I just recently purchased a '68 Mustang and am having some problems with the brakes. It has disc on the front and drum on the back. Soon after I got it, I noticed that the front brake lines were dry rotting and leaking so I replaced those. I tried bleeding the brakes several times with some of the so called single man methods with no luck, so I decided to take it to a shop to have it done. They powerbled the brakes, but my pedal still feels really mushy. I can press it all the way to the floor without locking the brakes. My brake light stays on and they tell me that it's the proportioning valve that needs replacing (they say it won't center). Could that be part of the problem? I also know that the front left rotor needs replacing (inside is all grooved out) and I have a set of those on order along with a set of brake pads. I'm wondering if replacing those will help the problem. I would probably do the same with the rear shoes. Not sure what condition the drums are in. Any help would be appreciated.

Vern

 

They didn't bleed your brakes properly. The light is because the prop valve is off center, like they said. However, it will recenter itself, no need to replace it. You just need to find out which side it has slipped to (front or rear).

 

I hate to sound dumb, but I'm only a fair mechanic. I mostly figure it out as I go. How do you go about figuring out which side it went to?

 

Never went through this, but open both rear bleeders and step on the brake (capture the fluid of course). Then repeat for the front. Should be reset. I don't have my old car book here that details the procedure...but, that's what I remember from reading it at one time.

Someone here may correct me, however.

 

Did they check out the rears? No leaks there? Any meat left on the shoes?
Also, if the rears are way out of adjustment and therefore not contributing, that can also lead to spongy pedal feel.
good luck

 

I didn't really have them check out anything. I just wanted them to bleed the system (hard to do with only one person). Before I replaced the brake lines, the brakes felt pretty good. At least as good as I figured they should feel for a car this old...trustworthy enough for interstate driving. Now they're bad enough that I wouldn't dare drive that fast.

As for adjusting the rear brakes, don't they do that automatically when backing up with the automatic adjusters? What you're saying makes sense and I suppose all the attempts I made by myself could have messed up the adjustment.

 

Based on my experience yesterday, I would rebuild all for corners of your brakes. Then see how she stops.

 

here's what you do, wait till it rains good, go to the local shopping mall (after closing time) find the biggest section of parking lot, bring it up to speed and slam on the brakes, if they lock up you're GTG, if not well that's a different thread all together (j/k). Get a second person and try a few of the two man methods...

 

Check to see if your rear cylinders are leaking, make sure the shoes are good and check to see if the drum itself is within specs. If everything there is Kosher, go to the front. Pads and discs good? (You already answered that one). If everything there is good, you are good to go.

Now, bleed the brakes in order from farthest to closest, use a second person for this. Start at the opposite rear corner that your MC is on (double check, but it should be RR, LR, RF, LF). This should re-center your prop valve. If your brakes are still squishy you may need to replace your prop valve or MC.

Good Luck to you.

 

Sounds illegal...but fun! [sm=badbadbad.gif]