Vette(s): 1969 convertible L71 427/435 4-speed black interior
DOT 5 silicone fluid is in no way compatible with DOT 3 or 4, which are mineral based. If they mix a cloudy mess will form and create clogs in the brake lines and calipers.
With all the advantages of DOT 5, in order to use it you have to completely flush and purge your hydraulic system of the brake fluid you have now. I would also replace all flexible brake hoses and seals in the calipers. Otherwise you run the risk of it mixing with any residual brake fluid currently there.
DOT 5 is also notoriously difficult to completely bleed the system of air. In fact, many, if not most, makers of performance cars specifically state not to use DOT 5 fluid. In extreme handling it can bubble and those bubbles can cause spongy pedal.
My own opinion is DOT 5 is great in a museum car or a car that get driven occasionally and gently. I think DOT 3 or 4 is better for most purposes.
There's also a DOT 5.1 which is non-silicone and is backwards compatible with DOT 3 and 4. It should have been given a different designation as it creates confusion.
Your money...your choice.
Poet...Mystic...Soldier of Fortune. As always...self-absorbed, adversarial, c o c k y and in general a malcontent.
Click image for larger pic
Thanks for the details which helps make my decision an easy one!
I will just install the new Speed Bleeder Screws and continue with the DOT 3/4 fluid.
I just bought the '68 in late Oct and the only issue I have is the Brake lite comes on when I push hard on the brakes then goes out. What I've read, the majority lean toward there being air in the brakes and bleeding being the probable fix. I live in CO so the driving is winter limited as far as use.
I'm putting Speed Bleeders on because you can do the process by yourself, as my wife is never around when I need her. I've got the Bleeders and the hose and catch bag, so now with this decision made, I'm ready to bleed the brakes as soon as it warms up a bit.
This shows how valuable this site is. Especially for those of us that are mechanically challenged as they take on the more simplier of tasks
Corvette is a registered trademark of the General Motors Corporation(GM) &
Chevrolet Motor Division. Vette Registries, LLC is responsible for all site content (except for member submitted content or where otherwise
noted) and does not claim or imply that Chevrolet or
GM is responsible for Official C3 Vette Registry content. Vette Registries, LLC is independent from GM and is not affiliated
with, sponsored or supported by GM. Copyright/trademark/sales mark
infringements are not intended, or implied and are in fact used to support
GM, Chevrolet and Corvette.
Official C3 Vette Registry content is Copyright 2001-2017, Vette Registries, LLC. Content may not be reused without written consent. All Rights Reserved. NS
Corvette (Vette) Model Years on this site: 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982