66
3. Piston assemblies have an integral spring retainer ring.
Install the small end of the tapered spring so that it
contacts the spring retainer, as seen in Figure 6.25.
4. Apply a small amount of SAE 80W90 oil to the lip of the
oil seals and the piston surface.
5. Install each piston through the spring, crankcase, oil seal,
and pilot spacer, as shown in Figure 6.26.
6. Install the thermal bypass piston and spring into the
socket cast into the upper portion of the pump crankcase,
as shown in Figure 6.27. A small amount of petroleum
jelly will hold these parts in the crankcase during
subsequent assembly tasks.
Section 6 • Medium Frame Pump
Portable Pressure Washer Familiarization and Troubleshooting Guide
Item
Name
1
Crankcase
2
Thermal bypass spring
3
Thermal bypass piston
4
Thermal bypass o-ring
Item
Name
1
Return spring
2
Pump crankcase
3
Piston oil seal
4
Pilot spacer
5
Piston
Item
Name
1
Return spring
2
Piston
Figure 6.26 — Piston Installation
Figure 6.27 — Thermal Bypass Spring and Piston
Figure 6.25 — Return Spring Orientation
