Table 4-2. UNIT MAINTENANCE TROUBLESHOOTING-Continued.
TEST OR INSPECTION
Step 2-Check vehicle hydraulic system for proper oil level. Bring vehicle hydraulic oil to proper oil level.
Step 3-Check applicable vehicle manual and ensure hydraulic oil is of proper grade for hydraulic impact wrench
If grade of oil for vehicle does not meet requirements for hydraulic impact wrench operation, discontinue
hydraulic impact wrench operation with vehicle.
Step 4-Inspect hydraulic impact wrench for damaged, worn, or broken parts (see para. 4-19).
Repair hydraulic impact wrench as required (see para. 4-17).
4. Hydraulic Impact Wrench Breaks Fasteners.
Step 1-Refer to flow output and approximate torque output setting as shown in applicable vehicle manual.
Check impacting setting for fastener being torqued.
Adjust impacting setting as shown in applicable vehicle manual.
Step 2-Refer to applicable vehicle manual and ensure proper amount of oil is being supplied for torque required.
Set vehicle controls for required torque.
5. Hydraulic Impact Wrench Leaks Oil.
Inspect hydraulic impact wrench for worn or damaged parts and seals (see para. 4-19).
Replace worn or damaged parts and seals as required (see para. 4-17).
6. Trigger and/or Needle Roller Will Not Disengage When Trigger Is Released.
Step 1-Check freedom of movement of trigger.
Adjust locknut for free trigger movement.
Step 2-Depress trigger and check for smooth engagement of trigger and needle roller.
If needle roller fails to disengage, check relief adjustment screw for proper setting (see para. 4-16).
Step 3-Inspect needle roller and relief valve for wear, distortion, obstructions, or broken parts.
If unserviceable conditions are found, repair hydraulic impact wrench as required (see para. 4-15 or 4-17).
Section V. UNIT MAINTENANCE PROCEDURES
Cleaning instructions are as follows.