Bad vibration after brake job

[dylanborns]

I have a '92 camry with disc front and rear drums. This has been an ongoing problem for the past few months so stay with me while I explain the symptoms. About 5 months ago, I changed the front brakes. The pass. side disc was rusted on so bad, that heat and some work with a rubber mallet wouldn't get it off. It ended up shattering while hitting it with the mallet. The drivers side took some work, but eventually popped off unharmed. The cheap idiot in me decided to take the drivers side disc and have it turned since it was still within parameters, and I bought a new disc for the pass side. New pads, and I'm back on the road.

Fast forward to last month, and I decided that I should check the rears. Same situation; but this time both drums are frozen to the hubs and no amount of mallet and heat would get them off. I ended up cutting around the axle hub with a sawzall, then popping the remaining metal off the hub with a big screwdriver. New hubs and shoes and I'm back on the road.

As I'm driving it a few days later, a few miles into the drive, I notice a light vibration that feels like its coming from the front. The vibration eventually gets really bad and I can feel it in the steering wheel and its even shaking the dash. This happens ONLY when I brake, and not light braking, but when I get the pedal about halfway down to the floor.
So I'm thinking I may have warped the drivers side disc when I applied heat to it. I ended up buying a new disc and replacing the drivers side. So at this point, I have two new discs and lightly used pads. A short time later, the vibration comes back and slowly gets worse again. This is getting long, but I'm almost to the end....

So at that point I take both newer discs back and have them turned. I also get new pads, (free due to warranty), and I'm back on the road. The vibration eventually came back.
Today, I checked the rears, since the problem seemed to start after the rears were changed, and everything looked good. The only thing I noticed that I may not have noticed before, is that it doesn't appear to have "primary" and "secondary" shoes, as they all seem to be the same length. My jeep and ford have a smaller shoe on each side that has to go in a certain place for some reason. The camry shoes seem to be really close in length.

So I got the rear wheels back on and made sure the shoes were adjusted out so that I had the right amount of drag on the wheel. Retorqued all the lugnuts and went for a ride. And the vibrations back...

So the only thing I haven't replaced at least once is the calipers, but I cleaned them when I did the front brake job. It seems like everything is fine until I've done some braking, and either the pads or shoes are heating up. It never starts right away, its always about 10-12 minutes into some braking. I thought maybe the hammering I did to get the discs off had damaged the axles, or the heat had warped them, but I have NO vibration with regular driving; just at moderate braking.
Again, sorry its so long, but I wanted to include all the issues.

Any ideas of what I can do next?

[Brian R.]

Did you clean the surface of the new rotors of preservative grease before you used them? Are the rotors from Toyota or a reputable brand of aftermarket parts?

When you assembled the fronts and drove it, did you treat them like your grandmother would drive them or did you not pay attention to braking force? It is important to brake like your grandmother for at least 500 miles to break everything in together smoothly.

I am not sure what is causing it since I didn't see you do the brake job, but it is most likely caused by your rotors.

[DeltaP]

I gotta disagree on driving it like your grandmother. My grandma would have siezed the calipers by now! But all thats needed to "bed" the pads is to make a 1/2 dozen medium stops from 45 to 0 mph. Ya need to check the entire front end. With all that heat and pounding ya probably damaged something. BTW I rarely turn rotors anymore. Rotors for that car are probably less than $30 each.

[artbuc]

Did you lube the caliper slide pins? From your description, I would guess the slide pins are seized unless you removed, cleaned and re-lubed them.

[Mike Gerber]

Since you say you are feeling the vibration in the steering wheel your problem is probably in the front. I had a similar situation a few years back on my 94 Camry (with 4 wheel discs and ABS). I would start getting pulsation a 1000 or so miles after doing a front brake job with new ceramic pads and new rotors. My problem turned out to be the $30 rotors I got from Pep Boys just couldn't take the heat produced by the combination of full ceramic pads and the cheaper rotors. I exchanged the rotors for their thicker rotors which were about $50 or $55 dollars each, used the same pads and the problem never returned. Are you using ceramic pads with cheap rotors? If so you might have the same problem.

Mike

[DeltaP]

By their composition ceramic pads run cooler but ya gotta have flat,fresh machined rotors to get the advantages out of em. They'll work just fine with the $30 rotors unless they have a defect or your caliper pistons or slides were sticking.

[Mike Gerber]

Originally Posted by DeltaP

By their composition ceramic pads run cooler but ya gotta have flat,fresh machined rotors to get the advantages out of em. They'll work just fine with the $30 rotors unless they have a defect or your caliper pistons or slides were sticking.

I was aware of all that. Rotors were new, slide pins were cleaned and regreased and were working fine. The pads were Raybestos full ceramics. I also lightly sanded the surface of the pads before reinstalling them with the subsequent replacement rotors each time. The problem surfaced twice after a couple of thousand miles after the brake job. The thicker rotors solved the problem. It's been about 3 or 4 years since this incident. My best guess is that the batch of $30 rotors they had in stock weren't heat treated properly. The quality control of some of the stuff you find in chain auto parts stores today is suspect in my mind.

Mike

[DeltaP]

What do you mean by thicker rotors? Did they sell you the wrong rotors with something that fit? How did the overall thickness of the rotors compare? If they were thinner then the pistons could extend too far.
It seems to me that in todays global manufacturing world quality control is the responsibility of the customer. Or, "How much do you want to pay me to make these rotors for you"?

[Mike Gerber]

The "thicker" rotors have more meat in the middle and less space in the area of the fins. The overall thickness of the rotor remains the same. IMHO the thicker rotors are better able to handle the heat generated in braking without warping.

Mike

[dylanborns]

The rotors I bought are around $40 at Oreilly. The pads were the middle priced ones. I did use brake cleaner on both the drums and rotors before I put them on.
I didn't think about the slide pins until my dad mentioned greasing them. I took the wheels off yesterday, with the intent of doing that, but didn't see any "pins" anywhere. I'll dig a little deeper into them tomorrow and see if I can get down to the pins.

[QAC]

When beating on the old disc's to get them off you may have damaged your wheel bearing.
Happened to me on a Mazda 3
Small chance but easy to check
Good Luck

[dylanborns]

The only reason I'm thinking this has to be a rotor or caliper issue is I only have the vibration when applying the brakes. If I had damaged anything on the axle, I would think I would get a vibration at all times, but it only happens when braking.

In the short amount of time I had to take a look at the calipers, I didn't see any pins that I could tell. I saw a rubber boot that could have been covering a pin, but again, I didn't have alot of time to look at them. If I remove the caliper, will they be obvious or are they protected by something and hard to find?

[dylanborns]

Also, to the question of seating the breaks. I've always thought that you were supposed to do what DeltaP mentioned and get it up to a good speed and hit the brakes. Do that a few times to seat them. I usually just do it in my neighborhood which would keep me at 35mph at the most.

[DeltaP]

Originally Posted by dylanborns

Also, to the question of seating the breaks. I've always thought that you were supposed to do what DeltaP mentioned and get it up to a good speed and hit the brakes. Do that a few times to seat them. I usually just do it in my neighborhood which would keep me at 35mph at the most.

Yup, that'll do it too. Maybe you'll have to make 8 stops from 35 mph. I usually chamfer the edges of the linings lightly w/ sandpaper as well. I would recommend checking the wheel bearings. Maybe a broken bearing cage.

[dylanborns]

Wouldn't I feel a vibration at all times if it was the bearings? Not just when I'm braking?