Dragging Brakes

[ptstew]

With two different Master Cylinders I have had a problem with the brakes dragging after the car warms up. They are OK the first few miles when cold. Am running FFR cats on a 2002 build. I am thinking that the MC is not fully releasing when hot.
Anyone else has this issue?

[seagull81]

Make sure you have a little clearance on the rod going into the master cylinder and it is straight and not binding on the side.

[ptstew]

The rod is definitely loose, about 1/2 inch of pedal movement b4 engaging MC. Am in the process of replacing cats with j-pipes which I think will run cooler and trying to decide whether to do the MC again while the car is up. It’s a bear to get at the bolts on the inside of firewall with the body installed so not anxious to do it again. Thanks.

[CraigS]

My MCs are directly over top of the headers (CNC 241)
https://www.cncbrakes.com/Product.aspx?grp=dcbpa&subgrp=ba&series=240&subseries=
and I have never had a problem like yours.

[davekp]

Is it all wheels dragging, or two, or one?

[ptstew]

Both fronts evenly. Backs seem ok, but not sure about that.
Thanks.

[davekp]

I had a similar problem on a Corvette- turned out to be a too tight MC actuator rod. Try a bit more slack in the front.

[Paul2STL]

With two different Master Cylinders I have had a problem with the brakes dragging after the car warms up. They are OK the first few miles when cold. Am running FFR cats on a 2002 build. I am thinking that the MC is not fully releasing when hot.
Anyone else has this issue?

What type of brake system are you running? I had my brakes dragging also, but fixed with a spacer between the master cylinder and booster. When i first put it togethor I used one spacer from FFR kit then added another one and haven't had the problem since. Then added on after having the same problem you experienced. I am running Mustang brakes front and back with a 93 mustang booster that I got from Whitby.

[ptstew]

Brakes are stock 91 Mustang w/o power boost and I used the one spacer that came in FFR kit between firewall and MC. I am convinced by these posts to add a couple of washers to give the rod more room. How difficult would it be to install the Whithby power brakes to a completed Mark I car?

[JRD56]

Make sure you front calipers are not the problem. Take the tires off and smack the calipers with a rubber mallet. If the rotors turn easier after doing that its the pistons in the calipers binding and causing the issue. Ask me how I know.............

[ptstew]

Thanks. I tried that and neither one got looser. I also checked mc rod free play and eyeball ~3/16”.