speed_demon24

Today when I was driving my car in the rain, at low speeds the ABS kept kicking on at low speeds when I was braking, usually around 5mph. I'm not braking even close to hard enough to lock up the wheels, so there's no chance they are locking up. When it would kick on, the car wouldn't brake as good since its releasing brake pressure. I has never done this before, and like I said there is a 0% chance I'm locking up the wheels. I tried the brakes out at 30mph and the ABS seemed to work fine, but at low speeds its acting up.

razor02097

My dad's 99 blazer does the same thing... Just to help you out I replaced the rotors and pads already and cleaned the ABS ring. It didn't help. If someone can shead some light on this it would be nice.

Dave89IROC

you need to look at the wheel speed reading with a scan tool


if one of the wheel speed sensors is reading lower then the rest, the ABS will actuate when you apply the brakes(brake switch input is one of the requirements for actvation), as it thinks there is lock-up starting

CamaroSS30thAnn

clean all ur wheel speed and abs sensors,

ive read plenty of posts on here expalining the same problem , i have had this problem to , but this should help alot

speed_demon24

How do I clean the sensors? Just where they plug into? And are there any other sensors besides the ones on the wheel bearings?

Guest47904

Was there any indication on the dash the ABS was coming on? Such as the "LOW TRAC" light?

speed_demon24

Yep.

Guest47904

The problem is entirely from the water and will be no way to compensate for it. See it on cars everytime it rains. Search for TSB's and there may be a help tip.

z28 justin

I have this problem as well, only at low speeds then it'll kick on. I'm in the process of checking my wheel speed sensors right now. I have a 95 Z and the book I have says there should be 2 in the rear, but there is only 1 in the middle. Where are they plugged into in the front? And where do they all plug into on the other end?

Injuneer

You will only have two rear wheel speed sensors if your car has the optional traction control system. Without it, you get a single ABS sensor on the differential housing.

Shoebox has a diagram of the non-TCS ABS system on his website:

http://shbox.com/1/ABS_schematic.jpg

z28 justin

Thanks, forgot what the website was for shoebox

Marc 85Z28

This is a common problem among GMs SUVs, and some Fords also. They all use the same style ABS system.

Basically the ABS module is seeing a lockup condition from one or both of your front wheels. This is due to a sensor reading incorrectly from improper air gap. Corrosion builds up over time on the hub and moves the sensor further away from the reluctor ring, creating a "dropped signal" that is present at or below 5mph, and is often intermittent.

To remedy this, you will need to carefully remove both front wheel speed sensors from the hub. With a metal file and some sandpaper file the sensor mounting pad until the rust is removed. You'll want it free of all corrosion, clean and level. Try to avoid contaminating the bearing with dirt/debris. If the rust is built up pretty bad, lightly tapping it with a ball peen hammer will chip all the rust away. Reinstall the sensors.

speed_demon24

It does it wet or dry, and just started doing it.

speed_demon24

Thanks, I'll give that a try.