I have a question about brake fluid, since I am rebuilding the master cylinder, the wheel cylinders and replacing most of the brake lines on the vehicle. Other than the fact that the silicone is non-hydroscopic, does it really merit changing the brake fluid from the standard DOT 4 fluid to silicon based (DOT5?) fluid? Are there rubber compatibility concerns with changing to DOT 5? Anyone out there using silicone fluid?

I have also read that when rebuilding the master, only brake fluid should be used to clean the reservoir and the internal parts prior to reassembly?

Has anyone painted their master cylinders (brake)? Since DOT4 fluid eats paint, what is the best paint option? I have some Ceramic 500 degree, Duplicolor silver engine paint that I was planning to try based on recommendation of the local auto parts store.

Thanks!

 

silicone based is more forgiving on paint.

Castrol brake fluid is best but will kill paint.

I wouldn't paint them.

 

If your gonna go silicone go 5.1. If your in a jam, you can use regular 3 or 4 with 5.1, you cannot with 5.


Probably not a concern for you, but 5.1 is also ABS safe.

 

You can use anything to clean the cylinder out, just use brake fluid if you're going to hone it and lastly use soap and water to get all the residue out , then blow it dry with compressed air and immediately lube it down with either brake fluid or the special assembly grease that's compatible with whatever brake fluid you'll be using.

Silicone fluid used to be touted for classic cars that sit a lot because it's not hygroscopic, but just changing the fluid regularly will do as well, and save replacing all the rubber parts. I heard long ago that to change to silicone you had to replace all the rubber components, don't know if that's still true today.

If it were my car, I'd simply use regular fluid and just change it every few years, it's easy and fairly inexpensive to do........

When I did the resto on my XK-E I painted the calipers with engine paint once they were clean and dry, they still look new today. However, I had sandblasted the exteriors so I got a really good bond.......