Hey, we got an ice storm up year last night and everything got coated pretty good. Anyhow, when I was driving this morning, my rear antilock light came on when I braked. Any idea why this is? When I got to my destination, I shut the truck off and restarted, and the light went off. And when the light was on, and I braked, I could tell the difference. Anybody know if I damaged anything?

 

sorry i cant answer your question, but a similar thing happened to me not long ago. i was driving and had to stomp on the brakes suddenly and when i stopped i noticed the rear antilock light on. now everytime i start the truck the light is off until i do any kind of heavy braking, then it comes on (turns off again if you restart the truck). i dont notice any difference in braking performance, though

 

Sounds like it could be a faulty sensor if you have noticed no difference in braking performance. If the sensor is not ****ioning properly it can not sense wheel spin from the exciter ring in the rear end that rotates with the pinion gear. When it craps out it should send a warning via the brake light indicator.

I'm not sure on the test procedure, maybe StarngeRanger could help out on this one.

 

I know the other night a woman (off course) cut me off and I had to slam o nmy brakes, and they did not seem to be "antilock, because they locked up and I left 2 black marks about 10 feet long. BTW the truck stops on a dime with these big tires. I never really wanted to slam on the breakes to see how fast I would stop, but now I know that they do stop me fine. Also my light came on, but after that I never saw it again. I did add some brake fluid when I got home. Maybe when you slam on them and the fluid shifts, the sensor does not pike up anything and it comes on. Maybe they arent related at all, but all I know is the light has not come on again.

 

I don't think it would be a bad wheel speed sensor because the computer monitors that all the time, not just under heavy braking so it would turn on the light when your driving normally if that was a problem, plus that sensor is also used as the speed sensor for your speedometer. It is normal for the light to come on when the abs is activated, but it should go off right away.

Maybe it's a problem with the RABS actuator itself?

The light will reset itself when you turn off the ignition. When the light is on you can ground a wire in the RABS diag connector to get flash codes out of it. You have to do that before you turn the key off or the codes will be erased.

-Jon

 

It is normal for the light to come on when the abs is activated, but it should go off right away.

If the lamp comes on while driving its telling you there is a problem and abs shuts down. You will have to pull the code on this one (assummimg its a 88) while the lamp is on by grounding the orange/black wire. Usually if it comes on during braking its a bad RAB's valve or fulid level problem.

 

yeah, it should not change the feel of your braking. Most people think that if you have abs you tire will not lock up. This is not true, if all 4 tires are locked up, the abs will not operate. It only sences diffrence in speed between the tires. In these older trucks the rear abs is kinda a joke but then again, the light sucks to see. When I put the locker in my truck I accidently marred a tooth on the exciter ring, now when maintaining speed the rear antilock light comes on, it sucks.

 

i had that problem with my fruck a few weeks ago. and with mine, the emergency brake light came on too. how much brake fluid do you have in the master cylinder? i looked at mine and there was a little less than half in there. so i filled it up to the "max" mark. also, i jiggled the little plug that goes into the bottom of the resivior.

 

It hasn't happened again, but, now that it has warmed up, I'll give all the fluids a check.

 

sorry for diggin up an old thread from the grave but is there a website where I can buy an exciter ring or do I need to get it from the dealer, i've searched everywhere

 

What's wrong with your original? Unless it's visibly damaged, it can be reused.

 

I bent it removing the ring gear

 

Well, if you can't find one at a decent price, I have a good used one that you can have for $12 delivered. E-mail me if you want it.