Yamaha F50D Servise Manual page 319

Disassembling the gear pump
9 Make sure that the PTT ram is fully
extended when removing the gear
pump, otherwise fluid can spurt out
from the unit due to internal pressure.
9
When disassembling the gear pump
with the cylinder installed, do not push
the PTT ram down, otherwise fluid can
spurt out.
9
Do not use a rag when assembling the
PTT unit because dust and particles on
the PTT unit components can lead to
poor performance.
9 Do not reuse the O-rings, always replace
them with new ones.
1. Remove the manual valve 1 and gear
pump assembly 2.
2
1
2. Remove the relief valve bracket 3,
down-relief valve 4, and up-relief valve
5 (L transom). NOTICE: Do not remove
the screw 6 and nut 7 (L transom).
Gear pump (disassembling)
å
6
3
7
4
∫
3
4
å L transom
∫ X transom
TIP:
When removing the valve lock screw 8,
make sure to note the number of times it is
turned out from its set position (X transom).
3. Remove the gear pump bracket 9,
down-shuttle piston 0, and up-shuttle
piston q.
9
0
4. Remove the gear pump cover a, down-
main valve w, and up-main valve e.
Then remove the up-relief valve r (X
transom).
5. Remove the drive gear b and driven
gear c.
0
5
1
8
2
3
4
5
6
7
q
8
9
10
A
9-40