Service Manual and
Axial Piston Pumps Series 20
Repair Instructions
L1003506
• Rev BA • Jun 2014
14
Checking the charge pressure
Checking the charge pump
Checking the charge check valves
1. Remove charge pump to examine check
valves (see
page 21
).
1. Inspect if contamination is holding the valve
open and for galling or wear on valve cone
and seat and inspect for broken spring.
2. The shaft and gear teeth must work freely.
3. Further disassembly of the charge pump is not
permitted.
2. Check the spring pressure and for correct
operations. Check if conta mination may be
prohibiting free movement of the ball.
Inspection Instructions
F000 077
F000 078
F000 079
F000 080
Hex-plug, Spring
3
Shims Valve cone
5+6 10
5+6
Troubleshooting
1. Clean the charge pressure gauge connection
on the pump.
2. Pressure gauge (see recommended measuring
instruments) to be connected.
3. Set operating speed at 1500 min
-1
4. Charge pressure with the pump in neutral ca.
15 - 18 bar [218 - 261 psi]. When the pump in
forward or reverse the charge pressure should
be at a two bar lower level (purge relief valve,
motor).
