Hydraulic System 151
Figure 5-30
Pressure adjustment values
Pressurizing the Tank System
NOTE: For chassis-mounted tanks only. No pressurization is needed for behind-the-cab mounted
tanks; gravity is enough to cause the oil to flow.
Cavitation inside the pump generates excessive wear and noise.
To prevent cavitation, air pressure inside the hydraulic tank must be set between 3 and 3.5 psi. A
gauge and a pressure regulator are installed to adjust air pressure inside the tank. This gauge is located
inside the frame rail on the curbside of the chassis; it can be accessed only when the body is raised.
To adjust the pressure, turn the knob until the pressure reaches 3 to 3.5 psi. The hydraulic tank is also
equipped with a 5-psi relief valve and a pressurized screw-on filler cap.
Danger!
Install body safety prop before performing any work under the body.
Adjust to
1800 psi
Adjust to
1200 psi
Adjust to
1200 psi
Arm horizontal movement
Arm vertical movement
Gripper
Crusher panel