97LT4SS

Looks as if I finally solved my MAF problem but now the Low Trac light goes on whenever I attempt to stop fast. I can feel the front brakes skipping or bouncing. Tires are not loosing traction and I'm not skidding nor am I driving in the rain, not that the car has ever seen rain. Brake light is NOT on and Low Trac comes on under moderate brake pressure.

My car does not have Traction Control and in all honesty doesn't seem safe to drive at this point. The Front brakes are 13" Baer Track set-up with 10k miles. Car doesn't pull or shudder. Any ideas on where I can start because if I have to stop quickly it's not going to happen. The Low Trac light has come on in the past but my braking performance has never been an issue until now.

Again, brake light has never come on, just Low Trac appears momentarily and then turns off.

Thanks

derrickgott007

My low trac light comes on when i hit a bump every now and then. I don't have traction control on my 97 Z28 and I just replaced the brakes last week. I'm thinking its maybe a loose wire or sensor that is causing it. It doesnt bother me much because even when doing a burnout the low trac light won't come on... So I'm guessing mine is not working....

97LT4SS

Problem is it's becoming a struggle to stop quickly just on flat pavement. Not sure what to check, I'll have to pull the front wheels and inspect.

Injuneer

The "LOW TRAC" light is used in the non-traction control cars to indicate the ABS has been activated. You may perceive that as poor braking performance, but what it is doing is modulating the pressure in the three brake circuits to prevent wheel lockup.

If the performance with the ABS system engaged has deteriorated, might be a good idea to have the ABS computer (EBCM) scanned for trouble codes.

I'll move this to "Supsension, Chassis and Brakes" forum, since its not an "engine" question.

97LT4SS

Fred, thanks for moving to the correct location. I tried deleting my original post in the LT1 engine section but was too late, sorry.

Ron78Z&01SS

Pull the connectors at both front wheels and shoot the male & female ends with elect contact cleaner. Do the same to the connector at the top of the differential. Also remove the magnetic pick-up/sensor from the top of the diff as well and clean any "crud" off of it.

I had a similar problem on my 96 that yo had, but my "ABS Inop" light would occasionally come on as well. I did all of the above about a year ago and the problem never came back.

97LT4SS

Thanks for the info. I have the spray, but car has never seen rain so not sure how the sensors could get dirty in the first place. O'h well cleaning never hurts. Thanks again

Guest47904

The problem is not the lack of a sensor signal. If the sensors were the problem, you would have an "ABS INOP" light. And it would come on once the vehicle moves and go off once shut off until it moves again. This would be an example of a "soft" code. So cleaning the connectors will not help you.

I think the EBCM is seeing a difference in rotor diameter since the front rotors were changed to a different size and the feedback signal from the reluctor is misinterpreted as a difference in wheel speed. This then activates the ABS system every time the brakes are applied.

rngilliland

Changing rotor size doesn't affect the abs. The reluctor and abs sensor are in the hub.

Injuneer

Is the problem you are having more like a case of the ABS engaging suddenly at the very end of a moderate stop, making the car take longer to stop than you anticipated? I've had that happen, and it was related to a problem with the rear axle sensor not being set correctly (Strange rear and asjustable sensor). But I suspect that excessive metal particle buildup on the rear axle sensor will have the same effect. As the rear axle reluctor speed approaches "0", the crud on the sensor causes the signal to be lost, the EBCM thinks the rear brakes have locked up, and it actuates the ABS system.

I'n not sure why front rotor size would have anything to do with the signal.

97LT4SS

Fred, yes ABS seems to be engaging too quickly during a moderate stop. But, feels as if the front brakes and not the rear are trying to lock-up when traction is not an issue.

Motive 4.10's were installed 5 years ago but I haven't had any issues with the brakes until now. Not sure if that additional info helps or not.