1994 Corolla brakes lock

[ExpressVan]

I have a '94 Corolla with 1.6L engine that recently started pulling to the right and locking the brakes when the brake pedal is pressed firmly. The car does not have ABS. When I examined the front brakes, the passenger-side pads are worn down to about 25% of useful thickness, while the driver's side pads look virtually brand new.

I took the car to a local garage, where they wanted to replace virtually the entire brake system for over $700 (apparently in hope of finding the problem without actually understanding it ). My shop manual suggests the most likely causes are a failed proportioning valve (which was my first guess when I saw the pads) or a bad power boost unit.

Has anyone had a similar problem? If so, what did you do to fix it?

Thanks!

[MonteSSman]

I was looking at your forum, and noticed you had a similar problem I am having with a 96 Corolla. Mine however is the drivers side front. I too had it to the local shop and he blead the system several times and then suggested a new master cylinder. I noticed your post was a while ago, but I was wondering if you ever got anywhere with your system?

[SpinnerCee]

Start with the simple stuff...

Those same symptoms will also occur if you have mis-matched tires on the same axle (ie not the exact same circumference) , or tires on the same axle with different air pressures.

You didn't say anything about rotor history, but if the rotor thickness is different left to right you may also see the same issue.

A frozen or stuck caliper on the side that's not wearing the pads out could also be something to look at. While not the best idea, swapping the well-worn pads to the other side and vice versa, may reveal the caliper issue, or correct it altogether. Sometimes shops will press the caliper piston too deep actually lodging it in the bore -- the thinner pads may free the piston in the bore and restore equal braking.

[MonteSSman]

Here is the quick history on my 96 Corolla. We have had the car since it was new. The car has 180,xxx miles on it. All the tires are the same size Michelins, and all at the same pressure. The front brakes are still good and thick. The rotors are not warped and are still thick enough to be turned again. The rear brakes are new with in the last 4 k miles. The guy that did my work, has always done my work and has done brakes for 18+ years. He blead the system 4-5 times thinking there was air in the line. He suggested a new master cylinder (around $180 new) because the petal just does not feel normal, but it is not spungy. I think it just does not feel that it has the stopping power it use to when it was new either. When you get on the brakes HARD, #1 the car pulls to the left and if you really get on it hard, ONLY the drivers front wheel will lock. The caliper is not sticking/stuck, but it is like that wheel has more pressure on that caliper than the others. That is why I am leaning towards the master cylinder. However, I guess it could be the power booster...? When talking to a true friend at the Toyota shop, he said they almost never have master cylinder go bad, so they don't even stock them.

[dosser]

Have the calibers ever been replaced? Even with bleeding worn caliber bores can hang up and cause this problem. Also if the rubber seals on the caliber are old, moisture can get into the bore and rust and you won't even know it, and this can cause sticking or binding of the pistion. I replace the calibers every third set of disc. pads.

[rockwood84]

dosser is right if the calipers have not had any thing done but sqeezed back then sqeezed back each time new pads were put on then its time to put some new ones on or rebild the ones on it the seals are probably hanging the caliper up i have a '92 with 318,000 miles on it and i finaly broke down and did mine because one side or the other was wearing out before the otherside. and i had lifetime warranty on pads but got tired of putting pads on . take the calipers apart and see what they look like on the inside then decide wheather to rebuild or bite the bullit and put a rebuilt set on or new ones on.but thats your problem caliper bore or seals. if the bores look and feel smooth the seals are not much $$$$ good luck

[MonteSSman]

Just an update. Well, here was my answer. The slider bolt on the passenger side was not sliding on the top side of the caliper. Therefore, only the bottom half of the pad was being applied to the rotor. Thus created the pull because the left side had more stopping power. Removed the stud, cleaned the rust off, greased it, put new rotors and ceramic pads on the front. Then replaced all the brake fluid. The car will almost stop now just by looking at the brake petal!!! It is awesome.