ABS problem I think!!! Urgent, Please Help.
Thread Starter
Instructor
Joined: Apr 2009
Posts: 242
Likes: 1
From: Pictou Nova Scotia
ABS problem I think!!! Urgent, Please Help.
I just completed the harmonic balancer swap on my 99 FRC. To remove the steering rack I disconnected the wire going to the back of the front driverside spindle. I battery was disconnected. The balancer install went good but now when I touch the brakes fairly hard it sounds like the ABS is pounding on the front driverside wheel. I can brake gently and not hear any noises. Any ideas good or bad is welcomed. Is there something the dealer has to reset? Is this wire the ABS or Active Handleing? OBD2 reader or DIC aren't spitting out any info.
Tech Contributor
Joined: Oct 1999
Posts: 41,058
Likes: 9,820
From: Charlotte, NC (formerly Endicott, NY)
An OBD2 reader is a waste of effort. If the DIC doesn't show any codes there probably isn't anything wrong with the ABS. When you hear this noise does a message appear on the DIC? If ABS is active you would see: ABS ACTIVE .
If you don't see that message something else is happening. If you do there could be a problem with the brake system at that wheel. Find yourself a nice quiet road where you can get up to 40 mph or so and slam on the brakes to see how ABS activates. Full ABS activation is a violent event. The car will vibrate as the ABS modulates the pressure at each caliper to keep the wheels at the proper amount of slip and the brake pedal will vibrate as well as another form of driver feedback. If you have never done it before you should experience it so you know what is happening if you ever make an emergency stop, just make sure everybody's seat belt is fastened and nobody is driving behind you. ABS of one wheel indicates that wheel is locking before the others. That could be due to a road surface, brake pad, brake rotor, brake or caliper issue. There could be an issue with the ABS system but it is much lower on the probability list.
Bill
If you don't see that message something else is happening. If you do there could be a problem with the brake system at that wheel. Find yourself a nice quiet road where you can get up to 40 mph or so and slam on the brakes to see how ABS activates. Full ABS activation is a violent event. The car will vibrate as the ABS modulates the pressure at each caliper to keep the wheels at the proper amount of slip and the brake pedal will vibrate as well as another form of driver feedback. If you have never done it before you should experience it so you know what is happening if you ever make an emergency stop, just make sure everybody's seat belt is fastened and nobody is driving behind you. ABS of one wheel indicates that wheel is locking before the others. That could be due to a road surface, brake pad, brake rotor, brake or caliper issue. There could be an issue with the ABS system but it is much lower on the probability list.
Bill
Le Mans Master
Joined: Nov 2005
Posts: 6,993
Likes: 25
Last brake job I did on a truck I have, I got new front rotors. After I put the who;e thing back together I went for a test drive and as soon as I tried to stop all hell broke loose. ABS started pulsing like MAD. Put the old rotors back on and the problem went away. Turns out, the ABS ring on one of the new rotors was tilted off by about the thickness of a matchbook cover fooling the abs sensor and setting off the ABS. No warning or ABS lights.
Check the sensor you unplugged for a bad conection is where I'd start.
Check the sensor you unplugged for a bad conection is where I'd start.
Tech Contributor
Joined: Oct 1999
Posts: 41,058
Likes: 9,820
From: Charlotte, NC (formerly Endicott, NY)
Last brake job I did on a truck I have, I got new front rotors. After I put the who;e thing back together I went for a test drive and as soon as I tried to stop all hell broke loose. ABS started pulsing like MAD. Put the old rotors back on and the problem went away. Turns out, the ABS ring on one of the new rotors was tilted off by about the thickness of a matchbook cover fooling the abs sensor and setting off the ABS. No warning or ABS lights.
Check the sensor you unplugged for a bad conection is where I'd start.
Check the sensor you unplugged for a bad conection is where I'd start.
Bill
