I have serched the forums and was wondering if there are any new thoughts on which brake fluid to use. I will be using all new parts on my brake system (1950 F1). It will be stock except for a dual master cylinder. Once complete (several years down the road) the truck will be stored winters and driven less that 1,000 miles annually. At first I was leaning toward DOT 5 fluid but after reading past posts I am now planning on using DOT 3. What do you think?

 

As much as it will be sitting use the Dot 5 or you will be replacing wheel cylinders every other year. I'm currently using Dot 5 in my 48 F-3 which I finished (mechanically) in 2006. I've had absolutely no problems with it so far and it sits from November to May every year. I'm totally sold on it and will be using it in my 49 F-1 also. Before the trucks I used it in a 65 Mustang for about 5 years before I sold it and no problems with that system either. It's more expensive but it's good stuff...

 

Hello,

I'm using Dot5 in my 52F1. I replaced everything in the braking system so it was a good time to switch. I did this in 2007 so far so good. For longer term usage I have Triumph Stag with front disc and rear drum that I redid the brakes completely on in 2000 and switched to silicone then as well, I've flushed the system only once in that time and have had no failures using it either, I think the key is to start with a clean, new system with no trace of the old style brake fluid.

Good luck.

 

DOT 5 is a far superior product as I understand it. Fully synthetic and does not absorb moisture from the atmosphere like DOT 3. As stated, do not mix with DOT 3.

 

.....Dot 5 in everything I own.

 

DOT 5 is a race only product. It doesn't absorb moisture like DOT 3 or 4 does. Just use DOT 3 it's not like your going to see high enough brake temps to boil the fluid.

 

D.O.T. 5 Brake Fluid
Here, form your own opinions..

 

I used DOT5 in my 53 when I built it. The brake system was finished long before the truck was ever running and have had zero problems. It does take a little getting used to the slightly softer pedal feel, but it really isn't much.

 

I don't think I've ever heard DOT 5 referred to as a "race only" product. I think it's being used in new Corvettes and possibly other cars. It's the buildup of moisture in the system over time that causes all the havoc in brake systems. If you can avoid the moisture absorption associated with DOT 3 you won't have to rebuild or replace wheel cylinders and/or calipers as often. For the most part brake fluid temperature is a non-issue...

 

That was a very helpful link. I was going to say "DOT 5" but now I'm not so sure.

 

I don't know anything about the person who wrote this article but his statement "silicone is the highest maintenance of all brake fluids, one that demands frequent attention" based on my experience is pure garbage. My 1965 Mustang was converted to Dot 5 and I drove it 5 years with no attention to the brake system whatsoever...didn't even have to add any fluid during that time. When I sold it, the new owner continues to drive it and he has also done nothing to the brake system and that's been at least three years more. My 48 F-3's DOT 5 brake system was finished in 2005 and I started driving it in 2006. I have yet to do anything to that system either.

 

Dot-5 conforms to federal motor vehicle safety standards No. 116 Mil-B-46176. Will not absorb moister. Lubricates moving parts. Will not harm painted surfaces. Brake performance will improve with better low temp pedal response. Corrosion resistant. ( On the bottle)

I've been using Dot-5 for many years in 1965-1982 corvettes. They have a history of corrosion with Dot-3. Corrosion was so bad many had stainless sleeve inserts pressed in the brakes. I've taken brakes off wrecked vettes and disassembled the brakes, finding no corrosion when Dot -5 was used. You need a good flush before changing to Dot-5 and never mix Dot-3 and Dot-5. I also used Dot-5 in my Harley. chuck

 

Dot 3 for me. I fix brakes everyday at work and see no need to use Dot 5. I've had to fix many vehicles that have had their brake systems contaminated with oil and Dot 5. It's a costly venture with new vehicles as EVERYTHING has to be replaced.

Brake fluid is also supposed to be flushed every two years. It absorbs moisture and colour from the rubber seals. Moisture gets into all brake systems regardless of fluid type and it is much easier to flush out with glycol fluids.

Also most replacement brake system components come prelubricated out of the box with Dot 3 fluid.

 

What is all this crap about dot 5? I've use dot 5 since 1981 in all that time did I ever experience any problems mentioned in this thread with this stuff other than the benifits mentioned. IMHO the benifits out weight the negitives.