Servicing; Manifold Removal; Valve Assembly Removal; Soap Injector Assembly Removal - Yamaha PW3028A Service Manual

SERVICING

1. Loosen manifold hex socket head screws. See
figure 13, page 19.
2. Loosen valves caps.
3. Loose unloader valve and remove unloader valve.
See figure 15, page 20.
4. Loosen soap injector assembly (U). See figure 15,
page 20.

MANIFOLD REMOVAL

1. Using an 5 mm hex key, remove the hex socket
head screws from the face of the manifold head.
See figure 13, page 19.
2. Insert flat head screwdrivers on each side between
the crankcase and manifold head. Gently apply
pressure to the head to begin separation.
3. Support the manifold head from the underside and
pull the manifold head away from the crankcase.
CAUTION:
Keep the manifold head properly aligned
with the ceramic plungers when removing to
avoid damage to the plungers. The seal case
may stay in the manifold or on the ceramic
plungers.

VALVE ASSEMBLY REMOVAL

NOTE: Pump requires one stacked valve kit for repair.
Discharge and inlet valve assemblies may
stay together or separate during removal.
Spring retainer may also separate from the
seat during removal.
1. Depending on pump model use a 19 mm or 24
mm wrench to remove valve plugs (A) on top of
manifold. See figure 8, page 18.
2. Use reverse pliers to remove stacked valve
assemblies from valve chamber (C-J).
3. If the discharge valve assembly separates from
the inlet valve assembly, use a reverse pliers to
remove it from the valve chamber.
CAUTION:
Exercise caution as the reverse pliers may
damage the threads in valve chamber or spring
retainer.
4. The spring retainer (F) may separate from the seat
(E). Remove the spring (D) and valve from the valve
chamber (C and I).
5. Separate valve assembly by inserting screwdriver
into spring retainer and press the backside of valve
until seat separates from the spring retainer.
6. Remove o-ring (B and K) from each seat and valve
plug.

SOAP INJECTOR ASSEMBLY REMOVAL

1. Remove soap injector assembly (U). See figure
15, page 20.
2. Remove soap injector kit (V) from soap injector
assembly (U).
3. Remove spring.
4. Remove ball bearing.
5. Remove O-ring from inside assembly.
6. Remove O-rings (P and T), spring (S), and check
valves (Q and R) from check valve assembly.

UNLOADER REMOVAL

1. Remove brass adjusting cap (A) by turning in a
counterclockwise direction. See figure 15, page 20.
2. Remove exposed pressure spring (C) and spring
retainer (D).
3. Use an 19 mm wrench to remove piston retainer
(E) by turning in a counterclockwise direction.
4. Use needle nose pliers to remove piston stem and
valve assembly (H - M).
5. Separate piston stem (H) from valve (M). Secure
the valve near the valve retainer (K). Insert a
screwdriver into slotted head of piston stem (H)
and unthread from valve.

PLUNGER CHAMBER REMOVAL

1. Remove low pressure seal (A) and seal case (B)
from each plunger rod. See figure 9, page 18.
2. Use a screwdriver to pry out the low pressure seal
(A) from each seal case (B).
3. Carefully insert a small screwdriver or pick under
the O-ring (C) and roll the O-ring off each seal case
(B).
4. Pressure seals (A and D) can be easily removed
from each seal chamber by hand or with reverse
pliers. Depending on the model pump, you may
need to also remove V-Packing (Not Shown) and
male adapter (E) from each seal chamber by hand
or with a reverse pliers.
15