Brake fluid
 

I plan on putting a new master cylinder on my 39ford and also the 4 wheel cylinders what number brake fluid should i use. Also on my flathead 8 what brand oil and weight should i put in the engine what is the best i live on the east coast. THANK YOU JIM S.

Re: Brake fluid
 

You are going to get answers all over the place on these type of questions. Everyone has there favorite! Real close to what is your favorite color.

Re: Brake fluid
 

Do a search on brake fluid and then one on oil. Then plan to spend the night reading all the posts and opinions on these subjects. The search function is your friend.
John

Re: Brake fluid
 

On my 39 Ford, I've been using Dot 5 for the last 25 years. Started using it after replacing all wheel and master cylinders as you are contemplating. I wouldn't use anything else, but others have differing opinions. This is mine.
Oh, I also use 5-30 oil (just for you J), ha ha. Hmm, favorite color? Let me think

Re: Brake fluid
 

If you really want opinions, I'll jump in then. I'm with Kahuna, I would use Dot 5 (you need to understand the difference from Dot 3 & 4) and on the oil 5w30 or 10w30. We could throw in thermostats and water pumps and really have a post!

Re: Brake fluid
 

Re: Brake fluid
 

Just to add to the confusion, the brake fluid industry added (# dot 5.1) brake fluid
to the market.
Don't confuse dot 5 with dot 5.1 as they are completely different from each other.
Dot 5 can Not be mixed with any other brake fluid, but dot 5.1 can be mixed with
dot 3 or dot 4.









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Re: Brake fluid
 

Bleed the system, fill with DOT 3. Dot 5 requires complete flush and/or replace components. Don't put DOT5 in a DOT3 system.

Re: Brake fluid
 

I use Dot 5 also. Since your putting in all new brake cylinders (master and wheel) just flush out the lines with alcohol and your ready to go.

While you replacing the cylinders, check the flex brake lines for softness or spongy feeling. replace as necessary.

As far as oil is concerned, I prefer a heavier grade, 20-50.

Re: Brake fluid
 

I've used DOT 5 in circumstances where I've replace all wheel cylinders, master cylinder and flex hoses. I've flushed the steel lines with denatured alcohol/brake cleaner. They were a little harder to bleed and get a hard pedal-but one car is now on 11 years with DOT 5 and another going on 7 years.
My cars with Dot 3 are the ones that tend to stick up on me after the winter. As they need complete brake jobs with components I'm going to DOT 5 for all. I try to flush the DOT 3 brake systems every couple of years but the wheel cylinders eventually stick and when you take them apart they look like mud and rust inside.