Hydraulic Power Unit - Hoses and Fittings - Maintenance

Applies to machines built from: 
October, 1995

Lathe - Hydraulic Power Unit - Hose and Fitting - Maintenance

This procedures tells you how to examine hoses and fittings on a hydraulic power unit (HPU) for damage. The illustrations show the hydraulic hoses for the chuck. The instructions are the same for the other hydraulic hoses.

Push POWER OFF. Before you do maintenance on the HPU, wait until no pressure [1] is in the HPU.
Replace the hose if it has cracks, bumps, wear, or a leak. Look for leaks at the HPU and at the chuck.

At the leak, tighten the female fitting [3] nut with your hand. Do not tighten the fittings too much or you will make cracks in the internal flare [4]. Hold the male fitting [2] with a wrench while you turn the female fitting [3] clockwise 1/8 of a turn with another wrench.

Test for leaks:
Push POWER ON.
Operate the hydraulic function many times to see if the leakage continues. For example, open and close the chucks many times.
If the leakage continues, push POWER OFF to release the pressure [1] from the HPU.
Disconnect the hose. If the internal flare has a crack [4], replace the hose.

Replace the hose:

Connect the new hose at each end. Use your hand to tighten the female fitting [3]. Hold the male fitting [2] with a wrench while you turn the female fitting [3] clockwise 1/8 of a turn with another wrench. Test for leaks again. Use cable ties to move the hoses away from all edges.

Be aware: Many service and repair procedures should be done only by authorized personnel. The service technicians at your Haas Factory Outlet (HFO) have the training, experience, and are certified to do these tasks safely and correctly. You should not do machine repair or service procedures unless you are qualified and knowledgeable about the processes.

Danger: Some service procedures can be dangerous or life-threatening. DO NOT attempt a procedure that you do not completely understand. Contact your Haas Factory Outlet (HFO) and schedule a service technician visit if you have any doubts about doing a procedure.

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