measurements within specifications? Brakes Inspection Air Brakes Part 2 4

5 e. Refit the drum and wheel assembly in accordance with the manufacturer s specifications. f. Ensure that the wheel lug nuts are torqued to the manufacturer s specification and tightening sequence. 8. Inspect and record conditions of brake drum/rotor. With reference to vehicle manufacturer s workshop manual, research the description and operation of the brake system for this vehicle, including the drum brake diagnostic procedure and the wheel assembly and brake drum(s) removal/installation procedures: a. Discuss these findings with your instructor. b. If instructed by your instructor, carry out the inspection procedure. c. Record the following information: Maximum drum diameter: in/mm Maximum drum out-of-round: in/mm Minimum lining thickness (primary): in/mm Minimum lining thickness (secondary): in/mm d. If fitted with a disc brake system, research the description and operation of the brake system for this vehicle, including the drum brake diagnostic procedure and the wheel assembly and brake drum(s) removal/installation procedures. e. Record the following information: Maximum rotor diameter: in/mm Maximum rotor out-of-round: in/mm Minimum pad thickness (primary): in/mm Minimum pad thickness (secondary): in/mm f. Are these measurements within specifications? g. Refit drum/pad(s) and wheel assembly in accordance with manufacturer s specifications. h. Ensure that the wheel lug nuts are torqued to manufacturer s specification and tightening sequence. i. Wheel lug nut torque: ft/lbs (N/m) j. Actual torque: ft/lbs (N/m) Brakes Inspection Air Brakes Part 2 5

6 9. Discuss the finding(s) with the instructor. Performance Rating 2007 NATEF Reference Number: 7-1D9 7-1D Supervisor/instructor signature Date Brakes Inspection Air Brakes Part 2 6