ACTUATOR 2913999 - Caterpillar

Personal injury can result from hydraulic oil pressure and hot oil.Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system.Make sure all of the attachments have been lowered to the ground, and the oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.
To prevent personal injury when checks are made while the machine is in operation, make sure only approved personnel are on the machine. Keep other personnel off the machine and in view of the operator. Make sure checks are done in an open area.
Note: Use the information in the reference to prepare the machine for this test. Also, use the information in the reference to relieve any system pressure that may be present in the hydraulic system.Reference: For the correct procedure in order to relieve any hydraulic oil pressure that may be present in the hydraulic system, refer to Testing and Adjusting, "Machine Preparation for Troubleshooting" for your machine.
Table 1
Required Tools    
Part Number     Description    
9U-7401     Multitach    
9U-5140     Photo Pickup    
1U-6605     Reflective Tape    
Illustration 1 g00594486
(1) Damper. (2) Reflective tape.
Install a 19 mm (.75 inch) piece of reflective tape (2) onto damper (1). Damper (1) is located on the engine, left of the fan.
Connect 9U-5140 Photo Pickup to the 9U-7401 Multitach .
Illustration 2 g00638953
(3) Photo pickup. (4) Magnetic stand.
Attach photo pickup (3) to magnetic stand (4). Place magnetic stand (4) onto the machine. Refer to illustration 2 for the proper placement.Note: Be sure that all cables and diagnostic equipment are clear of all moving parts before starting the engine.
Start the engine.
Warm the hydraulic oil to normal operating temperature. Normal operating temperature is 60° 10°C (140° 18°F).
After the oil has reached normal operating temperature, lower the grapple to the ground.
Stop the engine.
Release all hydraulic system pressure.
Illustration 3 g00638962
(5) Main pressure relief valve. (6) Main control valve (three bank). (7) Locknut. (8) Adjustment screw for the main pressure relief valve. (9) Main control valve (four bank).
Loosen locknut (7) on the main pressure relief valve.
Turn adjustment screw (8) clockwise by one complete turn.Note: Adjusting the main pressure relief valve will allow a greater amount of hydraulic oil flow to the implement cylinders. In order to test the torque limiter, a large amount of oil flow must be produced by the piston pump. The torque limiter will limit the amount of oil flow that can be produced by the pump. The torque limiter is preset according to the torque from the engine output. The torque limiter will restrict the pump output when the torque on the engine is too high.
Tighten locknut (7) on the main pressure relief valve.
Start the engine.
Run the engine at high idle. High idle speed for this machine