I've been trying to track down a problem with the brakes with this car since I bought it last fall. Originally it just had warped front rotors after I bought it so I put new rotors and pads on the front and problem solved.

After that I started to notice two problems. Once the brakes got hot, say after driving for a half hour or so, the car would pull to the right under hard braking. I narrowed this to the rear brakes since I got the same result when I pulled the e-brake lever. So I replaced the rear drums and shoes. No change. My next step with this is new wheel cylinders since they are pretty cheap. The other problem that I noticed was that the front brakes don't seem to be releasing completely. My brakes do squeak a little sometimes when coming to a stop. Sometimes I can here the same squealing after I pull out from a stop then it goes away. It seems like the releasing of the calipers is a little delayed, or they're not releasing completely ever. This also seems to only surface after some driving time.

A couple days ago my brake light came on, so I checked the fluid and it was low. I added some and figured I probably forgot to top off after the last brake job, since I removed some to make room for the new shoes. I was changing oil today, and noticed it was somewhat lower again. That's when I noticed fluid on the front of the brake booster under the master cylinder, and on top of my transmission. It looks as though the master cylinder is leaking. My questions are:

1. Could this leak be causing my pulling if air got into the lines through the leak?

2. Could this also be causing the brakes not to release completely?

3. Should I replace just the master cylinder, or could there be damage to the brake booster as well from the leaking fluid?

 

Sounds like a caliper is dragging, not retracting properly. I assume you replaced the pads on the front. Why did you remove fluid from the master? If the pads are really worn and the pistons are way out pushing them back in not pefectly staight could score the wall and cause the piston to bind, causing pull and excessive heat. If air got into one side it could be possible that the other side would "pull". I don't think the leak will damage the booster. Clean it well once apart and look it over.

 

If the resevoir is full when you do a brake job, you will overflow the resevoir when you put new pads/shoes on since they will the pistons/wheel cylinders will need to be pushed back in since they are thicker than the worn set. Of course, if you let your fluid get low over the life of the brakes, you wouldn't need to bother, but I keep my fluids at proper levels.

 

I have never taken the cap off nor removed brake fluid when replacing brakes on a neon and haven't had it overflow, just an FYI.

 

well rule out booster fluid doesnt run through the booster sounds like ampb5 is right sounds like a dragging caliper or dragging read drum did you adjust your rear brakes? one could be grabbing harder than the other or you could be looking at brake fade on only one side of the vehicle which is rare

 

This is probably not your issue, but double check the rear brakes to see if they are engaging and/or adjusting properly.

When I got my car running, I found out that the rear brakes was not functioning as it should and when I pulled it apart to find out if I needed new shoes, I found that the previous person who worked on the brakes put one of the springs in the wrong hole, so the adjuster was just flopping around and doing nothing and it allowed the brakes to basically not engage. The locations of those springs is absolutely critical - especially for the automatic adjuster to work right.

If your rear brakes are not handliing some of the load, the front ones are doing double duty and could be part of your problem.

 

Yeah, I looked all of this over when I did the shoes last time, everything seems to be in place and working. I originally didn't think that air in the lines could be causing the problem in the rear, since I saw the problem with the e-brake as well, but the more I think about it, it may be possible. Since the adjusters work when you engage the brakes, if the brake isn't engaging properly, or with not enough force, the adjuster may not be able to function. It just a theory, but I guess it's possible.

I'm replacing the master cylinder over the week-end, and am most likely going to do wheel cylinders at the same time, since they're cheap and I'd have to bleed the system anyway. I'm also going to remove the front caliper/pads, lube the pistons and reinstall those and see how that works out as well.

 

I don't know that I would lube any part of the brake caliper cylinders as ANY lube you use (silcon based or oil based) can end up in on the brake pad and create a world of S#$% that you really don't want to be a part of....In fact, I believe that it is highly recommended that you do not lube anything.

If you have any issues with burrs or edges or rough spots on the caliper use an extemely fine steel wool to polish it out.

 

Never had any trouble with that. Of course if you're messy and get it all over the rotor or pad you'll have problems, but if you keep it on the slide pins and pistons where it belongs you shouldn't have any issues. Nonetheless I bought new calipers. The parts have been sitting in the garage. I would've done all the work yesterday, but the fact that my power has been out since Friday night, until about 2 hours ago, I haven't been able to work on the car.

 

FWIW, step 2 in my repair manual after taking the wheels off tells you to remove two thirds of the fluid in the resevoir. Just noticed it tonight while glancing through while replacing the master cylinder.