Brake problem on Fox Mustang...

Car has stock brakes all around. Stock MC with no power booster. The pedal has been modified for use with manual brakes. Problem is it had a soft pedal. Car seemed like it had a bad MC.

It's got new pads, shoes, calipers and cylinders all the way around. The new MC made it better, but not a hard pedal like I would expect. Any ideas?

Does it need a smaller bore MC because of the conversion to manual? Or is the stock MC fine since it still has stock discs/drums on it?

I bled the brakes real good too. Still no luck...

Which master are you using?

Car is for a friend of mine. It's BBF powered...

Stock power MC. Booster has been ditched. I modified the power pedal to be just like my stock manual pedal. This involved lowering the pedal in the pedal mount, shortening it and raising the pushrod hookup location.

Car next door has an "aftermarket" Mopar style with 4 wheel discs (Aerospace and Strange) and has a rock hard pedal and stops excellent from 120+...

Anybody know the bore size of this MC?

you will need a larger bore diameter for the harder feel. Did you buy a stock MC for a booster application or did you get the the old one for the mustangs with manual brakes?

This a stock power brake MC. Is the thread size different on the manual brake MC? Just curious if I'll need to change lines or not. Car is an 89 model. I suspect the fittings are metric. It has the aluminum MC. I had saw somewhere where a late model Ranger had manual brakes and an aluminum MC... Any ideas? curious if it would be a direct swap and not have to swap from the 3 port style to a 2 port style, change fittings because of SAE vs metric, etc...

Pedal ratio is 6:1 just like Wilwood recommends...

I'd try a different MC. I put a kit on mine that come with an aluminum MC..... Can't remember the MFG?????

This one is a "new" rebuilt unit from Autozone. Maybe it's bad too...

Not my car. I'll have him get another one...

Making sure the rear brakes are as tight as possible without alot drag will help from my experiance.

Already checked that. They are tight. Brakes are crap. Won't even hold the car to powerbrake it... I'm at wits end here.

I would gut the propurtioning {SP} , it may be stuck and if its not it should give you 50/50 front to rear brakes which is good when you have slicks on back, Goodluck.., ED

What will it being stuck do?

I thought it just limits flow to the rear? I've gotten clean fluid from each bleeder screw when I bleed it. Doesn't seem like any one is flowing slow or low.

Pistons to small, Need one that will allow more force.

The Leverage on the rod will affect the pedal feel and how it works a whole bunch too.

The pedal is a copy of a factory Ford manual brake pedal. So the leverage should be correct. Wish I could find out the bore size on a manual MC vs a power one.

I can't bolt in a Ford cast iron manual MC due to the fittings being metric on the car and SAE on the manual MC. I'm looking for some adapters though.

I'm also going to bleed it one more time but with one fo those power bleeders. I didn't drive it but the owner did and he said it's not much better. I'll have to ask him if the MC has a warranty. IF so, it's going back to get replaced. I might also steal one off of a known good car to try. Just to rule out the MC ...

did you bench bleed it?

like a sumbitch...

jbozzelle wrote:This one is a "new" rebuilt unit from Autozone. Maybe it's bad too...

Not my car. I'll have him get another one...

I would go get another master cylinder from somewhere other than the Zone I had a truck several years ago went through three master cylinders in 1 week from there, went elswhere and bought one and never had another problem I wont buy anything from them.