CHARGE PRESSURE
RELIEF VALVE REMOVAL
1. Clean pump externally with clean solvent to
remove debris.
2. Using a 27 mm wrench, remove the charge
pressure relief valve. (V10)
1. Lubricate the external O-rings using petroleum
jelly.
2. Install the new charge pressure relief valve.
Using a 27 mm socket, torque to 47-57 N•m
[35-42 lbf•ft]
CHARGE PRESSURE
RELIEF VALVE
INSTALLATION
CHARGE PRESSURE
RELIEF VALVE
ADJUSTMENT
1. Install a 50 bar [1000 psi] pressure gage in charge pressure gauge port M3 (next to the adjust-
ment screw). Install a 10 bar [100 psi] gauge at one of the case drain pressure ports L1, L2,
L3, or L4. Operate the system with the pump in neutral (zero displacement) when measuring
charge pressure.
2. The table shows the acceptable pump charge pressure range for some nominal charge relief
valve settings (refer to the model code located on the serial number plate). These pressures
assume 1800 pump rpm and a reservoir temperature of 50°C (120°F), and are referenced to
case pressure.
3. Adjust valve. Clockwise rotation of the adjusting screw increases the setting, and counter-
clockwise rotation decreases the setting.
4. Torque locknut to 17.5 N•m [12.9 lbf•ft] using a 19 mm socket.
5. When desired charge pressure is achieved, rem
ove the gauges and plug the ports.
Charge pressure ranges
Model code Measured charge pressure*
20 bar [290 psi] ± 1.5 bar [21.8 psi]
24 bar [348 psi] ± 1.5 bar [21.8 psi]
26 bar [377 psi] ± 1.5 bar [21.8 psi]
30 bar [345 psi] ± 1.5 bar [21.8 psi]
* This is the actual charge pressure port
gauge reading minus the case pressure
port gauge reading. Factory set at 1800
min
-1
(rpm) with a reservoir temperature
of 50° C (120° F)
Listed pressures assume a
pump speed of 1800 rpm. At
higher pump speeds (with
higher charge flows) the
charge pressure will rise over
the rated settings.
V10
60 N•m [45 lbf•ft]
27 mm
Adjusting screw
5 mm
Locknut
19 mm
Case drain port L2
17.5 N•m
[12.9 lbf•ft]
0 - 10 bar [0 - 100 psi]
95-136 N•m [70-100 lbf•ft]
Charge pressure gauge port M3
0 - 50 bar [0 - 1000 psi]
20-27 N•m [15-20 lbf•ft]
1/4 inch
9/16 inch
© Danfoss, 2013 BLN-10282 • Rev AA • September 2013 1
Service Kit Instructions
H1 pump
Charge pressure relief valve replacement procedure
