96
Spacer Plate
1. Referring to Figure 7.37, install the three (3) low pressure
seals into the bores provided in the spacer plate.
2. Align the low pressure seal bores of the spacer plate with
the pistons protruding from the pump crankcase. With
mating holes aligned, push down on the spacer plate. The
low pressure seal bores of the spacer plate should engage
the pilot spacers.
3. If present in older-model units, install an o-ring over the
two M5-0.80 x 20mm truss head screws. Install and
tighten the two truss head screws into holes provided in
the spacer plate and threaded holes in the pump
crankcase.
4. The inlet check valve seat supports are installed over the
spacer place, as shown in Figure 7.37, with the large
diameter end toward the crankcase.
Pump Head Assembly
1. Install an o-ring and backup ring on all check valves, as
shown in Figure 7.38.
2. To install the three (3) inlet check valves, along with their
o-ring seals, use a 7/16”-20 bolt of sufficient length along
with a nut, washer, and one of the high pressure port
towers, similar to that depicted earlier in Figure 7.15.
a. Thread a jam nut onto the bolt, then the washer.
b. Install the high pressure port tower over the bolt until
it contacts the washer and leaves 4 or 5 bolt threads
exposed.
c. Thread the 7/16”-20 bolt into the female threads of
the inlet check valve. Then use the jam nut to finger-
tighten the high pressure port tower against the valve
backup ring. Make sure the high pressure port tower is
snugged firmly against the backup ring.
Again, refer to Figure 7.15 for a depiction of this
assembly’s appearance.
d. Lubricate an inlet check valve, seal, and backup ring
with silicone spray.
Section 7 • Large Frame Pump
Portable Pressure Washer Familiarization and Troubleshooting Guide
Item
Name
1
Low pressure seal
2
Spacer plate
3
Check valve support
Item
Name
1
O-ring
2
Backup ring
Figure 7.38 — Check Valve O-Ring Assembly
Figure 7.37 — Inlet Check Valve Seat Supports
