Hydraulic System 147
4. Make sure that all hoses are tight and not leaking.
5. Connect a pressure gauge (0–4000 psi) to the quick-connect coupler on the proportional valve
(see Figure 5-25).
Figure 5-25
Installing the pressure gauge
6. Put the transmission in Neutral, start the engine and engage the hydraulic pump.
7. Adjust gripper pressure:
7 a. Close the gripper using the corresponding lever on the valve.
7 b. While maintaining the lever in place, adjust the relief valve of the “gripper close” side of the
valve section to 1200 psi
1
(screw or unscrew depending on the gauge readout).
7 c. Open the gripper and maintain the lever in place.
7 d. Adjust the pressure of the “gripper open” load/sense relief valve to 1200 psi.
Figure 5-26
Gripper load/sense relief
Adjusting High Pressure on 300-Gallon Grippers
To adjust high pressure on 300-gallon gripper built-in relief valves:
1. Lock out and tag out the vehicle (see Locking Out and Tagging Out the Vehicle on page 12).
2. Secure the area around the path of the arm with barrier tape or barricades.
1. Reference value varies according to use. This pressure can be adjusted according to customer’s needs.
Here