Car shakes violently while braking

[dath]

Hello All,

I'm new to this forum and thought it looked like the kind of place where someone may have an answer to my question I have a 1998 Camry V6 with about 160K miles on it. A couple of years ago I had to replace the front rotors as they were warped. I replaced them with cross drilled power stop rotors and the problem was cured.

A few months ago the car started to show similar symptoms to the first time around. The brake pedal seems to pulse and the car shakes violently sometimes when braking from freeway speeds to a stop (like getting off on an exit ramp and braking firmly). The steering wheel shakes very badly as well. I pulled all four wheels and checked for runout and the largest reading I got from any wheel was .0025", which seems fine to me and certainly wouldn't be anywere enough to cause the kind of shaking the car has. I pulled the ABS fuse and it didn't make any difference (though I'm not braking nearly hard enough to activate the ABS). I also replaced the strut tower mounts as I had the dreaded clunking. I previously replaced the struts as well with KYB-GR2 struts and they still seemed fine when I pulled them off again.

Also, at slow speed the brakes will tend to grab and let go, slowly rocking the car to a stop.

Any ideas? Could this be as simple as an alignment problem? Brake proportioning valve maybe? I really don't want to spend too much money replacing random parts at this point, it's my wife's daily driver, what I would call my "other" car

Thanks in advance!
-dath

[cam2Xrunner]

Probably the front rotors again. What kind of pads are you using?

[RningOnFumes]

i had smilar problems with my rotors a few years back...take off one of the front wheels..or both...check your brakes..any pitting or warping on the rotors?

[dath]

No, that is what I was trying to say in my post, I pulled all four wheels and checked all four rotors for runout. .0025" was the largest reading. That is not much runout at all and wouldn't cause this problem. That's part of the reason I'm a bit stumped. . .

EDIT:
I don't recall what kind of pads I put on, but I *THINK* I used OEM pads from Toyota as that is normally what I would do. . . I only changed to non-OEM rotors as the originals warped without any abuse, so I wanted to change to something I thought may work better.

-dath

[dath]

Anyone? I'm hoping to fix it this weekend if possible as I have a very busy work schedule and not much time to tool cars these days

[karugs]

Another possibility is worn ball joints when feeling a pulse during braking. Front suspension in top condition?

Or maybe you're stepping too hard--ABS is kicking?

[majorgercko1]

make sure ur nuts are tight.

[604-Mico]

that happened to me and the strangest thing was behind the problem

a blown fuse for the brake lights
if you press on the brakes and the reverse light come on your dash, thats the prob

my car shoke is crazy when slowing down and that solved the prob

[dath]

Originally Posted by karugs

Another possibility is worn ball joints when feeling a pulse during braking. Front suspension in top condition?

Or maybe you're stepping too hard--ABS is kicking?

Hmmm, I didn't check the ball joints. I'll check those and reply back, that's a good thought. And no, I'm not stepping on the brake hard enough to kick in the ABS, it doesn't really take much pressure to get it to happen. I have to go on a long drive today, so I may not get to checking them until tonight.

604-Mico - I don't think the reverse light is coming on when I step on the brakes. I'll double check just to make sure. That sounds like a very strange cause of this kind of issue though?
EDIT: Oh yeah, also, I know the brake light fuse is good, I just replaced a whole bunch of lights on the car that were out and the brake lights were working afterward.

majorgercko1 - I'll check my nuts. I didn't see anything obvious when I looked at it last time, but I'll double check all the nuts/bolts in the front suspension just ot make sure.

Thanks for all the replies!
-dath