Troubleshooting


PROBLEM
Variations in flow











Improper flow rate








Fluid is overheating

PROBABLE CAUSE
A) Valve compensator spool binding


B) Insufficient pressure differential across the orifice

C) Fluid viscosity too high or too low (needle valve and pressure compensated valves)


A) Needle valve adjustment incorrect

B) Additional line restriction



C) Restrictions in valve passages or orifice area.
A) Excess flow over relief valve




B) System pressure too high

C) Contamination

POSSIBLE REMEDY
A) Disassemble and clean, flush system.  Check for burrs on spool and body.

B) Increase system pressure.  Decrease system load.

C) Warm oil to normal operating temperature.  Change fluid to recommended SSU.  Change valve to temperature pressure compensated valve.
A) Readjust needle valve.


B) Check for collapsed or kinked lines.  Check for proper tube fitting and hose size.

C) Disassemble and clean; flush system.
A) Adjust pump GPM (variable volume pump).  Reduce pump RPM's.  Change to small GPM pump.

B) Lower system pressure.

C) Drain, clean and flush system.