Brakes issues 2001 4runner

[sacsr]

Plan on taking it to the dealership unless some one has an idea what I should try next. Replaced my rotors and pads....had a drivers side caliper piston that was sticking and in the process of trying to get it unstuck I knocked it out. A good bit of oil had dripped out before I was able to get it stopped. Put new caliper on......took it too a mechanic buddy of mine.....put it on the racks and bled all the lines....took it out and it was "jumpy" pulsating terribly.....put it back on the racks...adjusted the rear brakes.....bled the lines again......still pulsating terribly......(when bleeding the rears we realized we had to turn the car on for the rear bleeding to work).......finally bled the mc to see if that was the issue....still pulsating brakes......

Where have we gone wrong???

Thanks I have searched a good bit of the threads....and did not find anything that I felt was the solution.......

Any help will be greatly appreciated!!

 

[LittleCaesar]

Do the rotors spin freely without touching the pad if you rotate them manually?

It seems as if you may have a couple of hot spots on the rotor, even if they are almost new. What ones did you use?

 

[sacsr]

I used autozone rotors and their cmax ceramic pads. There is a little stickiness too them when you rotate them......but before I replaced the caliper I had the same pads and same rotors on and they were braking fine not pulsating.....but I had a scraping noise so I took off the drivers side because it sounded like the noise was coming from there.......felt the stickiness of the pads and rotors so pulled the pads out and that is when I had an issue with the piston getting stuck in the caliper and damaged it trying to get it back in....the noise ended up being the other size and the metal shield being bent. (after all this is said and done).

This may be an issue....when I took the pads out the second time to figure out what was going on and I thought the pistons were sticking .....I pressed the brakes a few times to get the pistons out and my thinking to unstick them.....could I have done any damage then??

I am wondering could I have messed up the MC? or is this something to do with the ABS?? No lights are coming on.....car rolls fine.....but when you put the brakes on....it starts jumping (catching and then not catching) pulsating pretty violently....definitely not safe to drive.

 

[LittleCaesar]

Take them back to the Zone and get another pair, then start from scratch. For the first five miles after replacing them, go easy on them.

You did grease the slide pins correct?

 

[sacsr]

yes pins have been greased

 

[sacsr]

Ended up being the one of the rotors was not seating well and was causing all the problems....had the rotor milled and now it is fine.....

Hard to believe I had that much pulsating from that one rotor.....even my friend that is a mechanic and helped me in the end was surprised......

Good news it was not anything major......

 

[pauls4runner]

MOST of the time, pulsating only while on the brake pedal is a rotor issue. thats good that you figured out what the issue was. occasionally the ABS system will cause a pulse if their is iir in the ABS unit or an electrical issue but it is not very common that an ABS issue will cause a pulse. And even with new rotors, if someone overtorqued the lug nuts, that can cause the rotor to warp, warping isnt always noticeable to the eye but definitely fealt on the brake pedal

 

[LittleCaesar]

Good to hear.

I hate that almost all rotors now are made in the PRC. Quality control seems to be lacking over there in the factories.