Malfunction
Probable Cause
Hot to Determine
Corrective Action
Page
Steps
3. Excessive noise, cavit- Oil
Check oil for excessive viscosity
Replace as necessary
ation and internal damage
Continued
Check for water in oil
Replace as necessary - check heat
exchanger for possible leaks
Check case drain line for steel
Unit probably beyond field repair.
or brass particles
Remove and overhaul
Air in oil
Check inlet line for leaks
Tighten fittings or replace as
necessary
Check oil level in reservoir
Add oil as necessary
Maintain oil level above level of
return line
4. Overheating
Excessive internal wear
Check case drain. Volume should
Unit probably beyond field repair.
not exceed GPM per 1000 psi
Remove and overhaul.
working pressure per unit
Relief valves
Check relief valve setting
Set relief valves a minimum of 500 129
C4
psi above normal operating pressure or
500 psi above override control setting,
whichever is highest
5. Loss of Pressure
Relief valve malfunction
Check pressure with motor stalled
Adjust relief valve or replace as
at points indicated below. Pres-
necessary
sure should be within 100 psi of
value on name plate
Figure 103.
Remove high pressure relief valve
Replace or adjust as necessary
C-2
assembly and check for cut O-Rings
Check small hole in high pressure
If plugged, clean or replace as
C-2
relief valve for burrs or contamination
necessary
87
