NOTE: Removal of crankcase is not required to disassemble variable displacement pump or hydrostatic transaxle. Crankcase is shown removed in this section only for clarity.

NOTE: Variable Displacement pump can be serviced while installed in front mower. If service is to be performed while the hydrostatic transaxle is installed in the front mower, remove the drain plug from the crankcase and drain oil before begining procedure. Some oil will remain in the hydrostatic transmission after the crankcase has been drained.

1. Remove oil lines (A) and for PA420A/PA540A-AS00 and BS00, remove oil line (B). Oil line (B) has been replaced with an internal oil passage for PA420A/PA540A-AS01 and AS02 engines.

2. Remove cover (A) before removing charge pump housing (B).
3. Remove plate (C).
4. Remove inner (D) and outer (E) rotors.
A—Pump Cover
B—Charge Pump Housing
C—Pump Plate
D—Inner Rotor
E—Outer Rotor

IMPORTANT: Remove cylinder assembly (B) carefully so pistons do not fall from the cylinder bores.
5. Push cylinder assembly (B) inward to compress spring
(C) and remove circlip (A).
6. Remove spring (C).
7. Remove O-ring (D).
8. For PA420A/PA540A-AS01 and AS02, remove O-ring (E).
E—O-Ring Assembly Spring

08. June 2021 by samuel07042012
Categories: F510-F525 | Leave a comment

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