minigraf 4 air leak

[langland]

Hi, I have an old minigraf 4 2p. There is an air leak from the silencer port of the first valve (see photo). I have changed the valve but the problem persists. The underpinner works fine, it just doesn't hold its pressure. Any advice would be greatly appreciated.
thanks
matt

[Chris2103]

From previous experience on air brake systems an air leak coming from an exhaust port on one valve all too frequently was caused by a seal leak on another valve. One way to trace is using the plumbing diagram for the air system and then tracing. I know this isn't giving you the direct answer but air leaks tend to be a bit of a treasure hunt.

[Jamesnkr]

Have you changed the silencer (little blue thing), or the valve (big metal thing nearly the size of cigarette packet)?

[langland]

I've changed the actual valve, the cigarette sized one.

[JohnMcafee]

The photo shows a silencer is missing.

Does the leak persist even when the silencer is replaced?

[langland]

Yes it does, I've just spoken to mark at underpinner spares. I've got acouple of things to check tomorrow, but I think we have narrowed it down to a leaking seal in the wedge hammer valve. Thanks for the replies.

[langland]

Just a quick update, leak all sorted thanks to Mark from underpinner spares.He talked me thru everything on the phone and found the fault. Turned out to be a faulty pressure switch diaphragm, top bloke, can't recommend him enough.