Crap, my brakes won't release

68converted · Jan 20, 2008

I am getting so close to getting this project on the road. I finally finished the Granada swap and new lines front and back. Did the 4 line bleed, but now the front disc's won't release. They are clamped down tight.

Here is what I have 89 Mustang 2.3L brake booster and MC, Granada brakes up front, original Drums in the rear.

What gives? Any idea why they would not release? All the parts came off of working cars.

ultrastang · Jan 20, 2008

68converted said:
I am getting so close to getting this project on the road. I finally finished the Granada swap and new lines front and back. Did the 4 line bleed, but now the front disc's won't release. They are clamped down tight.

Here is what I have 89 Mustang 2.3L brake booster and MC, Granada brakes up front, original Drums in the rear.

What gives? Any idea why they would not release? All the parts came off of working cars.

If the booster has an adjustable output rod (the one going into the back of the MC), sounds like it may be adjusted too far out and is putting pressure on the brakes even when the pedal is not being pushed down.

68converted · Jan 20, 2008

ultrastang said:
If the booster has an adjustable output rod (the one going into the back of the MC), sounds like it may be adjusted too far out and is putting pressure on the brakes even when the pedal is not being pushed down.

I will check that in the morning, but how much pressure would it take to keep it from releasing? I think if anything, it might have one turn too much. I wanted to make sure that I had quick pedal response, so there was just barely a turn over "just barely touching the MC plate".

ultrastang · Jan 21, 2008

68converted said:
I will check that in the morning, but how much pressure would it take to keep it from releasing? I think if anything, it might have one turn too much. I wanted to make sure that I had quick pedal response, so there was just barely a turn over "just barely touching the MC plate".

Without the brake pedal being applied, the booster's output rod should be close to the MC's piston (within a few thousands of an inch), but should not be touching it.

If it was adjusted too far out, it probably touched and slightly compressed the MC pistons when you tightened the MC to the booster. --MC should be torqued to 25 ft/lbs.

ultrastang · Jan 21, 2008

How to Adjust MC Input Rod Depth

Here's an article, from Maximum Motorsports, on how to calculate the depth to adjust your vehicle's input rod to the MC:

http://www.maximummotorsports.com/content/install/pdf/brakes/MMBAK-2r3.pdf

68converted · Jan 21, 2008

I have the day off, so I am heading over to work on the car this morning. COOOOOOLLLLLD here in Colorado. I will unbolt the MC and see if it releases the brakes.

If that is not the issue, what else could it be? I will take some pics of my setup and post them in a little bit.

68converted · Jan 21, 2008

It is not the brake booster output rod causing pressure on the MC. Any other ideas?

Could gunk/dirt in the MC or portioning valve cause the trouble?

68converted · Jan 21, 2008

Update- Just purchased a new set of calipers, $34 buck for both!!!! (Checker Auto Parts... and the outer Tie Rod ends were only $15 each so I replaced them too). I pulled the old calipers off and used a pump to push the fluid in the lines back into the MC and it worked fine. I dumped the fluid out of the calipers and it came out looking like something died in there.

I just have to coat 'em in Por-15, top coat, and button it back up before I know for sure that I solved the problem, but I am 99.9% sure it's fixed.

Thanks for the tips guys

Crap, my brakes won't release

68converted

Member

ultrastang

68converted

Member

ultrastang

ultrastang

68converted

Member

68converted

Member

68converted

Member

Similar threads

Crap, my brakes won't release

Member

Member

Member

Member

Member

Similar threads

Privacy & Transparency

Privacy & Transparency