Help me narrowdown the non working front brake problem. please :)

[THX 138]

what would make the front brakes not grab at all while the backs do?

back drum, front disk. My buddy and I bled the fronts. Before we bled, not even the backs did anything. Do we bleed them more? What should I do? The disks are pretty rusty. Should I take them off to get turned or can I just get new pads? The car's been sitting for like 6 years since 1998

 

[Jester67]

Start by making sure the master cylinder is full of fluid. Have someone pump the pedal while you check for any leeks, if no leaks move on. If you find a leak fix it before moving on. Next jack up the front, pull the tires and open the bleed screw and have someone pump the pedal if you get fluid bleed them and see if the caliper moves. If not then the caliper is stuck and you will have to rebuild or replace it. Follow the same procedure for the drums in back. Keep an eye on the master cylinder and keep it full. If you do not get fluid then move to the cross over tube loosing the end close to the bleed screw and check for fluid. Work your way back until you get fluid and fix what ever you have to, to get fluid to come out of the bleed screw. The soft line can collapse and that is what was wrong with mine.

 

[302 coupe]

actually, you need to start bleeding with the brake farthest form the master cylinder. So start of with the p.s. rear, then d.s. rear, p.s. front, d.s. front. If your get all the air out of the lines, and your master cylinder is working correctly, the only thing left would be a caliper problem.

 

[Jester67]

My thinking on starting on the Wrong end it to cut down on braking connections that are still good. If you start at the master you will spill more fluid and making a mess he is in the diagnosis stage at this point. As I believe the problem will be found on the caliper end. But I agree that your way will work also.

 

[94CobraPace]

Don't need to turn the rotors, yet. Sounds like the front calipers are stuck. Could pull the calipers and press on the brake pedal to see if the pistons move.

 

[65fastback2+2]

Don't need to turn the rotors, yet. Sounds like the front calipers are stuck. Could pull the calipers and press on the brake pedal to see if the pistons move.

thats what i was thinking would be a good way to check, the only thing is, i find it odd BOTH front calipers would be stuck....kinda odd i would think

 

[Ronstang]

Don't need to turn the rotors, yet. Sounds like the front calipers are stuck. Could pull the calipers and press on the brake pedal to see if the pistons move.

thats what i was thinking would be a good way to check, the only thing is, i find it odd BOTH front calipers would be stuck....kinda odd i would think

I wouldn't suggest stepping on the brake pedal with the calipers off unless you want a huge mess. He has the factory 4 piston caliper Kelsey Hayes disc brakes and it is quite easy for both calipers to be stuck from sitting. They are great brakes but trapped moisture under the dust boots can cause rust in the caliper bore above the seal that effectively locks the brakes up solid. I always bevel this area when rebuilding these types of brakes and put a litte silicone brake grease above the seal area to prevent corrosion.

To free them up you can simply use a C-clamp to push the pistons in to break the grip the corrosion has on the piston. The dust boots can and really should be removed first to try and clean out any rust with Penetrant and compressed air to prevent damaging the seal.

 

[Cavymeister]

After sitting for 6 years, I wouldn't feel comfortable without at least rebuilding the front calipers. Check you hoses. If they are craked, replace them. They're only like $15-20 each. The only other thing I'd look at is the proportioning mechanism. If there is something (rust, trash) blocking the front pipe, then that could also cause the problem. On my 65 it's a Tee block. Take it out and see if there's anything lodged in there.

 

[THX 138]

After sitting for 6 years, I wouldn't feel comfortable without at least rebuilding the front calipers. Check you hoses. If they are craked, replace them. They're only like $15-20 each. The only other thing I'd look at is the proportioning mechanism. If there is something (rust, trash) blocking the front pipe, then that could also cause the problem. On my 65 it's a Tee block. Take it out and see if there's anything lodged in there.

would you rebuild the stock ones or just use them for a core at the auto parts store? I got the stang towed to work (dad and uncles machine shop), and I'm gonna try to get on the brakes tomorrow morning.

 

[Cavymeister]

Personally, I'd just buy the rebuilt ones and use them as a core. I know a lot of people like to do things themselves. I'm kinda lazy like that...

 

[Jester67]

The reason I suggested checking for fluid is to make sure the calipers where in fact stuck not just a clogged or collapsed line. If it is a line that will have to be fixed anyway. I’m not a big fan of just replacing parts until I know what is wrong. Just my .02 cents

 

[jmagilto]

a good starting point.

I would start by 'bench bleeding' the master cylinder:
disconnect brake lines from Master Cylinder.
(attach plastic screwins with little clear hoses back into the resevoir)
pump the pedal until all bubble cease to appear in the clear tubes.

reconnect brake lines.

open one caliper bleeder. depress pedal until fluid appears. close bleeder. release pedal.

repeat all the way around until just fluid emerges.

check for leaks.

edit - if power brakes - bleed w/ engine running.

 

[THX 138]

well surprise surpise my dad threw the rotors on the lathe and fixed everything he said gonna check tomorrow

 

[67wooster]

I seem to have the same problem as THX 138. Can some one offer help.
I have no pedal pressure with engine on and have gone through 2 M/C and one porp. valve. The rear seems to work when the front is cut off but the front shoots the fluid back into the M/C. The car has been graged for 4 years and my mechanic is not able to figure this out.

 

[Skymarshal]

67Wooster-

It sounds like your master cylinder needs to be bled! I just went through the same thing. Brakes wouldn't bleed from any wheel, and pushing the brake pedal just spashed fluid back into the reservoir. You need the plastic fittings that screw into the output ports and have hoses that run back into the reservoir. Pump the pedal until there are no more bubbles. Better yet, do it with the MC out of the car, to make sure you get all the air.

If the car has been parked, you should definitely flush out the old fluid with new, and check everything for corrosion. The brake system is one thing you don't want to screw around with! It's no fun if you can't stop your ride!

 

[gingerbreadman]

Start by making sure the master cylinder is full of fluid. Have someone pump the pedal while you check for any leeks, if no leaks move on. If you find a leak fix it before moving on. Next jack up the front, pull the tires and open the bleed screw and have someone pump the pedal if you get fluid bleed them and see if the caliper moves. If not then the caliper is stuck and you will have to rebuild or replace it. Follow the same procedure for the drums in back. Keep an eye on the master cylinder and keep it full. If you do not get fluid then move to the cross over tube loosing the end close to the bleed screw and check for fluid. Work your way back until you get fluid and fix what ever you have to, to get fluid to come out of the bleed screw. The soft line can collapse and that is what was wrong with mine.

I like this guys idea, start from the bottom (calipers) and move along opening each joint untill you find fluid coming out while you have someone pump, if you make it all the way back to the master cylander then thats your problem....

chances are the calipers are froze up, but it sounds like your dad beat us to the punch...



-gbm-