dot 5 silicone brake fluid

[patriot68]

can i use dot 5 brake fluid in my 68 camaro for brakes and clutch?. my brake and clutch systems are completely new..calipers/lines/master/slave....i would hate to ruin my paint if regular brake fluid spilled on it. thanks
scott

[orange88]

dont quote me on this but i think you need diffent seals in everything

[kennyd]

i run dot 5 in everything i build new . and never had any problem

[patriot68]

thanks..

[XcYZ]

How much heat can DOT5 take? I've heard all kinds of stuff, but it's all over the board.

[Blown353]

Originally Posted by XcYZ

How much heat can DOT5 take? I've heard all kinds of stuff, but it's all over the board.

DOT5 (silicone-based) fluid by itself is OK in terms of the boiling point... the bad part is it's hydrophobic (i.e. repels water) and because of the density difference all the water collects in the lowest parts of the system (the calipers) therefore you have all the water concentrated at the hottest point in the braking system. That's bad. Might as well consider your boiling point to be 212F or thereabouts depending on altitude because once the calipers heat up it will flash the water that is puddled in them.

It's not a matter of if water will get into your brake system but how much water is in your brake system and how much more is added every day.

DOT 5 likes to aereate and become "spongy", it's tough to bleed, not to mention the water issue is the nail in the coffin. It's great for show cars that only need their brakes getting on and off the trailer but that's where the goodness ends. The only redeeming quality to the stuff is that it does not eat paint and that does not at all outweigh all the other major issues with the stuff which are ALL safety related.

Don't confuse it with DOT 5.1 though, that is a totally different animal.

Use good DOT 3/4 or newer 5.1 fluid (I like ATE Typ 200 / SuperBlue) and change it occasionally and things will be OK.

Good reading here: http://www.stoptech.com/tech_info/wp...fluid_1a.shtml