Brake problem - Urgent

Since two days ago my '94 LeSabre has yet another problem, this time with the brakes. Sometimes I press the pedal and it works just fine, but sometimes the pedal goes down much farther than it should. Eventually the brakes are activated and they work just fine. This doesn't happen every time, but it's happening more and more. When it happens, if I let go off the pedal and then press it again, it works as it should. I know the brake pads have been changed a few months ago, and until now the brakes didn't give me any problem, so I don't think the mechanic screwed up anything.

I have the Chilton manual and I tried to figure out what's wrong, but I don't know much about mechanics and the brakes section seems really complicated to me, definitely not something I would be able to do myself. However, I thought maybe someone here could give me an idea of what's wrong based on the symptom.

Thanks,

Sebastian

You have a leaking piston seal in the master cylinder. You need a "new" master cylinder. Many people have problems after a few months, with rebuilt units, that is why I recommend a "new" master cylinder. Better let a shop do this, since you have limited mechanical experience.

You have a leaking piston seal in the master cylinder. You need a "new" master cylinder. Many people have problems after a few months, with rebuilt units, that is why I recommend a "new" master cylinder. Better let a shop do this, since you have limited mechanical experience.

Thanks for your reply. Is it dangerous to keep driving it this way for a few more days? Even when I have to press the pedal more, it still brakes fine, it's just that it seems harder, but not impossible.

Also, a search for the master cylinder in partsamerica and the autozone shows that there could be two sizes for my vehicle, 6.5" and 8". How can I know for sure which one mine is?

Thanks

It should be OK to drive a few days like it is. You will need to measure the length of the master cylinder to know which on you need, or you could take it to Advanced and let them check it for you.

I agree with the leaky piston problem.. Unfortunately it seems to be a little dirt in the system too.. thus the intermittent problem.

You have a leaking piston seal in the master cylinder. You need a "new" master cylinder. Many people have problems after a few months, with rebuilt units, that is why I recommend a "new" master cylinder. Better let a shop do this, since you have limited mechanical experience.

Pardon my ignorance, but I don't suppose there's a way to replace just that leaky piston seal, is there?

I think I might try to do the whole thing myself. I read the procedure in the Chilton manual and it looks like something that might take a while, which tells me I would have to pay the mechanic a lot of labor, and not only I don't have much money, but also by now I hate this car so much that I don't want to spend one more dime in it than absolutely necessary. I mean, this thing has been a nightmare since the beginning, a new thing breaks every month, and I already put like a thousand dollars in repairs, and it will probably need $500 more at least to repair the current set of problems, plus around $1200 to repair the A/C. (which I can't do myself because I would need to be EPA certified, as I learned). So even if it takes me a whole day, I'm willing to learn to do it myself. The bleeding seems like the most difficult part, but I can buy a bleeding kit for less than one hour of labor of most mechanics, so I'm willing to give it a try.

Do you have any opinion on a Tru Torque new master cylinder? The AC Delco is around $200, and this one is $66, which tells me it's not the same quality, but I don't want to shell out the big bucks on this car, so if it does the job, that's what I'll use. Unless you or somebody here knows it to be extremely bad and dangerous, so I'd appreciate some feedback. The next two choices are Bendix ($143) and Raybestos ($156).

Thanks for any feedback on this.

Sebastian

I'll agree with Hot Z,brakes are not to be delt with unless you know exactly what your doing,you or someone elses life may depend on it.Take it to a pro and have it done,also I believe the days of replacing cups in wheel and master cylinders is done.