Brake Fluid

[Len M.]

Any thoughts on using Dot 5 brake fluid for my '65? Pros, Cons???

Thanks, Len

[William F.]

Re: Brake Fluid

Lots in previous threads. General consensus is don't.

[Jim L.]

Re: Brake Fluid

Lots in previous threads. General consensus is don't.

Not here it's not. I've been using DOT5 for almost 40 years and it's the only brake fluid I'll put in the systems of my old cars. I've even gone road racing with the stuff. Never a problem.

To the OP, best to do your own research and draw your own conclusion.

[Mike M.]

Re: Brake Fluid

i agree with jim. i put dot 5 in a 65 and a 57 in 1971. they are still there and no problem. the old "Farm Use" corvette that i autocrossed with no mercy, had DOT 5 and no problems in the 11 years i ran the old girl. it looked like a 61 but the drivetrain/frame was a 92 ZR1. all our other c-1 and c-2's use dot 5. mike mike

[Patrick H.]

Re: Brake Fluid

all our other c-1 and c-2's use dot 5. mike mike

Mike,

Where did you get your calipers?
I'm having a heck of a time with leaking calipers on a 77, even with two new sets of seals. The owner wants to stay with DOT5 if at all possible.

My next step is O-ring seals to see if that helps.

Patrick

[Bruce B.]

Re: Brake Fluid

I have a 57 and a 62 and a 65 all with DOT 5.
Never a problem for years and years.

[William F.]

Re: Brake Fluid

Well, maybe I was wrong but thought on a long previous thread it was said Corvette Stainless Steel Brakes said DOT 5 would void warranty on their calipers. True or urban legend??

[Jim L.]

Re: Brake Fluid

Well, maybe I was wrong but thought on a long previous thread it was said Corvette Stainless Steel Brakes said DOT 5 would void warranty on their calipers. True or urban legend??

They may have said that. And there is persistent folklore about the composition of the fluid having changed. No one has done good science to verify that folklore, however.

Bottom line for me is that I'm sticking with the stuff because I've had 100% success for several decades.

YMMV....

[William F.]

Re: Brake Fluid

On further reading, seems its the 5.1 fluid that may swell O rings, not DOT 5.0 silicone brake fluid. What did you users of silicone fluid flush your brake system with before going to silicone fluid?

[Mike M.]

Re: Brake Fluid

corvette stainless brakes in Clarence new york supplied the calipers for the 65 back in the 70's. haven't used them for about 30 years and not sure they are still in business. recent calipers from lodestar. regards, mike

[Harry S.]

Re: Brake Fluid

I have two 63's both with power brakes. I like the feel of the brakes with DOT 3. The one with DOT 5 seems to travel too far before it slows/stops.

[Mike M.]

Re: Brake Fluid

I suspect you have some air mixed in with the DOT 5. mike

I have two 63's both with power brakes. I like the feel of the brakes with DOT 3. The one with DOT 5 seems to travel too far before it slows/stops.

[Harry S.]

Re: Brake Fluid

I suspect you have some air mixed in with the DOT 5. mike

Mike, that's what I thought. I changed the Master Cylinder, P/B Booster, a wheel Cylinder then bled them 2 times and no change. I'm stumped.

[Mike M.]

Re: Brake Fluid

air bubbles are enveloped by DOT 5 IF the bake fluid is dumped into a master cylinder. I gently and slowly and obsessively pour the DOT 5 fluid down the sides of a plastic funnel, the tip of the funnel pressed against the bottom of the master cylinder. once I have the cylinder filled, I get a neighbor who smokes cigarettes to come by and blow the smoke directly on the exposed DOT 5.
If one pours the DOT 5 haphazardly into the cylinder, one can view a multitude of tiny air bubbles entrapped in the fluid.
The method of bleeding the brakes can also make for air in the system and to avoid this, I always pressure fill the system( as opposed to vacuum at the wheel cylinders.) mike

[Philip C.]

Re: Brake Fluid

Hi Len the biggest PRO to Dot 5 is if you have a restored or nice original car etc and have a problem with anything in the brake system ie; hose, lines, wheel cylinders, calipers, master etc and the fluid leaks or you have to replace anything you will have no damage to anything that's painted. NOT SO WITH Dot 3 you have a big problem. Plus Dot 3 is hygroscopic so it draws moisture. The brake guys out there Lone Star and other don't like Dot 5, (but they sell brakes for a living) I have found also what Harry S has been experiencing the dot 5 brake pedal on a power brake car is a little "spongy" compared with to Dot 3. Mike M has got some good methods but I think he's the one Blowing smoke (lol) Use "O" Ring not lip seals type calipers. Phil