Supplement for world series pump maintenance – wt – Hale SMR-U User Manual

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Supplement for World Series Pump Maintenance – WT and WS Models

Mk 3 Piston Primer (One piece piston) fitted to -

WT Models from Serial number 2000

WS Models from Serial number 9000

Disassembly/Assembly instructions for the piston assembly, part number 56960/06.

1. The piston assembly fitted to these models is a one-piece unit which is held in position by the

return spring. A spring retainer and a pair of split collets retain the spring against the end of
the piston rod.

2. To release the piston from the cylinder it is necessary to depress the spring retainer and the

spring below, but not the piston rod, this will then release the pair of split collets securing the
spring retainer.
A special tool is available from Hale Products Europe to assist with this procedure.

Spring retainer

Split collets

Spring

One-piece piston

Press on the spring retainer to release the split collets and the
spring below. When the spring is removed the piston can be
pushed from the cylinder

Reassembly of the piston to the cylinder is a reversal of the disassembly procedure.

Maintenance of the piston rod seal components is the same for both types of the piston primer.