Medium Heavy Vehicle Air Brakes 7 1

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1 Medium Heavy Vehicle Air Brakes 7 Student/intern information: Name Class Vehicle used for this activity: Year Make Model Odometer VIN Learning Objective / Task Parking Brake Inspect and test parking (spring) brake chamber diaphragm and seals; replace parking (spring) brake chamber; dispose of removed chambers in accordance with local regulations. Inspect and test parking (spring) brake check valves, lines, hoses, and fittings; replace as needed. Inspect and test parking (spring) brake application and release valve; replace as needed. Manually release (cage) and reset (uncage) parking (spring) brakes in accordance with manufacturers recommendations NATEF Reference Number 2007 NATEF Priority Level 3A3-1 P-1 3A3-2 P-1 3A3-3 P-1 3A3-4 P-1 Recommended Resource Materials CDX Automotive program CDX etextbook 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 with possible engine concern Vehicle manufacturer s workshop manual Manufacturer-specific tools depending on the concern Vehicle lifting equipment if applicable For every task in Brakes, the following safety task must be strictly enforced: Comply with personal and environmental safety practices associated with clothing; eye protection; hand protection; proper lifting practices; hand tools; power equipment; proper ventilation; and the handling, storage, and disposal of fuels/chemicals/materials in accordance with federal, state, and local regulations. 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), ensure you 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. Medium Heavy Vehicle Air Brakes 7 1

2 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. 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 Inspect and test parking (spring) brake chamber diaphragm and seals; replace parking (spring) brake chamber; dispose of removed chambers in accordance with local regulations. 3A Inspect and test parking brake chamber(s) diaphragm, and seals. a. Reference manufacturer s workshop for the correct procedure for checking the parking brake chamber(s), diaphragm and seals: Inspect and test parking brake operation: i. Ensure the air pressure has been completely built up; apply parking brake: Operational: Require servicing: If require servicing, list the problems lights and your recommendation(s): ii. Check to ensure all park brake chamber have applied: Yes: No: If no, list the problem light and cover and your recommendation(s): 2. Replace parking (spring) brake chamber. a. Reference manufacturer s workshop manual for the correct procedure for replacing the parking brake chamber(s), including all safety precautions: i. List the procedure and all safety requirements when replacing a parking (spring) brake chamber assembly: ii. Discuss the procedure with instructor. Medium Heavy Vehicle Air Brakes 7 2

3 iii. If directed by your instructor, replace the parking brake chamber in accordance with the manufacturer s procedure and safety requirements. b. Replace parking (spring) brake chamber in accordance with the manufacturer s workshop manual. Removal: i. As outline in the workshop manual, fit manual cage retaining bolt ii. Disconnect the air line hoses and seal hoses from the environment. iii. Remove clevis pin. iv. Remove mounting bolts and remove parking (spring) brake chamber. Replacement: v. Install new parking (spring) brake chamber and fit and torque mounting bolts. vi. Adjust push rod to align with clevis pin and refit clevis pin and cotter pin. vii. Remove protective covers from brake hoses and reconnect in the correct manner as outlined in the workshop manual. 3. Referencing local, and where necessary, state/federal legislation/regulations workshop for the correct procedure for disposing of a used parking (spring) brake chamber(s): a. Discuss the finding with instructor. b. If directed by your instructor, carry out this procedure NATEF Reference Number: 3A3-1 Task Inspect and test parking (spring) brake check valves, lines, hoses, and fittings; replace as needed. 3A Inspect and test parking (spring) brake check valves; replace as needed. 2. Inspect and test lines, hoses, and fittings; replace as needed NATEF Reference Number: 3A3-2 Medium Heavy Vehicle Air Brakes 7 3

4 Task Inspect and test parking (spring) brake application and release valve; replace as needed. 3A Inspect and test parking (spring) brake application and release valve: a. Check air system for air leaks (brakes released): Following the procedure from workshop manual; check the air brake system components for air leaks: No Leaks: Leaks: If leaks are detected, list the areas and your recommendation(s): b. Check air system for air leaks (brakes applied): Following the procedure from workshop manual, recheck the air brake system components for air leaks: No Leaks: Leaks: If leaks are detected, list the areas and your recommendation(s): c. Check the serviceability of parking (spring) brake actuating valve: Are these components within specifications? Yes: No: If no, list the problem and your recommendation(s): 2007 NATEF Reference Number: 3A3-3 Medium Heavy Vehicle Air Brakes 7 4

5 Task Manually release (cage) and reset (uncage) parking (spring) brakes in accordance with manufacturers recommendations. 3A If directed by your instructor, carry out this procedure. 2. Discuss the finding with instructor NATEF Reference Number: 3A3-4 Medium Heavy Vehicle Air Brakes 7 5