This section offers instruction on inspection and adjustment of pump components. Read through the
entire topic before beginning a service activity.
Refer to
Pressure Measurements
for location of gauge ports and suggested gauge size.
Standard Procedures
C
Caution
Contamination can damage internal components and void your warranty. Take precautions to ensure
system cleanliness when removing and reinstalling system lines
1. With the prime mover off, thoroughly clean the outside of the pump.
2. If removing the pump, tag each hydraulic line. When you disconnect hydraulic lines, cap them and
plug each open port to prevent contamination.
3. Ensure the surrounding area is clean and free of contaminants like dirt and grime.
4. Inspect the system for contamination.
5. Check the hydraulic fluid for signs of contamination: oil discoloration, foam in the oil, sludge, or metal
particles.
6. If there are signs of contamination in the hydraulic fluid, replace all filters and drain the hydraulic
system. Flush the lines and refill the reservoir with the correct filtered hydraulic fluid.
7. Before re-installing the pump, test for leaks.
Charge Pressure Relief Valve Adjustments
This procedure explains how to check and adjust the charge pressure relief valve.
1. Install a 50 bar [1000 psi] pressure gauge in charge pressure gauge port M3. Install a 10 bar [100 psi]
gauge at case drain port 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 model code located on serial number plate). These pressures assume 1800 min-1
(rpm) pump speed and a reservoir temperature of 50°C [120°F], and are referenced to case pressure.
Charge Pressure Adjustment
Case drain port L4
Charge pressure gauge port M3
Adjustment
screw
5 mm
Locknut
13 mm
Case drain port L2
P104466
12 N•m
[9 lbf•ft]
Optional construction port M14
0 - 10 bar [0 - 100 psi]
9/16 (069/078) / 5/8 in (147/165/210/250)
70 N•m [52 lbf•ft] (078)
150 N•m [110 lbf•ft] (147/165/210/250)
0 - 10 bar [0 - 100 psi]
3/8 in (069/078) /
9/16 in (089/100/147/165)
5/8 in (210/250)
70 N•m [52 lbf•ft]
0 - 10 bar [0 - 100 psi]
3/16 in
0 - 50 bar [0 - 1000 psi]
1/4 in
12 N•m [9 lbf•ft]
24 N•m [18 lbf•ft]
Listed pressures assume a pump speed of 1800 min¯¹ (rpm). At higher pump speeds (with higher
charge flows) the charge pressure will rise over the rated setting.
Depending on the pressure rating, the charge pressure relief valve may have one or two springs.
Service Manual
H1 Pumps 069/078, 089/100, 115/130, 147/165, 210/250
Adjustments
©
Danfoss | May 2018
520L0848 | AX00000087en-US0308 | 31
