ABS separate computer under dash?
vljenewein
01-16-2005, 09:13 AM
Ok.. I did a search first, and now posting this question. I was told that the ABS Antilock Braking System has a control module aka computer component, under the dash, drivers side near the steering column. Is this true? 1993 Buick PA Ultra by the way.
Replaced the faulty ABS hydraulic system under the hood (4-valve/brakelines, and just under the automatic leveling compressor). Original one I had malfunctioned and caused the LF tire to become locked at certain times. Tap on the side of the unit lightly with a ball peen hammer and it would release... sort of. First ABS Unit I replaced was faulty and the light would come on and the ABS system would allow the car to slide on ice (was from a salvage yard). Second ABS Unit I got from another salvage yard actually works. Dash light goes off, and the ABS system works on icy surfaces.
However.... I've still got an issue with the LF brake getting excessivly hot. Drive it a few miles and it's not noticable. Drive it for about 15 miles and the wheel is very hot.
A while back the LF wheel got very hot and took it to my mechanics. They replaced the rubber hose to caliper, caliper, rotor, pads. The hose was cracked and probably not letting fluid back out again. Probably was the ABS starting to act up. It still had the "original" ABS Unit in it. Drove it to town, stopped at the gas station and the LF locked up like no tomorrow. My mechanics called a tow vehicle to bring it back out there. They checked it out and the computer pointed to the ABS unit. Tap on the side of the unit and it would release. I drove it a couple of days to work and back (about 6 miles) and the brake got pretty hot again, and finally took it back to them. Tapping on the unit DID unlock the lock condition. Then I got a second hand unit from a salvage yard that they used to replace the original.
Put in the 2nd ABS Unit, (defective one that the dashlight showed), and drove fine, but the light stayed on. It got fairly hot when I drove it to town and back (about 11 miles there and 11 miles back). Took it back after I found another ABS and they replaced it, but still having issues with the LF wheel getting hot. I suspect the Caliper that they replaced may have gotten damaged from the heat, or excessive heat, of the "Original" unit not working properly and may have done damage to the seals of the caliper??
The mechanics even had the new rotor "planed" to true up if there was any excessive runout.
Brakes were bled well in all cases. The Mechanics have been very helpful, but also as confused as I am about this one. Since the first trip there to have all the stuff replaced, (caliper, rotor, hose, pads + labor which come to $180.00) they have refused to take any more money even after changing out the ABS units, and having the rotor planed, until I'm satisfied and the issues are solved. That was pretty nice of them.
Replaced the faulty ABS hydraulic system under the hood (4-valve/brakelines, and just under the automatic leveling compressor). Original one I had malfunctioned and caused the LF tire to become locked at certain times. Tap on the side of the unit lightly with a ball peen hammer and it would release... sort of. First ABS Unit I replaced was faulty and the light would come on and the ABS system would allow the car to slide on ice (was from a salvage yard). Second ABS Unit I got from another salvage yard actually works. Dash light goes off, and the ABS system works on icy surfaces.
However.... I've still got an issue with the LF brake getting excessivly hot. Drive it a few miles and it's not noticable. Drive it for about 15 miles and the wheel is very hot.
A while back the LF wheel got very hot and took it to my mechanics. They replaced the rubber hose to caliper, caliper, rotor, pads. The hose was cracked and probably not letting fluid back out again. Probably was the ABS starting to act up. It still had the "original" ABS Unit in it. Drove it to town, stopped at the gas station and the LF locked up like no tomorrow. My mechanics called a tow vehicle to bring it back out there. They checked it out and the computer pointed to the ABS unit. Tap on the side of the unit and it would release. I drove it a couple of days to work and back (about 6 miles) and the brake got pretty hot again, and finally took it back to them. Tapping on the unit DID unlock the lock condition. Then I got a second hand unit from a salvage yard that they used to replace the original.
Put in the 2nd ABS Unit, (defective one that the dashlight showed), and drove fine, but the light stayed on. It got fairly hot when I drove it to town and back (about 11 miles there and 11 miles back). Took it back after I found another ABS and they replaced it, but still having issues with the LF wheel getting hot. I suspect the Caliper that they replaced may have gotten damaged from the heat, or excessive heat, of the "Original" unit not working properly and may have done damage to the seals of the caliper??
The mechanics even had the new rotor "planed" to true up if there was any excessive runout.
Brakes were bled well in all cases. The Mechanics have been very helpful, but also as confused as I am about this one. Since the first trip there to have all the stuff replaced, (caliper, rotor, hose, pads + labor which come to $180.00) they have refused to take any more money even after changing out the ABS units, and having the rotor planed, until I'm satisfied and the issues are solved. That was pretty nice of them.
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