Yamaha F225F Service Manual page 527

Disassembling the gear pump
housing
1. Remove the manual valve a, and then
remove the gear pump assembly b.
2. Remove the filters c.
c
c
a
3. Remove the valve lock screws d, and
then remove the spring e, valve support
pin f, ball g, spring h, valve pin i,
and valve seal j.
d
h
i
j
A
a
d
A Down-relief valve
B Up-relief valve
TIP:
Before removing the valve lock screws d,
measure and write down the screw depth a
and screw height b.
b
d
e
f
g
B
b
d
4. Remove the bracket k, and then remove
the filter l, spacers m, springs n, valve
pins o, and balls p and q.
k
m
l
n
o
p
5. Remove the gear housing c, and then
remove the springs r, down-main valve
s, and up-main valve t.
6. Remove the drive gear d, driven gear
e, balls u, and pins v.
r
s
e
u
Checking the gear pump
1. Check the drive gear a and driven gear
b. Replace the gear pump assembly if
damaged or worn.
2. Check the up-relief valve c and down-
relief valve d. Clean if there is dirt or
residue.
3. Check the main valves e. Clean if there
is dirt or residue.
PTT gear pump
0
m
n
1
o
p
2
q
3
4
5
c
6
v
r
7
t
d
8
9
10
A
9-48