Mustang brake issue

slickstang

Club Member
OK so what i got is front brakes from a 2001 mustang and stock rear drums
master cyl is stock.

the problem is the front brakes are binding and it does not appear that it is the calipers they appear to be free.

is it because i am using the stock 91 m/c and proportioning valve?

any help would be appreciated.


Thanks
Carl

Oh and btw for those that dont know the car is a 91 mustang notch
 
OK so what i got is front brakes from a 2001 mustang and stock rear drums
master cyl is stock.

the problem is the front brakes are binding and it does not appear that it is the calipers they appear to be free.

is it because i am using the stock 91 m/c and proportioning valve?

any help would be appreciated.


Thanks
Carl

Oh and btw for those that dont know the car is a 91 mustang notch

Does your car have 2 or 4 wheel ABS??

Possible the 01 MC has too much front bias (not sure on the differences in splits from year to year).

Aren't there two ports on the 01 MC?? If so why are you using a proportioning valve?? One line goes to the rear brakes and one goes to the fronts. 01 MC should have internal bias.

--Joe
 
Does your car have 2 or 4 wheel ABS??

Possible the 01 MC has too much front bias (not sure on the differences in splits from year to year).

Aren't there two ports on the 01 MC?? If so why are you using a proportioning valve?? One line goes to the rear brakes and one goes to the fronts. 01 MC should have internal bias.

--Joe

No ABS the car is a 91 and I am using the 91MC and valve
 
what model '01? cobra/ v6/gt? caliper size/ count will matter. the v6/GT have a 44.5" bore dual piston caliper. MUCH larger than the stock fox brakes. you need a larger master cylinder and im guessing the best solution would be to gut the stock prop valve and use an adjustable unit since the rear brakes are stock.

at the very least id say: "93 Cobra 1.00" master cylinder (or a 94-95 15/16" bore cobra unit for a softer pedal feel). Can use 94-98 V6 1 1/16" for use with the larger GT/V6 PBR calipers"
 
Last edited:
I just reread what you said.......I fucked up, thought you said you were using a 01 mc.

:blush:

--Joe
 
Yes. the Fox cars had a crossfeed system for braking the later cars had direct feed and no proportioning valve.

Put stock MC back on it. It should work OK but a adjustable Prop Valve would be a good idea.

OK so what i got is front brakes from a 2001 mustang and stock rear drums
master cyl is stock.

the problem is the front brakes are binding and it does not appear that it is the calipers they appear to be free.

is it because i am using the stock 91 m/c and proportioning valve?

any help would be appreciated.


Thanks
Carl

Oh and btw for those that dont know the car is a 91 mustang notch
 
Yes. the Fox cars had a crossfeed system for braking the later cars had direct feed and no proportioning valve.

Put stock MC back on it. It should work OK but a adjustable Prop Valve would be a good idea.

it will likely have a very soft pedal with the stock fox MC. I got a soft pedal when i swapped to cobra calipers up front (which are smaller pistons) so a bigger piston caliper would only make it worse. since you have it though id give it a try, everyone likes a different pedal feel.
 
what model '01? cobra/ v6/gt? caliper size/ count will matter. the v6/GT have a 44.5" bore dual piston caliper. MUCH larger than the stock fox brakes. you need a larger master cylinder and im guessing the best solution would be to gut the stock prop valve and use an adjustable unit since the rear brakes are stock.

at the very least id say: "93 Cobra 1.00" master cylinder (or a 94-95 15/16" bore cobra unit for a softer pedal feel). Can use 94-98 V6 1 1/16" for use with the larger GT/V6 PBR calipers"
the calipers say pbr on them and they are Large.

Yes. the Fox cars had a crossfeed system for braking the later cars had direct feed and no proportioning valve.

Put stock MC back on it. It should work OK but a adjustable Prop Valve would be a good idea.
So a stock 94-98 MC and a adjustable PV.
will that bolt up to the orriginal 91 4cy brake booster or should i just eliminate that?
 
Id use the 94-98 specific booster as its a bit larger to help with pedal effort and use an adjustable valve.

the v6/gt PBR calipers are the 44.5mm bore units.
 
If you swap the lines and use a prop valve setup for rear drums you should be ok. Why not swap out to the 94-98 rear brakes ? I think the non abs cars had the same axle offset as the fox IIRC but you may want to check on that.


the calipers say pbr on them and they are Large.


So a stock 94-98 MC and a adjustable PV.
will that bolt up to the orriginal 91 4cy brake booster or should i just eliminate that?
 
Now I am putting rear cobra disc brakes on the rear
I have the ranger axles and the rear disc's are to deep they hit the backing plate. does anybody know off hand what rotors I may need for this application.
 
Now I am putting rear cobra disc brakes on the rear
I have the ranger axles and the rear disc's are to deep they hit the backing plate. does anybody know off hand what rotors I may need for this application.

See if discs from a Explorer/Mountaineer will work.
 
what brackets are you using? stock or the NRC? and how are you setting up the brackets?

I had to do this to my stock brackets to get the stock rotors and calipers to fit:


I cut a notch out of the brackets (not in half like pictured but the black lines). been running is and racing it like this for 6 years without issue, i still have the pieces I cut out in case I wanted to weld them back in
Bracket%20cut.GIF


and then mounted them behind the axle housing flange, notice the washer between the caliper and the bracket:

LTD%20Brake%20conversion%20003.jpg
 
Last edited:
I am using the stock brackets and the rotors are off by about 3/4" the offset of the rotor is to deep.
the rotors are 10.5"
 
Last edited:
Back
Top