brake woes

Hello everyone,

I am looking for help because I have been throwing lots of money at some brake problems and I am quickly running out of ammo. I have been doing repairs on a 1996 Mazda 323 constantly since buying it used a few months back. I'm in the Philippines and I am not sure if this car is available in the USA.

The problem started with a leak at the caliper piston seals. There was also a ring of corrosion on the pistons and we spent a while looking for new ones. When we didn't find any at the local parts shops, the mechanic told me it would be ok to simply sand the pistons. I paid the mechanic to use a rebuild kit and the leak was fixed.

After repairing the seals, the brake pedal felt very soft and went down almost to the floor. I was assured that the brakes had been bled and the mechanic told me I needed to repair the master cylinder. Again, I got a repair kit and had the mechanic do the labor. Still, the pedal was soft and went all the way to the floor. Instead of bleeding the brakes again, the mechanic adjusted something at the power brake booster.

After his adjustment, the brakes felt very firm. They were actually too firm. While road testing the car the brakes began to smoke and the car started to get slower and slower. Finally, the mechanic bled the brakes and readjusted the power booster. The problem has not recurred until today but the car has always seemed to have less power since that day.

Today, maybe a month later, the car began to slow and the brakes began to smell like burning again. The pedal was once again very firm. I couldn't press down on it at all. I could apply the brakes, but the pedal didn't move any noticeable amount. I wondered if the pedal was stuck down and I tried to lift it a little with my foot but it didn't come up at all. It was as if the pressure in the brake lines was suddenly much higher than before.

This occurred after braking very hard to avoid a motorcycle rider with a death wish. Since today was a very warm day, I figured that maybe the problem might have something to do with heat. I pulled over to a service station and even though there was no mechanic on duty, there was a man with a hose. He blasted the wheels with water to cool them down and finally I could press the brake pedal down again.

Of course, I went straight to my mechanic and asked him what was going on. He told me that the corroded piston was sticking(but is ok now) and I will need to go to Manila to get some new pistons. It seems entirely possible, but I hesitate to pay for the repair.

Since I am now skeptical of this mechanic and there is a severe language barrier between us, and since Manila is several hours away, and since I will likely have to go back without my own transportation if they give me the wrong replacement part(it has happened several times to me so far), I am seeking some insight before I commit the time and energy to this repair.

Do the symptoms I experienced seem consistent with a sticking piston? My mechanic suggested that I use water again if the piston sticks again. I am confused about why heat would aggravate the corrosion problem. I didn't experience pulling to one side, and wouldn't the pedal come back up if I pulled it with my foot if it were really the caliper piston? I also wonder how he can be certain that the piston was sticking if it actually is ok now and no longer sticking like he said.

Thanks for your advice, Joseph

Reply to
quiet_inthe_corner
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World's Most Boring Car. Popular, cheap, simple. If it isn't, get rid of it.

So find a new mechanic.

There is _nothing_ on a 323 that can't be fixed by a half-trained apprentice over lunch. Certainly not in the brakes. Nor can there be a continent outside Antarctica where you can't get an easy supply of 323 parts.

New mechanic. Or DIY.

Yes. You need to fix that. Pistons (even whole calipers) are cheap, compared to the fuel you're wasting, the brake pads you're wearing out and the disk you're wearing and warping.

PS - There are very few "adjustments" on a brake servo (booster) and the only one there might be doesn't need doing repeatedly.

I've always liked working on brakes. There's just nothing to fiddle with - things are either good or bad, and if they're bad then you're fitting a new part, rather than trying to mess with it. There is almost no scope for "adjusting" or "machining" on brake parts -- if it's wrong, you need a _new_ one.

Reply to
dingbat

Wow. You got some half-assed mechanics there....never throw water at a hot part to begin with, it distorts the hell out of it, and you can't rebuild a badly pitted caliper...if they were that bad, someone was probably driving it on the beach or something. They should have replaced the calipers initially, and any hardware, as I'm sure it is corroded beyond belief and helping the caplipers to stick also...

The 323's also had a very sketchy mechanism for REAR brake adjustment that caused problems on some...if it is the ramp type adjuster. The rears' adjusters are probably seized and non-functional also. Trying to adjust pedal firmness with a booster pushrod adjustment is complete incompetance...I'd suggest you stay away from there.

One thing that puzzles me is rebuilt calipers are cheap and plentiful (at least here)...nobody would ever rebuild one when you can purchase a reman one for less than what the labor would cost to take one apart and fix it...sanding of pistons and bore (if that's what they really did) is insane...they have to be machined with a hone to work well...sometimes if the corrosion is VERY light, a polishing with crocus cloth is all that's required, but the surface has to be very smooth and free of pitting in order to not have binding problems...

It seems they never considered other possibilites either, like a collapsed brake hose that's holding pressure at one wheel and causing drag and overheat...and if you are experiencing enough drag to notice a lack of performance and lower fuel economy, you are wearing out your engine and tranny prematurely, sure as if you were towing a trailer everywhere you go...

Reply to
jeffcoslacker

welll... there are DRUM brakes, which are much more finicky to wear, proper adjustment, etc. There's tons of things that can "wear" that can be compensated for - worn backing plates can be welded up and ground back down, worn drums (so long as they are not worn beyond their wear limit) can be compensated for by arc-grinding the shoes, etc.

But in the context of disc brakes, I agree with you. I'd check the return port in the master cylinder and make sure it's not clogged; failing that, I second the recommendation to recheck the calipers. Another thing to look at would be the hoses; 10 years is a little soon for hose failure, but a hose that is swollen and/or otherwise compromised inside can also cause these symptoms. A set of new hoses would be cheap considering that replacing them would eliminate them as a possible source of the problem. I'm not usually an advocate of throwing parts at a problem, but the labor involved in removing the hoses to inspect them is enough that you might as well replace them and be done with it.

good luck,

nate

Reply to
Nate Nagel

For what it's worth, a good way to check if a drag is being caused by a brake hose....when the problem occurs, crack the bleeder on the affected wheel...a brake hose obstruction that's holding a brake engaged will shoot a pretty strong shot of fluid, and you can often fee/hear the caliper relax as soon as it is opened...other hardware issues don't react to it...

Reply to
jeffcoslacker

Thank you for your advice.

I tried this when the brakes locked up again and it caused them to release. Then the brakes would be ok until I left the car parked for a long period of time. After being parked, the brakes would lock up again after being driven for a while.

Thanks also to Nate Nigel and ding for responding with very good advice. You helped confirm a lot of my suspicions especially about my mechanic.

I did as suggested and got a new mechanic. The new one ended up changing the caliper pistons but felt that the hoses are fine. He explained why bleeding caused the pistons to unstick but it was in tagalog so I didn't understand very much and can't share that explanation.

Thanks again, I really appreciate it.

Reply to
Joseph

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