System Operating Hot
Item
Descriptin
Action
Check fluid level in reservoir.
Insufficient volume of hydraulic fluid
will not meet cooling demands of
system.
Fill reservoir to proper level. Verify
proper size of reservoir.
Inspect heat exchanger. Check air
flow and input air temperature for
the heat exchanger.
Insufficient air flow, high input air
temperature, or undersized heat
exchanges will not meet cooling
demands of the system.
Clean, repair, or replace heat
exchanger as required. Verify proper
size of heat exchanger.
Check external system relief valve
setting.
Fluid passing through relief valve
adds heat to system.
Adjust external system relief valve
setting following manufacturer’s
recommendations. External relief
valve setting must be above PC
setting for proper operation.
Check pump inlet pressure / vacuum. High inlet vacuum adds heat to
system.
Correct inlet pressure / vacuum
conditions.
High Inlet Vacuum
Item
Description
Action
Check fluid temperature.
Low temperature increases viscosity.
High fluid viscosity causes high inlet
vacuum.
Allow system to warm up before
operating.
Inspect inlet screen.
Blocked or restricted inlet screen
causes high inlet vacuum.
Clean screen / remove blockage.
Check inlet piping.
Too many fittings, bends, or long
piping causes high inlet vacuum.
Eliminate fittings to make path more
direct.
Hydraulic fluid viscosity above
acceptable limits.
High fluid viscosity causes high inlet
vacuum.
Select fluid with appropriate viscosity
for expected operating temperature.
C
Caution
High inlet vacuum causes cavitation which can damage internal pump components.
Service Manual
D1 High Power Open Circuit Pumps Size 65/130/145/193/260
Troubleshooting
34 |
©
Danfoss | July 2019
L1527453 | AX00000292en-CN0201