PDWA issue

[ianfox]

My PDWA switch has started weeping, and I'm not too sure how I fix it? It appears the PO has installed a fibre washer, probably to address it in the past. It's got me confused as to how it comes apart? I can't imagine a plastic fitting is exposed to the full hydraulic pressure of the system, but there must be fluid behind it because it's weeping? Can I remove the switch without introducing air into the system?
Might a new washer seal it? or are the switches know to fail?

IMG_3696.jpg

[DJT]

There shouldn’t be any brake fluid behind that switch. There are 2 o-rings on the shuttle valve. I think you will find one or both are leaking. It’s a strip down and rebuild job. Fairly straightforward, but a complete brake system bleed afterwards.

[ianfox]

Thanks Dave. Is there anything special about the o-rings? If I knew the size, could I find a replacement here without having to wait for them to ship from the UK?

[barkerwilliams]

Ian,

try this for guidance:-

http://www.zen11896.zen.co.uk/vixen/parts/pdwa.html

Alan

[ianfox]

beautiful, thanks Alan.

[sujitroy]

Use compressed air to get the piston out. Simple job. The one used on the Stag is not as complicated as the one in the link.
Sujit