Electrovalve O Ring

[DHallworth]

I had the electrovalve off the Activa today and when I got it out I noticed that the green o ring was hard, brittle and had snapped.

Having looked on Citroen Service, the electrovalve is now NFP but they don't even list the o ring separately which is annoying.

Does anyone have a source for LHM resistance o rings or happen to know what size they are? I stuck a generic black one on it which wasn't a good fit but it seems to be holding for now. I'd certainly like to replace it with the right one asap though.

David.

[citroenxm]

Send citro jim a pm david.. he will have all your answers...

[CitroJim]

Send citro jim a pm david.. he will have all your answers...

Why PM me? I'm right here

I have one answer but only for the bigger of the two O rings. That one is the same as the green one under the hydraulic pump piston caps - the ones with the Torx socket in them.

For the baby one the only way is to get a selection of potential candidates and soak them in LHM for a few weeks and see if they deteriorate.

I'd look at small O rings made of Viton and intended for Diesel pump service.

Standard rubber ones as you get in kits from motor factors are not likely to cut the mustard...

[DHallworth]

Jim, you don't have any pictures of one in bits showing the location of the o rings do you?

The little one I replaced but wasn't sure where the bigger one goes.

David.

[CitroJim]

Yes, I'm sure I have David but it'll have to wait a bit until I'm home. It won't be too early as I have to leave work and then immediately pick up my girls for Robyn's birthday do this afternoon/evening but basically the big O ring sits in a groove just under the big hexagon..

Look at my thread where I spoke of how to recover a corroded electrovalve and this should have a couple of pictures...

[CitroJim]

David,

Have a look at this thread...

http://www.frenchcarforum.co.uk/forum/v ... =3&t=41919" onclick="window.open(this.href);return false;

It'll show you where the bigger of the two O rings go in the groove. The first and second pictures...

[Hell Razor5543]

Happy Birthday, Robyn.

[DHallworth]

Thanks Jim, I have actually left that one out altogether! I'll need to measure the smaller of the two and get one ordered and change them both at the same time.

Many happy returns to your daughter

David.

[CitroJim]

That one left out altogether is likely to provoke a leak shortly David... That it is not leaking now must be down to excellently machined and spotless faces on the sphere block and electrovalve body!

Robyn says thanks for the birthday wishes We had an excellent evening out and my wallet took a severe bashing

[Mandrake]

I agree with Jim that most typical black o-ring's aren't up to the job David.

Even if they're LHM safe (which many of them are) they're usually too soft so the high pressures distort them so much that they start leaking after a short time. I had this happen when I tried to put regular o-rings in the Hydraulic pump - they only lasted a few days then started leaking even though the dimensions were the same... The proper seals seem to be made of a much tougher material that resists deformation a lot more and handles the higher pressures. You can clearly feel the difference when pinching them with a fingernail.

If the large seal is leaking (or missing!) it will most likely leak externally. if the small seal on the end by the filter mesh is leaking or missing then it will cause the valve to be very leaky (internally) in the off/hard position, because it seals between inlet high pressure and the control pressure going to the shuttle valve. This would cause the accumulator pressure to bleed away quickly soon after the car is switched off...

[kenhall1202]

A couple of my recommended Viton O rings suppliers are given on clubxm dot co dot uk, unfortunately the site appears to be down today.

See http://www.club-xm.co.uk/forum/viewtopi ... =13&t=3632" onclick="window.open(this.href);return false;

Ken