Compatibility of brake parts rubber

[russcc]

The pros & cons of DOT 5 have richocheted around here for awhile. What I haven't been able to find out is if DOT 5 is compatible with the rubber in 25 year old NOS wheel & master cylinders. Anyone have the facts. Thank you Fordbarners.

[alanwoodieman]

YES it is and I have had Dot 5 in my 40 wagon since 1990 when I had to buy it at the honda motorcycle dealer. got curious last year and pulled the wheel cylinders/master cylinder and they were as nice as the day I put them in the car.

[STEVE O]

Hi, I posted a little info in another post about the silicone vs rubber. I switched my 50 Ply. to silicone in the late 80s. I overhauled all 4 wheel cylinders 26 years later and put silicone fluid back in again and is still going. I was told then about the problem that the silicone can attack the rubber. In all my reading it only attacks the old pure rubber (that have different elastomers) cups that are for the most part all gone. So considering what you and I done in the late 80s-early 90s with the cups we used then I don't think anyone will be using cups now that would cause a problem. One tidbit I did read was on bigger trucks where you used hydrovacs once they start leaking and your engine vac. pulls the the silicone brake fluid into the engine once burned it make silica sand thus internal engine damage.
Steve

[russcc]

Thank you Fordbarners for the personal real world experiences, Good to know.

[Kurt in NJ]

I tried it in my MG, after the third clutch master failure I switched back, no more failure during my ownership---plus the clutch pedal movement didn't feel normal, it was sort of rachety

[J Franklin]

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Originally Posted by Kurt in NJ

I tried it in my MG, after the third clutch master failure I switched back, no more failure during my ownership---plus the clutch pedal movement didn't feel normal, it was sort of rachety

Did you ever analyze what was causing that failure? I doubt it could have been the brake fluid if all was perfectly clean.

[STEVE O]

Kurt you bring up some bad memories for me. I owned a 1985 Jeep Cherokee with a Renault diesel engine. Wonderful jeep, sold it @281 k miles but the clutch master cylinder would go bad about every 1 to 1 1/2 years. Installed several new clutch master cylinders and installed several kits. One of my kits was a lucas kit. It had red grease with it????? I always used Raybestos assembly lube or the little tubes that use to be with kits. Against my better judgement I coated the bore with the red grease. 3 Months later pedal sticks to the floor. Pull it apart WOW cup swelled up terrible. Still don't know what the red grease is for in the master and w/c kits unless its lube for the brake shoes?? I blabbered on enough.
Steve

[Aarongriffey]

I fished the clutch and brake systems on my MGB wheel got it in 2008.
I have not had any hydraulic problems any have converted maybe five or more MG cars over to DOT5. But, as I have said before I never use DOT5 unless all the cylinders are new, not rebuilt but new.
My 1951 F1 has had the same old DOT5 in it since 2000.
Never has caused any problems.

[Kurt in NJ]

I remember some Jeeps had Girling clutch system, after working on european cars I learned regular american car brake fluid swelled girling rubber,used only fluid that says "safe for girling systems" in them, but the lockheed systems didn't care

I solved hydraulic brake leakage problems by selling the 39,46, have model A, and 36 because they have never leak mechanical brakes