Standard procedures, inspections, and adjustments
Before working on the pump, clean all dirt and grime from the outside of the pump and surrounding
area.
C
Caution
Contamination can damage internal components and void the manufacturer’s warranty. Take
precautions to ensure system cleanliness when removing and reinstalling system lines.
1. If removing the pump, tag each hydraulic line. If you disconnect hydraulic lines, plug each open port
to ensure that dirt and contamination do not get into the pump.
2. Inpect the hydraulic fluid for signs of system contamination, oil discoloration, foam in the oil, sludge,
or small metal particles.
3. If there are signs of contamination in the hydraulic fluid, replace all filters and drain and clean the
hydraulic system. Fill with the correct hydraulic fluid.
4. Flush the lines before replacing the hydraulic fluid.
5. Before re-installing the pump, test for leaks.
Warranty
Performing installation, maintenance, and minor repairs according to the procedures in this manual will
not affect your warranty. Major repairs requiring the removal of a unit’s front flange voids the warranty
unless done by a Danfoss Global Service Partner.
Pump adjustment
This section offers instruction on adjustment of pump components. Read through the entire topic before
beginning a service activity. Refer to
Port locations and gauge installation
on page 12, for location of
gauge ports and suggested gauge size.
Charge pressure relief valve
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 in one of the case pressure ports L1 or L2. Operate the system with the pump in neutral (zero
displacement) when measuring charge pressure.
2. To adjust charge pressure, shut down system.
3. Using a 1 inch hex wrench, remove charge pressure relief plug (102). Add or remove shims (101) in
relief valve. Adding shims increases charge pressure, while removing shims decreases charge
pressure.
4. Lubricate and install new O-ring (103).
5. Using a 1 inch hex wrench, reinstall plug. Torque to 108 N•m [80 lbf•ft].
6. Operate pump in neutral to verify proper charge setting. Charge pressure is referenced to case
pressure. Subtract case pressure (L1/L2) from charge pressure (M3) to compute actual setting. Repeat
steps 1-5 if necessary.
Service Manual
Series 40 M46 Variable Pumps
Adjustments
18 |
©
Danfoss | September 2017
11026743 | AX00000027en-US0202