I had always heard good things with silicone brake fluid. I went to do my system and my friend who owns a Corvette restoration shop told me not to use it. He is usually right about these things, so I went with regular fluid. Who uses silicone brake fluid, how long have you used it, and have you had any issues?

You're better off not using silicone fluid, especially in a car that had regular DOT 3 fluid in it. Silicone is great for museum cars that don't get driven, but rare is the performance car that specifies it for use.

Silicone fluid displaces water, and it is very difficult to bleed the old fluid out that it will replace. If the old fluid is not completely removed, it can aerate and make bubbles in the system, resulting in very spongy brakes under hard use.

You are much better off using DOT 3 fluid and flush it annually. I've read that most NASCAR teams use Ford DOT 3 fluid as it's supposedly the best brake fluid available, and they simply tape over the brand name, but I don't know that for a fact, but I have read that.

I have an '02 Lincoln LS V8 Sport and it specifies DOT 3 only and under no circumstances is DOT 5 silicone fluid recommended for the car.

Unless you have a trailer queen, stay away from silicone fluid.

I switched to dot5 along time ago and jave had no problems at all. I don't know that there is any big difference with either as long as you maintain your system the way it is meant to be. I don't think I would worry about it and stay with the dot3

Standard DOT 3 tends to absorb water. That's why old fluid gets dark. It starts to rust and corrode the system from inside out. If the system is flushed every year or two, this is not a problem, and the brake system is fine.

DOT 5 silcone fluid does not absorbe water. It can sit for many years and not gather water, therefore does not need to be changed to keep the system clean, and lasts a very long time with no damage to the system. BUT>>> it does tend to absorb air. This can make it difficult to bleed. It won't do this in a sealed system, so it is not a problem once in the system. The problem is it's heat range and boiling point. It is much lower than DOT 3. In normal use, not a problem. If you are going to race, drive in mountains, tow trailers, or anything to make the brakes hot, DOT 5 is not a good idea. It boils earlier and causes the brakes to fade.

You CANNOT mix the two. They boil at an even lower temp. They can get contaminated very easily, they sometimes gel. Mixing at best makes the brakes perform poorly, at worst they dont work at all. Change over either way requires very through flushing.

I use DOT 3, take your choice.

Ken Styer

After replacing rear calipers because they were pitted so bad from internal rusting that they leaked, I switched to silicone which does not absorb water and has 500 degree F boiling point. Never had any problem bleeding but I did completely flush the old fluid. Haven't had any problems since and the fluid hasn't discolored. Good luck with whichever way you go.

Marc

I've used silicone in two cars now, 68 Vette and 74 TR6. Love it. Friend of mine put it in an old army jeep and it leaked, as it is thinner. If your system is good, I'd go with silicone all the way. After all, all our cars are vintage and usually don't get driven that much. All the better to use something that doesn't absorb water. Pretty purple also!!!!!

Mark

I have used silicone fluid in my 78 for nine years
with no problems!
Steve

My 1971 has had silicone brake fluid for five years and a half with no problem so far.

Is there anyway to tell synthetic from Dot 3? I'm still trying to figure out what the previous owner did.

The silicone fluid is a purple color. DOT3 or DOT4 is clear. If it is turning brown, it's dirty clear fluid.

Ken Styer