3. Unthread both servo cylinders 2-3 turns using servo can tool (Tool ID DLD-6247). This step ensures
the servo cylinders have no contact with the servo piston.
4. Stroke the pump by turning the adjusting screw (or supplying current to solenoid C1) until the servo
pressure at port M4 is 1 to 2 bar [14– 29 psi] greater than at port M5 and the system pressure gauges
indicate displacement. Pressure should be greater at port MA for clockwise rotation, or MB for
counter clockwise rotation. This also indicates the servo piston is in contact with the servo cylinder on
side M5.
A small pressure differential of 1.5 bar [22 psi] or less is acceptable. Achieving zero differential is
usually not possible.
5. Slowly thread the servo cylinder on the M5 side in until the system pressure differential starts to
decrease. Maintain servo pressure differential between 1-2 bar [14-29 psi] during this step. Continue
turning the servo cylinder in until the system pressure differential (between ports MA/MB) is less than
1.5 bar [22 psi]. This procedure sets the servo and swashplate to mechanical neutral on the M5 side.
6. To complete setting neutral, repeat steps 1-5 but stroke the pump in the opposite direction by
turning the adjusting screw in the opposite direction, or by supplying current/hydraulic pressure to
solenoid C2. Reverse gauge locations (M4 for M5, MB for MA) from those stated above since the
pump is now stroking the other direction.
7. Remove all gauges and replace gauge port plugs.
Servo adjustment
P108967
Servo cylinder
locking bolt
Servo cylinder
locking plate
Verify neutral setting
1. If using a PWM signal to set mechanical neutral, check that servo pressure differential is less than 1.5
bar [22 psi]. Refer to TS-422 or Control neutral adjustment.
2. To verify mechanical neutral, provide current to solenoid C1, or turn neutral adjusting screw, until the
servo pressure differential is 3 bar [43 psi]. The system pressure differential must be below 1.5 bar [22
psi]. Repeat test on solenoid C2 side.
3. The current required to set the servo pressure differential to 3 bar [43 psi] should be the same for
each solenoid. Refer to TS-422.
4. If using neutral adjusting screw to set mechanical neutral, reset control neutral.
Servo Adjustment Side M4
1. Run prime mover at 1800 rpm.
2. If using a PWM signal to set mechanical neutral, start with the electronic control testing tool off (no
current/hydraulic pressure to either solenoid). Check to be sure the servo pressure differential is less
Service Manual
MP1
Adjustments
50 |
©
Danfoss | April 2019
AX00000244en-000201