''89 MM Brake Master Cyl. Repair

[jdmckay]

Hi guys!!!

I have a leak between my master cylinder reservoir and the cylinder body. There is an -0- ring connecting the 2, a only takes a little wiggle to see fluid leaking here. Looks like there's on screw on the cylinder holding the reservoir on.

Anyone tried repairing this... hints or suggestions, or knows size of that -0- ring?

And... if i can't match it, what do you think about disassembling and sealing the existing -0- ring with RV silicone?

[t97]

I can't say for sure what size the o ring is but you can go to any parts store and buy a box of assorted o rings for less than 10 bucks. I know you won't need that many but next time you'll have them and saves a trip. Ithe probably could be fixed with rtv but I'm not sure how long it would how up against brake fluid.

[geezer101]

I would not recommend using any form of sealant in any part of the braking system. A wayward chunk of RTV silicone or teflon tape would easily block a relief valve or a port somewhere - say goodbye to brakes and hello to solid objects :slap:

[pennyman1]

that is more like a set of seals, not just O-rings. I had the same issue years ago and could not find the seals anywhere - they are all over eBay now.