Manual displacement control (MDC)
Removal
1. Thoroughly clean external surfaces prior to removal of control.
2. Using a 5 mm internal hex wrench, remove the six control mounting screws (M90). Remove the
control (M1) (with orifice check valve (T40) and spring (T30)) and control gasket (M11) from the
housing. Discard the gasket.
If necessary, remove the control handle (M70) by removing the locking nut (M72) and washer (M71).
C
Caution
Protect exposed surfaces and cavities from damage and foreign material.
Reassembly
1. Install a new gasket (M11). Inspect control to assure that the control orifice check valve and spring are
in their proper position in the control.
2. Install the control. Engage the pin on the control linkage into the mating hole in the link attached to
the swashplate.
3. With the control in position, move control lever both directions to check proper engagement of
control linkage pin. If properly assembled, lever will return to center. If lever does not return to center,
remove the control and repeat the above procedure.
If removed, install the control handle (M70) and locking nut (M72) with washer (M71). Hold the
position of the handle and torque the locking nut to 13.5 N•m [10 lbf•ft] using an 8mm hex wrench.
4. Align the control gasket and install the screws. Torque the screws to 16 N•m [12 lbf•ft].
W
Warning
The neutral start switch neutral must be readjusted after reassembling the MDC module.
Install a sealing washer under the head of mounting screws that are installed into through holes in
the housing.
5. If the control is equipped with a neutral start switch, refer to MDC Neutral start switch adjustment
instructions.
Service Manual
Series 90 Pumps
Minor repair
520L0818 • Rev 0101 • August 2015
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