6th Gen ('00-'05): Brake pulsating
Thread Starter
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Joined: Oct 2013
Posts: 3
Brake pulsating
I have a problem I have replaced brakes and rotors on my 2002 3.8 series II with the best napa sells and I still have some pulsating in the pedal I have bled the brakes manually and with a snap on scanner it has gotten better but still has some at high speeds what can I do to fix problem
I'm venturing a guess,
You didn't either use new rotors...or if you did..
Then you obviously contaminated the pads thus causing the pulseing. You need to get the rotors turned or replaced along with new pads!
If you bought the rotors new...
Did you use brake kleen on them before you installed them? (the rotors) there is a protective greasy film on them from the factory to prevent corrosion.
You didn't either use new rotors...or if you did..
Then you obviously contaminated the pads thus causing the pulseing. You need to get the rotors turned or replaced along with new pads!
If you bought the rotors new...
Did you use brake kleen on them before you installed them? (the rotors) there is a protective greasy film on them from the factory to prevent corrosion.
Whens the last time you changed out all the brake fluid?
Maybe you have a bent rim? or a bad tire? (Out of round)...
Did the pulseing just recently show up?
Or were they pulseing immediately after changing the brake pads and rotors?
Monte Of The Month -- January 2010
Joined: May 2009
Posts: 8,464
From: San Jose, CA
I would be curious to know the answer to David's question above...were they pulsating immediately after being changed, or is this something that just showed back up. In my experience, you CAN warp new rotors in a very short amount of time if you brake hard. Pretty much the only thing that is going to cause pulsing in your pedal is a warped rotor. I had this problem a lot and frequently with my Monte from about 3 months old on...The solution for me was: CRYO treated rotors. They are expensive, but they hold up much better and resist warping. I know I drive hard sometime and that includes braking hard at times...cryo treated rotors solved my warping issues.
The only other thing I can think of that MIGHT be contributing to the pulsing feeling is: a bent rim (as mentioned by David) or a balance issue with your tires.
That being said, i'll again say, rotors are almost always the cause of a pulsing brake pedal.
The only other thing I can think of that MIGHT be contributing to the pulsing feeling is: a bent rim (as mentioned by David) or a balance issue with your tires.
That being said, i'll again say, rotors are almost always the cause of a pulsing brake pedal.
Joined: Apr 2010
Posts: 12,590
From: Mentor, Ohio
One item being overlooked.... What type of pulsing.... You can have ABS pulsing with perfect rotors (typically due to a faulty wheel speed sensor and it may not set a code).
Or you can have warped rotors....
ABS pulsing can be determined by:
- You hear the ABS pump operate as you brake
- You record drive data and review the 4 wheel speed sensors frame-by-frame for one that changes speed from the rest (normally one hits 0 MPH before the rest or it lags at 1 MPH when the rest his 0 MPH). This would also tell you which speed sensor needs replaced.
- I believe there is a fuse for the ABS system (check your owner's manual). Car off, pull the fuse. Start the car, take it for a drive (the ABS light will be on and probably the trac light as well, no worries, it's because you pulled the fuse).
So, we need to know if this is a mechanical brake pulse or an ABS pulse. If it's mechanical:
- Even with new rotors on all 4 wheels, does not mean one is messed up.
- Perhaps a caliper is not functioning properly (perhaps it's applying the pad ****-eyed).
- Could be a hanging caliper.
- Recheck pad wear and rotor wear, see if anything is out of whack (like one set of pads worn more then it's counter part on the other side of the car or pads are wearing with an extreme angle to them).
Or you can have warped rotors....
ABS pulsing can be determined by:
- You hear the ABS pump operate as you brake
- You record drive data and review the 4 wheel speed sensors frame-by-frame for one that changes speed from the rest (normally one hits 0 MPH before the rest or it lags at 1 MPH when the rest his 0 MPH). This would also tell you which speed sensor needs replaced.
- I believe there is a fuse for the ABS system (check your owner's manual). Car off, pull the fuse. Start the car, take it for a drive (the ABS light will be on and probably the trac light as well, no worries, it's because you pulled the fuse).
So, we need to know if this is a mechanical brake pulse or an ABS pulse. If it's mechanical:
- Even with new rotors on all 4 wheels, does not mean one is messed up.
- Perhaps a caliper is not functioning properly (perhaps it's applying the pad ****-eyed).
- Could be a hanging caliper.
- Recheck pad wear and rotor wear, see if anything is out of whack (like one set of pads worn more then it's counter part on the other side of the car or pads are wearing with an extreme angle to them).
Thread Starter
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Joined: Oct 2013
Posts: 3
It has been around a while I changed rotors for the first time with slotted and drilled rotors from napa and put ceramic pads on them I run that for about two years or so and turning rotors when pulsating returned I have changed wheel bearing on driver side and have replaced both wheel bearing harnesses now on this go around I could not turn rotors any more so I got the best napa sold like I said and that took alot out of it but still some there I might be rough on them but I know there is something out there that can give me stopping power I need . I might try CRYO treated rotors when its time to replace these ones thanks for all the help
