Can anybody give me a recommendation for the type of brake fluid I should use? This will be for a street/strip '68 El Camino. The car has power brakes with drums out back and 12" rotors with aluminum calipers up front. I'm putting these brakes on now, so all fluid is being replaced. Any recommendations are greatly appreciated.

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Greg
'68 El Camino
Simi Valley, CA
Greg's Page (http://home.pacbell.net/kazuaki)

[This message has been edited by kazuaki (edited 04-10-2000).]

Depends upon the useage of the vehicle. I like to use Dot 5 Silicone fluid since it does not absorb moisture and cause rust in the master cylinder and calipers. For an occasional use car this is the best. for a daily driver car some people like to use standard Dot 3 or 4 fluid, but personally I always use the Dot 5 Silicone. We even put the DOT 5 in all the forklifts that we manufacture here at work, it is the only brake fluid that meets the Mil Spec.

Ditto. And although some say it doens;t work as well, its been fine for me. Doesn't screw up paint as bad either.

Bob,
The reason for rust developing in the master cyl. or caliper pistons is due to the water. The fact that DOT-5 fluid is NOT hygroscopic (yes, that spelling is correct for absorbing water) is all the more reason NOT to use it in anything that requires the extra boiling protection and/or in the situation where you are changing the fluid often (i.e., road race car). You don't have to worry about the paint if you just wipe it off if you spill. DOT-5 is NOT recommended for most folks.

Chad;

I don't quite understand what you're meaning.
Dot 5 doesn't absorb water which makes the system more rust resistant. The Dot 4 and lower fluid will absorb water which rusts out the system.

Any absorbed water also lowers the boiling point since the different brake fluids boil at something like 350 degrees or higher while absorbed water boils at 100 degrees. The Dot 5 lists the highest boiling point of them all and doesn't absorb water.

Of course you're correct about not using it if you're changing fluid a lot. But, the boiling point is higher for Dot 5 so it could help in a race car that sees heavy brake usage.

I'm probably going to put it in everything I work on from now on. I'm sick of pulling the system apart because rust in the cylinders causes them to leak or the pistons to stick.

Just remember that it's not compatible with the lower fluids so don't mix them.

Peter

We put Dow Silicone Dot 5 brake fluid in every forklift that we manufacture for rust prevention. We have taken them apart afer 15 years of outdoor use with no rust whatsoever in the system! You would have to have a way for the water to get in for it to puddle in a cylider.