Leaking A4 Avon valve

[Spyro]

I have a leaking A4 Avon valve. Nothing appears to be stuck in it. I have tried various remedies including washing up liquid and brake fluid on it but I think the diaphragm is torn. Can the diaphragm be replaced or do I need to replace the whole valve? If so is it possible to replace with a more up to date version. And how do I do it?
I know I can get replacement valves from Polymarine.
Any advice welcome.

 

[StephenSails]

Your best be is to replace with an Avon A7 valve but its really a jobs for the pro's.

 

[savageseadog]

Brake fluid has to be about the least suitable treatment for it.

 

[neil_s]

I don't think you can replace the diaphragm on the A4 valve from the outside. It is feasible to replace the whole valve assembly, though. I did this on my Tinker Tramp, which uses A5 valves, although, as Stephensails recommends, you would be better advised to use the A7 type on your Avon. You will need to cut out the old valve and then provide a patch on the outside and inside of the boat, about 8 inches diameter, well glued with Polymarine 2 part adhesive. You might need to fit the new valve to the inside patch before you glue it to the boat - I had to with the A5 valve, but the more modern ones might be fittable from the outside. Remember to clean the material with Polymarine cleaner before glueing and work over the new patch with heavy pressure to make sure there are no holidays. I think the professionals would stitch the inside patch to the boat, but my Tinker has been in service with its new valve for a year, now, including pumping up to high pressure for sailing - so the glue will hold by itself.

Good luck! Neil