So the brakes grab pretty good now but...

[THX 138]

... it doesn't have that extra room at the bottom with the added pressure. Maybe the booster is stuck? It looks very old. Does the FOX booster interchange? :help:

 

[HistoricMustang]

Try to put up more information on your problem and someone will jump in with answers!

HistoricMustang
www.historicmustang.com

 

[68GEETEE]

are you saying your brake pedal is hard to push down? you can see if your booster is working by disconnecting and plugging the vacuum hose from the booster, step on the pedal, it should be hard to press. REconnect and try it, it should be easier to push with the booster connected, If not, your booster isnt working.

 

[THX 138]

If I'm at a stop the brake peddle is all the way to the floor. if I barely lift my foot, the car goes forward. There's no extra room. On my other cars I can stop the car and still be able to push down on the peddle a few more inches. It doesn't have that extra travel that most cars have where the last few inches close to the floor.

 

[Route666]

So you need to adjust the pedal height then? Does it start off lower than would be a normal height?

 

[HistoricMustang]

When is the last time you "bled" the brakes and checked the all important fluid level?

HistoricMustang
www.historicmustang.com

 

[THX 138]

When is the last time you "bled" the brakes and checked the all important fluid level?

HistoricMustang
www.historicmustang.com

after the new master cylinder was put on

So you need to adjust the pedal height then? Does it start off lower than would be a normal height?

I dunno what normal is on old mustangs but it seems pretty low. I can lift it up towards me with my hand.

 

[2bav8]

I'm thinking that the brakes need to be bled again too. Your pedel should not go all the way to the floor...

 

[Route666]

I'd try bleeding it again if these guys are reccomending it. Bleed furthest to closest, rear passenger, rear driver, front passenger, front driver.

I'm still thinking you need to adjust the pedal height, but I'm not even sure it's adjustable, and can't really give you any help on how to do it. It should be pretty simple though right? A lock nut and an adjustment of some sort. I'm sure others know how to do it, if it comes to it.

Hang on, you say you can lift it up higher than it stays by itself, isn't the return spring supposed to hold it up against a stop? Have a look at the pedal spring, see if it's attached or corroded badly.

 

[GaPonyFarm]

The pedal isn't adjustable and you should be able to slip your non-braking under the pedal when you have the brakes fully applied. You did bleed the master cylinder before installing it, didn't you?

First try bleeding the brakes again... in the correct order (RR-LR-RF-LF). You might also check the rod length between the m/c and the pedal... your new m/c might require a longer rod. Its easy to buy and install an adjustable pedal rod.

 

[ForceFed70]

Did you bench-bleed the master cylinder before you put it on?

Another vote for air in the system..