68
Check Valve Assembly
Refer to Figure 6.30 for this assembly.
1 Lay the pump head on a flat surface so that its machined
surfaces are up.
2. Press the thermal bypass actuator into its recess in the
pump head.
a. Check that the actuator is fully seated.
b. Make sure the small actuating stem is installed into the
actuator. Petroleum jelly may be used to ensure that
the actuating stem stays in place for the remainder of
the assembly process.
3. Install the three (3) inlet check valves:
a. Align a check valve with its bore in the pump head so
that the o-ring end is up.
b. Push the check valve down into the head until it seats.
The valve will be just overflush with the surrounding
machined surface.
c. Install the two remaining inlet check valves in the same
manner.
4. Install the three (3) outlet check valves:
a. Position the pump head so that the outlet check valve
ports are up.
b. Install an o-ring seal into the bottom of each check
valve port.
c. Align a check valve with the port so that the o-ring
end goes in first.
d. Press the check valve into the bore.
e. Ensure that an o-ring is installed on an outlet port cap.
f. Hand thread the cap into the port containing an
installed check valve.
g. Tighten the outlet port cap to the torque value
specified in the Torque Chart, found on Figure 6.2
(Exploded View) at the beginning of this chapter. Note
that final tightening is best performed after the pump is
completely reassembled.
h. Repeat steps e to g to install the two remaining outlet
check valves.
Section 6 • Medium Frame Pump
Portable Pressure Washer Familiarization and Troubleshooting Guide
Item
Name
1
Outlet check valve port cap
2
Cap o-ring
3
Check valve
4
Check valve o-ring
5
Pump head
6
Thermal actuator stem
7
Thermal actuator
Figure 6.30 — Check Valve Assembly
