Norton Abrasives C3126, C3120 B. Relief Valve Pressure Too Low 1. Symptoms, B. Repair as follows

label). On the "inline" style relief valve the return lines, threaded into the back, will have to be removed in order to reach the adjusting screw. The "internal" relief valve is adjusted with a screw driver and the "inline" relief is adjusted with a 1/4" alien key.

B. Relief Valve Pressure Too Low:

1. Symptoms:

•Motor RPM is faster than normal.

•Cylinder will not extend.

•Excessive turbulence in the reservoir.

NOTE: On applications where the cylinder is being replaced or the mechanical mechanism is being modified, make sure the pressure capability of the pump is not being exceeded.

13.Diagnosing and Repairing Hydraulic Pump Relief Valves:

A.Two possible causes for lack of pressure

•The adjusting screw has backed up.

•Foreign matter or "dirt' is trapped between the seat and the ball or cone.

B.Repair as follows:

•Using a gauge tee'd into the pressure line, turn the adjusting screw clockwise a turn or two and watch the gauge; if it goes up, continue to turn the screw until the required setting is reached. If the screw does not remain in the correct position, replace it with one that has a locking patch (In an emergency the screw threads can be deformed slightly with a small prick punch and hammer to hold the setting.)

•If the pressure does not climb when the adjusting screw is tightened; turn the adjusting screw counterclockwise all the way out: energize the pump to 'flush' the dirt past the seat:

CAUTION: use hand or a piece of hose to divert oil into a container. Do not look into the port.)

NOTE: In an emergency, if a pressure gauge is not available, turn the relief valve screw in until the cylinder moves under worst conditions and then tighten 1/2 to 3/4 additional turns.

C. If the above mentioned procedure fails to increase the relief valve setting, check for a worn pump or leaking cylinder

14.Troubleshooting and Repairing Hydraulic Pump Relief Valves A. Load drift failure

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