GIANT PUMPS P55W Repair Instructions

P55W/P56W/P56W-HK/P56W-0011/P56W-0021/P56W-0121
NOTE: Always take time to lubricate all metal and nonmetal parts with a light fi lm of oil before reassembly.
This step will ensure proper fi t, at the same time protecting the pump nonmetal parts (i.e., the elastomers)
from cutting and scoring.
1. With a 22mm socket, remove
the three discharge (43)
and three inlet (41) manifold
plugs. Check o-rings (42 and
44) for wear and replace as
necessary.
4. Drain the oil from the pump.
Turn the pump over to
remove the four manifold
stud nuts (46) with a 17mm
wrench.
7. Turn the manifold (29) over.
Using a 15mm socket, tap
out the v-sleeves (31/31A-
for P56W-HK), support rings
(32), and pressure rings (30)
through back of manifold.
Repair Instructions
2. Remove the discharge
spring retainer (34), valve
spring (35), and valve plate
(36).
5. Tap the back of the manifold
(29) with a rubber mallet to
dislodge, and slide off the
pump.
31
(P56W-HK only)
30
8. Inspect and clean the manifold (29) and pressure ring
(32). Reinstall the pressure ring (30) with the groved side
pointed towards the front. Insert v-sleeves (31/31A), sup-
port ring (32), and pressure spring (33) into the manifold.
8
3. Using a small slide hammer
remove valve seats (37) from
manifold (29). Inspect valve
plates (36) and valve seats
(37) for wear. If excessive
pitting is seen, replace the
worn parts. Check valve seat
o-ring (38) for wear and re-
place as necessary. Tighten
manifold plugs (43) to 52
ft.-lbs. (70 Nm).
6. From the front inlet valve
ports, remove the inlet valve
assembly (34-40) and pres-
sure springs (33).
31A
32 33