Anti Lock brake warning light on 91 Olds Custom Cruiser..

I was driving the 91 Oldsmobile home,and the anti-lock brake warning light started to glow. The wagon drives OK, and seems to stop fine. What should I look for?

 

The first question is this: Was you wagon part of the General Motors recall for defective ABS computers? Is, and if it was not done, TOW it to the dealer. Stop driving it immediately. The computer can leave you with no brakes at all. One of my friends had this on a Blazed. He found out the hard way, after his front bumper rearranged the passenger side of a Honda. Other than that, there are a couple of things. The centre mount brake lamp can trigger the warning. It could be a defective sensor, a defective wiring lead, a bad ground or a defective computer. If it is electronic, it should give a diagnostic code.

 

Thanks, I look it over tomorrow. The wagon has 317,000 miles on it,so it's done alot of stopping over the years...

 

There were no recalls or TSB's for brakes on the '91 Custom Cruiser so don't worry about that.

You can access the ABS diagnostic trouble codes with an OBD 1 scan tool or can do it manually by grounding out the H terminal on the ALDL connector and reading the ABS light flash codes. Best to have a factory service manual for the procedure and codes, the codes are probably online someplace if you don't have a manual.

 

also check the inside of the front brake rotors for corrosion on the inside where the sensor monitors rotor movement. caking of rust and scale can make it so the sensor doesnt see the gap in the teeth of the rotor making it useless.

 

yep, those rotors get a nice build up for rust and crud.
a good thing to do is remove the rotors and clean the ABS ring with a little wire brush. i use a brass bristle one but have never been told thats what to use.
while the rotor is off take some masking tape and stick it on and off of the sensor to clean small metal partilces from it.
regrease your wheel bearings before reassebmling and see if that helps.
i just did this on my black wagon last night(cept i added new bearings, races, brakepads, brake hardware and had the rotors resurfaced.)
the abs light has been coming on lately and after test driving once i was done, it seems to have cured it.