Medium Heavy Vehicle Hydraulics Student/intern information: Name Class Vehicle used for this activity: Year Make Model Odometer VIN Learning Objective / Task (Actuators) 2007 NATEF Reference Number 2007 NATEF Priority Level Identify actuator type (single/double acting, F1-1 P-1 multi-stage/telescopic, and motors). Identify the cause of seal failure; determine F1-2 P-2 needed repairs. Identify the cause of incorrect actuator movement F1-3 P-2 and leakage (internal and external); deter- mine needed repairs. Inspect actuator mounting, frame components, F1-4 P-2 and hardware for looseness, cracks, and damage; determine needed action. Remove, repair, and/or replace actuators in F1-5 P-2 accordance with manufacturers recommended procedures. Inspect actuators for dents, cracks, damage, and F1-6 P-2 leakage; determine needed action. Purge and/or bleed system in accordance with manufacturers recommended procedures. F1-7 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 hydraulic concern Vehicle manufacturer s workshop manual Manufacturer-specific tools depending on the concern Vehicle lifting equipment if applicable For every task in Hydraulics, 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. In addition, comply with manufacturers and industry accepted safety practices associated with equipment lock out/tag out; pressure line release; implement/support (blocked or resting on ground); and articulated cylinder devices/machinery safety locks. Medium Heavy Vehicle Hydraulics 1
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 OSHAapproved 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. 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 Identify actuator type (single/double acting, multi-stage/telescopic, and motors). F1-1 1. Reference the manufacturer s workshop manual and/or component manufacturer s manuals and identify the actuator type (single/double acting, multi-stage/telescopic, and motors). 2. Carry out a visual inspection of your vehicle while referencing the manuals. a. List the components fitted to your vehicle and their locations: 2007 NATEF Reference Number: F1-1 Medium Heavy Vehicle Hydraulics 2
Task Identify the cause of seal failure; determine needed repairs. F1-2 1. Reference the manufacturer s workshop manual and/or component manufacturer s manuals and identify the cause of seal failure. a. List all possible causes: b. Other alternative causes: 2. From the list above, determine what actions should be taken to rectify these causes: a. Other alternative causes: 3. Carry out a visual inspection of the hydraulic components fitted to your vehicle while referencing the manuals. 2007 NATEF Reference Number: F1-2 Medium Heavy Vehicle Hydraulics 3
Task Identify the cause of incorrect actuator movement and leakage (internal and external); determine needed repairs. F1-3 1. Reference the manufacturer s workshop manual and/or component manufacturer s manuals and identify the cause of incorrect actuator movement and leakage (internal and external). a. List all possible causes: b. Other alternative causes: 2. From the list above, determine what actions should be taken to rectify these causes: a. Other alternative causes: 3. Carry out a visual inspection of these hydraulic components fitted to your vehicle while referencing the manuals. 2007 NATEF Reference Number: F1-3 Medium Heavy Vehicle Hydraulics 4
Task Inspect actuator mounting, frame components, and hardware for looseness, cracks, and damage; determine needed action. F1-4 1. Carry out a through visual inspection of all actuator mounting, frame components, and hardware for looseness, cracks, and damage. 2007 NATEF Reference Number: F1-4 Task Remove, repair, and/or replace actuators in accordance with manufacturers recommended procedures. F1-5 1. Identify the recommended procedure for removing and installing the pump; prime and/or bleed the system. 2. Reference the manufacturer s workshop manual for the correct procedure for removing, repairing, and/or replacing the actuators. a. List the procedure and all safety requirements for removing, repairing, and/or replacing the actuators: 3. Following the procedures outlined above, and taking into account all safety precautions, remove, repair, and/or replace the actuators. a. While using a collection container adequate for the amount of oil to be drained, drain the power steering fluid. b. Collect an oil sample in a clean, sterile container to be sent for analysis. c. Remove the inlet and outlet hoses, collecting any fluid coming from the removed hoses. Medium Heavy Vehicle Hydraulics 5
d. Remove the hydraulic actuator and place on the work bench. 2007 NATEF Reference Number: F1-5 Task Inspect actuators for dents, cracks, damage, and leakage; determine needed action. F1-6 1. Inspect the actuator and determine the most appropriate course of action: repair or replace. 2. With the actuator removed, inspect for dents, cracks, damage, and evidence of leakage. 3. If directed by your instructor to replace the actuator: a. Select a replacement hydraulic actuator and compare it with the removed original. b. Inspect the inlets and outlets to ensure that there is no evidence of restrictions. 4. Discuss the findings with your instructor. 2007 NATEF Reference Number: F1-6 Task Purge and/or bleed system in accordance with manufacturers recommended procedures. F1-7 1. Following the procedures outlined in the component and/or manufacturer s manual, and taking into account all safety precautions, replace the hydraulic actuator. a. Change over the hose connection components if necessary. b. Prime the replacement actuator and then plug the pump outlets. Medium Heavy Vehicle Hydraulics 6
c. Refit the new hydraulic actuator to the vehicle and tension all mounting bolts to the correct torque. i. Manufacturer s recommended torque: ii. Actual torque: d. Remove the plugs and refit the hoses. e. Refill the hydraulic fluid reservoir with the correct fluid and quantity. i. Correct type of fluid (name): ii. Recommended fluid quantity: iii. Actual amount of fluid added: f. If applicable, purge and/or bleed the hydraulic actuator fluid system to remove air, as outlined in the manufacturer s workshop manual. g. Start and run the engine. Operate the hydraulic system and check for any leaks and security of the pump mounting. h. Rectify any leaks. i. Check and adjust the hydraulic fluid levels. 2. Discuss the findings with your instructor. 2007 NATEF Reference Number: F1-7 Medium Heavy Vehicle Hydraulics 7