Front brake master/caliper swap ?

[papanovember]

Hello to all,
I am replacing the front master cylinder(with the parts-n-more one) and I have a spare set of calipers, that I have rebuilt, to throw on my 79F. My question is, should I try to drain the system first? Or just keep as much brake fluid in the system, to keep the air out? I know it's gonna be messy either way...

[DiverRay]

I would change the fluid. You should do it every other year, at the most. I put a P&M master on daily ride, added stainless lines, and rebuilt the calipers. I then went to DOT 5 brake fluid. Have NOT had any problems.
If you do go to DOT 5, you MUST get ALL the old fluid out of the system. I figured as everything was dry, that was a good time.
Ray

[HobbyMan]

I would flush the system pretty well. I advise against DOT 5. It isn't nearly the same stuff. Dot 5 does not absorb water so It will collect at the bottom of the calipers. Dot 3 will take in the water so that when you change your fluid, the moisture will be removed

[mro]

to dot or not (5)

originally posted by HobbyMan
I advise against DOT 5. It isn't nearly the same stuff.

Both good and not so good about 5.
In a new system I would use it, little better proprties than 3/4.

Putting into old brake lines may not be such a good idea tho.
Have heard you can "flush" out all the 3/4, but would not like the mess 5 will make if you don't get all the old stuff out


mro
btw. SS lines rule
I'm NOT going to try a stoppie on my hot rod XS, (use reg brake fluid with ss lines, drilled rotors etc..) think it could do it

[papanovember]

I am not going to replace the brake lines. I put SS lines on about three years ago. So, I will stick with DOT 3. I was just wondering if anybody had done this without changing the lines. I will probably suck as much as I can out of the master cylinder, hook up the new one, then change the calipers out. Thanks.