Brake fluid

[Race.it]

Ok, think I know the answer, but just for piece of mind

Today I started to install a new brake system on the 1954, it's a cpp master cylinder under the floor, but unlike the std it's the dual line one.

Now on top of the master cyl it's states use only dot 3 fluid. From what I know I can also use dot 4 or dot 5.1 but should I or do I need to look for dot3

I know in my other hobbie cars I use 5.1 (they get tracked and brakes heat up, but this is not going to get on the track with std drum brakes and not swapping to disks till I do a ifs on the frame.

[1project2many]

All three work. DOT 3 will be cheapest.

[chevyguyase]

Your truck looks like I originally wanted mine to look like. I went with hot rod black though. I also used the CPP brake kit. Like previous answer, Dot 3 is fine.

[dwcsr]

All the fluids are supposed to be backward compatible except DOT 5 which is silicone and can not be mixed with Glycol based fluids. DOT 3, 4 and 5.1 are glycol based. A good practice is to flush the system with what ever your going to use. Its cheap insurance

[Race.it]

Thanks for the replies, was the answer I thought as the whole brake setup will be new, going to put in new hard lines also, I'll prob use dot 4 as easier to get here than dot3

[mr48chev]

Dot 4 has a higher dry boiling point than Dot 3.

The main thing is use fresh brake fluid from a sealed container and it isn't recommended to use fluid out of one of those gallon cans with the pump stuck in it as they draw moisture if the fluid isn't used up in short order. Ok if it's a brake shop that goes through a gallon pretty fast but not good if it's sitting on the shelf in a shop for months on end. That from the Napa EIS brake rep when he put on a brake workshop for my students a few years ago. He didn't like the idea of shops buying 5 gallon pails of brake fluid as he said it sat around too long.

[Race.it]

Same with my other car, think largest I have ever brought was 1 litre and did not use all that, it was to flush a system twice, it's surprising how little fluid brake systems hold

[1project2many]

The main thing is use fresh brake fluid from a sealed container

This warning is on the covers of GM master cylinders. Whenever there's a trainee or new helper in the shop I try to point out that it's impossible to do this. If the container is sealed nothing will come out. If it's open then it's not sealed. Their response usually tells me a lot about how they'll handle conflicting priorities.