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9. Remove all traces of the engine adapter gasket or o-ring.
Use a new gasket or o-ring each time the engine adapter
is installed.
Axial Cam Drive Components - (Straight Engine
Shaft)
On units with straight engine shafts, proceed as follows,
referring to Figure 7.8.
1. Remove the axial cam bearing, the axial cam, and the
engine adapter bearing assembly as a unit. Bearings may
be either ball or roller bearing type, depending on the
pump model.
2. Remove the engine shaft adapter, thrust washer and
retainer washer
3. Remove the four (4) 5/16”-24 socket head or button head
cap screws that retain the engine adapter to the engine.
The engine adapter can now be removed.
4. Remove the engine adapter gasket completely.
Pistons and Piston Springs
Refer to Figure 7.9 for this disassembly. The three (3)
pistons along with their springs can be removed from the
pump crankcase by grasping the springs and pulling straight
out.
Newer model pumps have the retaining ring attached
permanently to the piston (upper illustration).
On older models, the springs are retained by spring
retainers and a lock ring. It is not necessary to remove the
spring retainer and lock ring unless they are obviously
damaged and require replacement.
Regulator/Unloader Valve
Referring to Figure 7.10, remove the three (3) M6-1.00
unloader cap socket screws and M6 ribbed lock washers.
Section 7 • Large Frame Pump
Portable Pressure Washer Familiarization and Troubleshooting Guide
Figure 7.9 - Piston Assembly
Figure 7.8 - Axial Cam Drive Components (Units with Straight
Engine Shaft)
Item
Name
1
Engine adapter
2
Roller thrust bearing assembly
3
C-ring cam retainer
4
Washer retainer
5
Thrust washer
6
Engine shaft adapter
7
Axial cam
8
Piston pivot bearing assembly
Item
Name
1
Return spring
2
Piston
3
Retainer
4
Lock ring
Figure 7.10 — Unloader Valve Removal
