61
Part 3 - Inspection
Seals, O-Rings, and Gaskets
Replace seals and gaskets during the reassembly process.
Seals
Each of the three (3) pump pistons pass through seals in the
pump crankcase, spacer plate, and head. Figure 6.13 shows
the orientation of each of these seals.
The oil seal in the pump crankcase is oriented with the
groove towards the crankcase. If you see the internal spring
when installed, the seal is installed backward.
The high-pressure seal in the pump head is oriented with
the flat surface and writing visible. If you see the grooved
surface when installed, the seal is pressed in backwards.
Remember that the bearing ring is installed in the head
before the seal is pressed in.
Check Valves
The check valves used in the pump illustrated in this chapter
are the same for the inlet and outlet, as shown in Figure
6.14.
Earlier pump models used inlet check valves different from
outlet check valves. Be sure to observe the type of valve as
they are removed so that proper reassembly can be
performed.
Replacement check valves and o-rings are provided in the
seal kit.
Head Gasket
The head gasket is installed between the pump head and the
spacer plate. Different versions have been used (two are
seen in Figure 6.15), but the current gasket will replace all
previous gaskets. Replace the gasket each time the pump is
reassembled.
Section 6 • Medium Frame Pump
Portable Pressure Washer Familiarization and Troubleshooting Guide
Item
Name
1
Pump head
2
Bearing ring
3
High pressure seal
4
Spacer plate
5
Low pressure seal
6
Pilot spacer
7
Oil seal
8
Crankcase
9
Piston
Figure 6.14 — Typical Check Valve
Figure 6.15 — Two Types of Head Gaskets
Figure 6.13 — Piston Seals
