• Hi Guest!
    If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

TR2/3/3A Brake/Clutch Reservoir Seal

Share this page

M

mastaphixa

Jedi Trainee
Country flag
Online
So I have disassembled my brake/clutch reservoir. There is a thin rubber seal that goes between the standpipe for the clutch master and the reservoir. It gets trapped between the bottom of the standpipe and the bottom of the reservoir by the fluid fitting for the clutch master. Does anyone have a good source for that seal? Moss only offers the entire reservoir. I know I can't just use a Buna N type o ring. I'll be using DOT 3 by the way.
Thanks in advance,
Steve
 
Buna-N is the wrong material, conventional brake fluid will attack it. You want EPDM (although EPR and SBR would be OK too). MMC should have something.

Seems to me I found something suitable (in EPDM) in the faucet repair section at Home Depot, but I don't recall the details.
 
Geo Hahn said:
Not an answer, but this page about how Moss dealt with it might give you some ideas:

https://www.mossmotors.com/graphics/products/PDF/582-982.pdf
Click to expand...

Oddly enough, Marco Rubber (who makes such things and should probably know) says that Viton is "not recommended" for brake fluid.
https://www.marcorubber.com/compatibility.htm
(scroll down to brake fluid on the left, then look for Viton on the top)

PS, Du Pont spun off Chemours as a separate company in 2015; Chemours now makes Viton. Their web site says the same thing, Viton is either "severely affected" or "not recommended", depending on exactly which Viton you get.
 
I just got a black washer from Ace. I left it in brake fluid overnight to make sure it wouldn't swell...and went with it. Like $.25
 
My Saabs use those washers Geo showed. They have inside and outside auto trans coolers and without those on my used vehicle the seal is very difficult.
 
Geo Hahn said:
Not an answer, but this page about how Moss dealt with it might give you some ideas:

https://www.mossmotors.com/graphics/products/PDF/582-982.pdf
Click to expand...

My first Moss gold reservoir weeped dot 5 so they replaced it on warranty.
When the replacement also leaked I fixed it myself with no leaks since.
I disassembled,replaced the cupped washers with flat washers and made velum gaskets covered with coppercoat and so far so good.The cupped washers are supposed to hold the sealer and form a seal washer but the cups also limit compression of a new gasket and foil any attempt to tighten up on a weeper.
Tom
 
Great :-( ....I have a new Moss Gold one to install in the Spring...I was hoping to fix the weeping one that I have on there now...

Cheers
Tush
 
All,
I found a solution to my reservoir seal problem. Mcmaster Carr (of course) sells several chemical resistant flat washers. Pn 91367A925 is a Fluorosilicone Rubber that has an inside diameter of .495" and an outside diameter of 1.06 with a thickness of .052' to .072". Pn 94733A725 is a Santoprene Rubber(TPV) with the same dimensions except it is a bit thicker at .068" to .088". I chose the latter. It fit perfectly. The only down side is that I now have 49 of these things laying about. If you should need one send me a pm and I'll see what i can do!
 
Back
Top