Damcos LPU: Troubleshooting Guide LPU Service Manual
February 2017 SM 8000-100-01 Ed 04
51
Pump rendering too low (or no) pressure in one or both
directions
Action: • Check that solenoid valve is clicking at connection. If not see “Solenoid valve not working” on
page 52.
• If pump does not render any pressure at all check oil level.
Mount a plug giving a possibility of connecting compressed air instead of breather valve and
pressurize tank with maximum 2.5 bar, while the pump is running. If air pressure in tank does not
solve the problem, or if the pump renders pressure (but too low), hand pump with pressure
gauge is mounted and actuator is fully opened by hand pump.
LPU-D
If no opening pressure check that by-pass for tank filling (in front of LPU) is closed.
LPU-Power
Check that power supply is connected to terminal “open” and that terminal “close” is not connected.
If pressure remains constantly low
At too low pressure in one direction (LPU-S) or both directions (LPU-D) the safety valve is adjusted
according to instruction (see “Pump pressure adjustment for LPU” on page 85). If higher pressure
cannot be obtained, there is a possible leakage in the solenoid valve, or at DPCV-slide (LPU-D), or at
clearance between pump stator and rotor.
De-airing the flow reducing valve may be necessary, see “Pump not rendering sufficient oil at low
pressure (“valve running too slowly”)” on page 61.
If pressure drops quickly
Leakage in bypass valve (actuator), shuttle or emergency valve (LPU-S) or release valve. Check o-rings
on valves and if necessary replace release valve (see “Replace release valve in LPU” on page 99) or
shuttle valve.
To Next Page
Loading...
