5 • Service
Doc. 065215-02 9/09
83
d. Pull out the piston. The top of the seal should
be flush with the surface of the spacer.
e. Press the seal holder onto the spacer.
To remove the old piston seal from the head:
1. Fill the head cavity with deionized water by injecting the liquid through the
piston opening.
2. Reinsert the piston approximately 3 mm (0.125 inch) into the seal.
3. If this is the
primary
pump head, install a 10-32 fitting plug (P/N 042772) on
the outlet check valve. Tighten the plug.
4. If this is the
secondary
pump head, install a 10-32 fitting plug (P/N 042772)
in both the inlet and outlet ports. Tighten the plugs.
5. Push the piston into the head. (This should hydraulically unseat the seal from
the head.) Remove the piston and pull off the seal.
NOTE If the piston seal is not removed, make sure the 10-32
fitting plug(s) are tight and add more water. Make sure
the head contains no air bubbles, and then repeat Steps
6. Remove the 10-32 fitting plug(s).
The piston backup piston seal is made of soft plastic. Do not press on
the seal with anything hard or sharp, including your fingernail. If the
seal is nicked or gouged, it will not seal properly and may result in
leaks.