Description

Foster Filler Valve Piston

with O-ring and Dowty Washer

The Foster filler Valve Piston is used in all Daystate PCP air rifle models manufactured from circa 1996/7 which feature a Foster-type fill connection. The piston fits inside the male section of the Foster lock fitted to the rifle.

Valve Maintenance

Filler valves are often the source of slow air leaks. Over time, general wear and tear or dirt ingress can cause the seal to become less secure. While the male Foster lock on the rifle should never wear out, the seal of the piston inside it can with use. So it is necessary to replace it from time to time. We also recommend that the Dowty Washer which provides the air seal between the rifle and the male Foster is routinely changed.

Note: Generally, the piston does not wear out, only the O-ring. However, due to the importance of a high-tolerance fit, refitting this O-ring is difficult. Therefore, we offer the whole piston assembly as a replacement part.

Fitting

Fitting the Foster Filler Valve Piston and Dowty Washer is straightforward and can be done by a competent DIY enthusiast. However, working with high-pressure air guns can be dangerous. So if you do not feel confident, we strongly recommend taking your rifle to an authorized Daystate Service Center.

If, however, you wish to carry out the work yourself, we have a number of maintenance resources in the Workshop Guide section of our website, including step-by-stop video tutorials.

What is provided

This part comes with a Filler Valve Piston, complete with pre-fitted Urethane 006 – 2.9 dia. x 1.78 O-ring. The assembly fits inside the male Foster lock. Also included is a Dowty Washer to seal the valve threads.  The male Foster lock and valve unit are not included.

The males section marries to the female Foster connector. We now have the long-reach versions of these available in our webshop, here.