Magnum Venus Plastech PATRIOT SSB Auto - Manual (Page 23)

Patriot SSB Auto Instructions Issue 05 30/06//08 Page 23 of 43
9.1 Catalyst pump piston seal.
The Patriot SSB model is designed with a new type of internal Piston valve. This new
design has dispensed with the conventional small ball and spring metal to metal types
formally common in the industry.
In the new design the valve action is generated by the fact that the piston assembly has a
very small amount of “slop” or lost motion.
It is essential therefore that during any maintenance on the piston seal the correct
lost motion is set as detailed below and is observed before re assembly after
service of this section.
To access the pump piston seal or any other internal pump parts proceed as follows.
1 Adjust ratio to maximum
2/ Lift the filter end of the catalyst feed above the catalyst bottle fluid level, operate
recirculation to pump out catalyst from system. Continue to pump until air bubbles appear
in the return flow sight glass.
3/ Remove catalyst feed pipe from the inlet (assy. 0099) and the outlet pipe connection
(6150). The inlet fitting should only be hand tight. Take care to collect or wipe away any
residual catalyst as the fitting is opened
4/ Unclip top and bottom clevis pins to allow pump removal (4279)
5/ Unscrew by hand the lower catalyst block (PS 4282) from pump body.
6/ Unscrew outer tube (PS 0526). The pump cylinder (PS 0525) is now exposed.
Remove this by pulling and sliding off the pump shaft and piston assembly.
7/ Loosen locking nut 6256 and unscrew the piston retainer M4 screw (5692) using 2.5 AF
Allen key The piston assembly will remain upon the screw as it is removed.
8/ Remove the Piston assembly from the screw and unscrew the piston (4234) from the
retainer bush (4235). Withdraw the piston seal (1712).
9/ Replace with new seal. Observe the correct” lip up” orientation of the seal as detailed
on figure 33 below. Do not force seal onto piston (4234) unevenly. Best results are
obtained by placing seal in position (lip upper most) and hand tightening piston and bush
back together. Do ensure assembly is fully retightened. It should measure 13.5 mm
(0.524”) when tightened. Piston valve seal O ring (5684) may be renewed at this time.