MadCityRich

I've got a brake shake problem that has me a little stumped. It's a 2002 4Runner and I installed rebuilt Tundra 199mm brakes/rotors/pads a couple of years ago. Here's the symptom:

After driving and braking for a while, I get a progressively worse shaking in the brakes. The feeling is mostly in the steering wheel (very strong and rapid shake) and in the body of the 4Runner (like in my seat). The pedal feel is fairly minor.

I put the 4Runner up on jack stands to investigate things. The passenger side front wheel rotated fairly easily, though a little tighter than expected. The drivers side front wheel was very tight and took some effort to rotate with the wheel still on the vehicle. This was observed after the 4Runner had been sitting overnight.

I took off the wheels and noticed that the inner pad of the driver's side was a bit more worn than all the other pads. The passenger side pads have uniform wear.

I was thinking that the caliper retaining pin might be somehow preventing the pad from releasing pressure, so I lubed them with caliper grease. When I installed the driver's side wheel and tightened the lugs hand tight with a wrench, the brakes seemed to bind. Looser lugs allowed for much easier rotation. I then took the wheel off, did a little percussive maintenance to loosen the pads, retightened the wheel, and things seems to rotate just fine.

Took the 4Runner for a drive with lots of braking. Very smooth to start but the shaking returned as the brakes heated up. Just as it had been doing.

I'm a bit stuck on where to look next. Could be the calipers aren't releasing pressure properly, but I suppose it's possible I also have a warped rotor that could have a high spot. My guess is that if the rotor is warped, it might have a high spot that is hitting the inner driver's side pad and that when the wheel is reinstalled, that high spot is hitting the pad as the rotor is pressed into place.

Any thoughts on a diagnostic process would be great. I'm a believer in starting with the simple stuff before increasing complexity and expense. Should I have the rotors turned to see what happens? Time to rebuild the calipers (I doubt it)?

Thanks much,

MadCityRich

Yukon

I would think that since the inner pad has been rubbing, it developed the high spot, and the reason that it is worse after driving, is it is still rubbing, and warming the spot up.. then when you brake you can just feel it more. I would try to replace/rebuild the caliper..

george

also check your brake hose. If the inner walls collapsed it can cause the caliper piston not to retract and release the piston and pad - ask me how i know this.

pump your brakes with the wheels up and both sides should release evenly.

954rrmike

I also have a bad shaking issue with the tundra setup that I installed two years ago. My conclusion is that all the rotors you can buy come from China and they are poor quality. I am going back to the 16" 4runner setup with EBC pads and Brembo rotors very soon as the shaking is driving me nuts.

raydouble

I would guess a "stuck/frozen" caliper piston......try pushing the pistons back in with a c clamp and see if anything changes.

MadCityRich

I did a bit of investigating and determined that indeed, the driver's inner caliper piston/s were stuck. Using a pair of pliers I could get all the other pads to retract except that one.

When I removed the rotor, I could see just how bad it was. The rotor was badly scored with a pronounced groove taken out of it. The shop said there was too much material lost for turning it. I'm still amazed that I never felt the truck pull in any way when just driving or applying the brakes (other than the judder).

With a newly rebuilt caliper, rotor and pads, I'm driving and braking as smooth as silk. In two post-install tests I've confirmed that the brakes aren't binding at all.

MadCityRich
'02 4Runner