Yamaha 55DEHD - Gear Pump; Disassembling the Gear Pump, down Relief Valve and Main Valve

6885J11
7-48
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Gear pump
Disassembling the gear pump, down
relief valve and main valve
1. Drain the PTT fluid.
2. Remove the spring 1 and filter 2.
3. Remove the bolts 3, and then remove
the gear pump assembly 4.
4. Remove the O-rings 5, down-relief
spring 6, valve support pin 7 and main
valve seal 8.
5. Remove the main valves 9 and shuttle
piston 0.
6. Hold the gear pump assembly 4 in a vice
using aluminum plates a on both sides,
and then remove the pins q.
NOTE:
Use a 4 mm pin punch w to remove the pins
q.
7. Separate the gear housing 2 e as
shown, then remove the balls r, drive t
and driven gear y.
NOTE:
Turn the gear pump assembly upside down,
and then separate the gear housing 2 e.
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