Brake Caliper Elastomer and DOT 5

[Mark L.]

We are all aware several of the major brake caliper rebuilders warn against using DOT 5 fluid. Last year I conducted FTIR testing on several DOT 5 samples finding there is very little difference among the brands. Earlier this year Pat Boyd conducted an experiment on the elastomer. Both results were published on this forum.
I recently had Pat's and my samples tested using an FTIR method. Attached is a more detailed explanation. Bottom line is the EPDM peroxide cure elastomers are not effected by DOT 5. I just rebuilt my calipers using the EPDM o-rings.

[Gary B.]

Re: Brake Caliper Elastomer and DOT 5

As did I.

Gary

[David H.]

Re: Brake Caliper Elastomer and DOT 5

Mark & Pat

Thanks for your efforts sorting this out!

Dave

[Edward J.]

Re: Brake Caliper Elastomer and DOT 5

Mark, do master cylinder seals and rubber hoses come into play with Dot 5?

[Mark L.]

Re: Brake Caliper Elastomer and DOT 5

Mark, do master cylinder seals and rubber hoses come into play with Dot 5?

Ed,
You can see on the attachment that two elastomer components from a M/C were also tested by Pat and me. Both appear to be EPDM and are OK. Gary B. provided these samples and may comment on the source of them.

[Larry M.]

Re: Brake Caliper Elastomer and DOT 5

Interesting information..................

Special thanks to Pat and Mark for their continued work on this issue. Lone Star and the other Corvette caliper rebuilders need to get their o-ring specifications and quality checks under better control. Hopefully this will occur soon.

Typically orange color of o-rings indicates some type of silicone rubber. Silicone will definitely not hold up with DOT 5.......and may also have problems with the other DOTs.

Larry

[Gary B.]

Re: Brake Caliper Elastomer and DOT 5

Mark, do master cylinder seals and rubber hoses come into play with Dot 5?

[Patrick B.]