24 replies to this topic

[Carlos W]

Couldn't find a replacement for the double-lip O ring that sits between the two chambers so i gave it up as a bad idea.

 
I have never seen these valves.  Is there any chance you have a picture of them taken apart and showing the seal?

If I can find a way of getting the crimped cap off.

[Carlos W]

Ok, I've ruined the cap removing it, as I couldn't be bothered to make a tool, some sort of screwdriver with the end bent over 90 degrees so that you could push the crimp out would be ideal

 

The corrosion inside the unit would've eaten the seals apart in no time so I'm glad I took the advice of the people on here.

 

 

 

 

 

[dklawson]

Thanks for the pictures.  They are very informative.

[Carlos W]

Thanks for the pictures.  They are very informative.

 

do you need any more Doug?

[dklawson]

No thank you.  Those valves were not on the cars originally imported here but I have seen them on later cars.  I was curious if it would be possible to make any new parts required to use commercial EPDM rubber seals.  I have had to do that with a couple of PDWA valves.

 

Thanks again for the photographs.

[tiger99]

Just a little point, but the double lipped seal is NOT an O ring. These have a circular section (hence the O)and are readily available. Double lipped seals are somewhat specialised. Calling it an O ring can lead to all sorts of confusion.

 

I would be interested in knowing who makes single and double lipped seals etc, and especially in materials compatible with either of the types of Citroen fluid, as well as DOT4. That will be 3 different materials, I would imagine. Also, how do they make them? Not just moulded, as far  as I can tell. A reliable source of seals for rebuilding all sorts of classic stuff would be welcomed by many.

[Spider]

They really are a crap thing - on every level!

[Itsaminithing]

They might not be the best design in the world -but they do what they are supposed to do ie: acting as a variable bias valve & stopping the rear wheels from locking up before the fronts no matter what the speed -but i do wish they could be rebuilt easily. At least they're readily available unlike some Aussie built cars that had units with more connections than the UK version.

 

I'm a little confused as the smaller seal on my shaft was double lipped (& i couldn't find a source), whereas the one in the photo looks like a standard O ring - unless it's all the gunge on it that makes it look like that.... or is that the double lipped seal hiding inside the bore?

Edited by Itsaminithing, 01 March 2016 - 09:20 PM.

[Carlos W]

I can clean it up and take some more pictures.

I like the bleed nipple on the ozzy one, I wonder if it'll make bleeding any easier?

[dklawson]

I cannot tell from the pictures but the lobes on the double lipped seal look somewhat like what are commonly called Quad-Rings or X-rings.  (Image below).  I have used Quad-Rings sparingly in some of my designs but in most instances they are not justified.  

 

Most "universal" brake rubber today is made of EPDM.  EPDM is resistant to DOT-3, DOT-4, DOT-5.1 and of course DOT-5.  I know Quad-rings are available in Nitrile and Viton (neither are compatible with brake fluid).  I have not seen Quad-Rings in other materials.