ABS issue

[extremetimmy]

Hello all, i'm having an issue with the ABS in my '96 1500. when i get down to about 10 mph, the ABS kicks in even though all the tires are rolling. i figure it's one of the sensors, but i'm uncertain which one. what i would like to know is how can i figure out which sensor it is? thanks

[zario]

your gonna have to take it to a dealer or a shop to get it scan, you would never know what sensor is the bad one until you get it scan since different sensors and symptoms make it turn on, I just hope is not the ABS because if it is the price on that in L.A if you get lucky is no less than $300.00 for a used one and around $900.00 to $1,100.00 for rebuilt or new depending were your getting it from, if you fix the problem come by and let us know what was it good luck.

opcorn:

[CD Smalley]

Let's ask some what should be an obvious question...

Have you changed the size of tires on your truck?

[extremetimmy]

Originally Posted by CD Smalley

Let's ask some what should be an obvious question...

Have you changed the size of tires on your truck?

no i haven't changed the tire size, only recent repair was timing chain, other than that, been driving it.

[extremetimmy]

i think i've figured the sensor to be the left front wheel. other than changing the wheel bearing, is there any way to service the ABS sensor?

[daman]

If you don't have a ABS light coming on how do you know it's a wheel senser?

[extremetimmy]

when the brakes are applied above 10 mph the truck slows in a straight line, once the ABS pump kicks on it begins to pull to the right.

[daman]

Originally Posted by extremetimmy

when the brakes are applied above 10 mph the truck slows in a straight line, once the ABS pump kicks on it begins to pull to the right.

Ok but i still don't see how that tells me it's a wheel senser without a light
coming on????

[extremetimmy]

the ABS system thinks it's working correctly, when in fact it is not. it engages on the driest of roads under 10 MPH, over 10 mph the brakes function correctly. the sensor thinks the tire has stopped moving ( skidding ), when in reality the tire is rolling just fine.

[daman]

Ok i was just wondering because my '99 is doing the same thing and i don't
ever get a light on, i heard it was the ABS pump under the hood,.

usally when a wheel senser is bad it will trip the light......

[southtowniceman]

I've got a '96 Tahoe and had the same problem twice. Your truck must be set up the same.The first time, the dealer said both front hub bearings were bad, and the sensors were picking up on this and sending a false signal to the ABS computer. $400.00/per side to change the hubs. It corrected the problem, but I couldnt feel any play in either of the old bearings. A year or so later, same thing happened again. Knowing full well now that the bearings weren't the issue, I posted on this web site and got some interesting information.Rust forming under the sensor(s).
Not saying your sensor(s) aren't defective, but this is what I did. Do what it takes to remove the sensor from each bearing hub. Mine had one allen head screw holding the sensor in. Be careful not to damage the o-ring on the sensor (special size o-rings) Clean the hub area where the sensor sits, to bare metal, spray a coat or two of cold galvinizing on the area, and clean the mating surface on the sensor and clean the bottom where the coil magnet is. Apply some silicone grease on the o-ring,and reinstall the sensor. My brakes worked perfect after that.
If memory serves me, the mv reading I got from the sensor when I spun the wheel, was around 200mv before cleaning. Once cleaned and reinstalled the sensors put out somewhere around 500-600mv. Hope your is a cheap fix like mine was.
Tom

[daman]

Thanks for your input!!!

so did you ever get a ABS light coming on????

also where did you check your reading on the back of the senser unpluged???

[southtowniceman]

Neither time did I get an ABS light, just pulsing of the brake pedel when slowing to a stop (5-6mph). Unplug the sensor and fashion a way to connect the meter probes to the pins inside the connector, and spin the wheel, you should show an ac mv reading. There's not much room inside the connector, but it can be done. If you do a search in the Tahoe forum, back maybe 6 months, you should find the information I received from one of the posters on that forum.

[daman]

Again thanks!!!!