Adjustments; Standard Procedures, Inspections, And Adjustments; Charge Pressure Relief Valve Adjustment - Danfoss T90 Series Service Manual

Service Manual
Series T90 Axial Piston Pumps

Adjustments

Standard procedures, inspections, and adjustments

Adjustments

Charge pressure relief valve adjustment

© Danfoss | March 2020
Before working on the pump, clean the outside of the pump.
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 connected to the pump. If hydraulic lines are
disconnected, plug each open port with a clean plug, to ensure that dirt and contamination do not
get into the pump.
3. Ensure the surrounding areas are clean and free of contaminants.
4. Inspect the system for contamination.
5. Visually inspect the hydraulic fluid for signs of system contamination, fluid discoloration, foam in the
fluid, sludge, or small metal particles.
6. If there are signs of contamination in the hydraulic fluid, replace all filters, drain and flush the
hydraulic system, and fill with the correct filtered hydraulic fluid.
7. Flush the lines before replacing the hydraulic fluid.
This section offers instruction on inspection and adjustment of pump components. Read through the
entire related section before beginning a service activity. Refer to
gauge ports and suggested gauge sizes.
The following procedure explains how to check and adjust the charge pressure relief valve.
W
Warning
The following procedure may require the vehicle/machine to be disabled (wheels raised off the ground,
work function disconnected, etc.) in order to prevent injury to the technician and bystanders. Take
necessary safety precautions before moving the vehicle/machine.
1. Install a 50 bar [1000 psi] pressure gauge in the pump charge pressure gauge port (M3). Install a 10
bar [100 psi] gauge to measure case pressure (tee into L1 or L2 or use servo gauge port M4 or M5).
Operate the system with the pump in neutral (zero displacement) when measuring pump charge
pressure.
Pressure measurement for location of
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