Hydraulic Equipment

General Hydraulic Service Notes

Caution

Make sure hydraulic oil temperature has cooled before servicing hydraulic equipment.

Be sure pressure has been relieved from the hydraulic system before servicing hydraulic equipment.

•Plug open hydraulic connections to prevent contamination.

•Wipe oil from components so it will not be mistaken for an oil leak.

•Do not damage plating on cylinder rods.

•Remove/replace cylinders with rods fully retracted.

•Bleed air after installing hydraulic cylinders. Refer to “Bleeding Air After Cylinder Installation” on page283.

•Pressurize the hydraulic system by fully extending each cylinder and tighten the oil filter port plugs after hydraulic component installation to prevent pump cavitation. Check for leaks after pressurization.

•When installing components, clean joint surfaces. Wind sealing tape securely, leaving a space of a thread or two from the tip of the screw. The tape should overlap itself approximately 1/2 inch (12 mm).

Hydraulic Hoses/Piping

•Use care to not twist hoses; use two wrenches during removal/installation to prevent twisting.

•Use the hose marking as a guide to prevent twisting.

•Support hoses having to bend along two different planes, to prevent twisting.

•Be sure hoses do not contact each other after tightening.

•Except when using seal tape, tighten hoses to specified torque, loosen, and then re-tighten to specified torque.

•When installing piping, tighten nuts 1/4 to 1/2 turn after reaching a sharp torque rise point.

•Use elbows on hoses as required to avoid sharp bends, especially hoses at minimum bending radius.

•Use adapters to make the hoses as straight as possible.

•To prevent twisting, hose bends should all be in the same direction to prevent twisting.

•Hose length varies slightly at bends when pressurized; allow for this by not fastening hoses at bends.

•Hose lengths should be slightly longer than necessary. Hoses need ample slack to compensate for elongation/retraction of +2% to -4% when pressurized.

Seals

•Clean O-ring grooves; remove burrs, dirt/dust.

•Do not twist O-rings; correct twists with fingers if necessary.

•Take care not to damage seals during installation.

•Apply grease to the tip of oil seals to prevent wear.

•Floating seals:

•Wipe oil from O-ring and housing after detaching floating seals.

•Before installation, apply gear oil to matching face of the housing.

•Turn seals 2/3 revolutions after installation to improve seating.