1993 ABS Pump Issue?
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From: Maryville Tn
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1993 ABS Pump Issue?
Got a issue with my '93. My rear calipers aren't applying enough pressure to keep the pads against the rotors and I've noticed I haven't heard the ABS pump make it's self check noise when I backed the car out of my garage. The only thing have done to the car his changed the rear brake pads, and last year I had the brake fluid changed. Any input would be appreciated. This is a first for me. 
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From: Minneapolis Mn
AFAIK the ABS pump is not going to increase any pressure through the braking system, only modulate it. It could be possible to have something internally within the pump preventing full pressure to the rear half of the system. The abs pump would not be the first item I'd go after for your problem, it could be related but would be much lower on the list IMO.
My belief would be either the calipers are hanging up or more likely you have some air in the rear half of the system that either was not fully bled or got into the system. That's where I'd start my examination. Good luck.
My belief would be either the calipers are hanging up or more likely you have some air in the rear half of the system that either was not fully bled or got into the system. That's where I'd start my examination. Good luck.
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I believe that if I didn't have the ABS cycling/self check I'd maybe check the related diagnostics first. There should certainly be codes of sorts that could be extracted. I would think that there would be DIC lights indicating ABS/ASR potential problems. I don't have a '93 FSM and I don't have a car with ASR/ABS so I can't help much. A '94 changed substantially in the diagnostics and code reading so what I have in an FSM isn't going to apply to a '93.
I do believe that it's potentially a hydraulic problem but I'd exhaust maybe the effortless diagnostics on the ABS/ASR first. Does the parking/e-brake function properly and exert sufficient force to hold the weight of the car "on grade"?
I agree with "hcbph" as to the likely situation but I might like to keep my "hands clean" as long as possible. ABS/ASR codes requires not getting dirty as a rule. Gloves/mittens work when it comes time to maybe "getting dirty".
I do believe that it's potentially a hydraulic problem but I'd exhaust maybe the effortless diagnostics on the ABS/ASR first. Does the parking/e-brake function properly and exert sufficient force to hold the weight of the car "on grade"?
I agree with "hcbph" as to the likely situation but I might like to keep my "hands clean" as long as possible. ABS/ASR codes requires not getting dirty as a rule. Gloves/mittens work when it comes time to maybe "getting dirty".
Last edited by WVZR-1; Apr 7, 2015 at 09:07 AM.
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Got a issue with my '93. My rear calipers aren't applying enough pressure to keep the pads against the rotors and I've noticed I haven't heard the ABS pump make it's self check noise when I backed the car out of my garage. The only thing have done to the car his changed the rear brake pads, and last year I had the brake fluid changed. Any input would be appreciated. This is a first for me.
Thread Starter
Moderator Emeritus
Joined: Jun 2002
Posts: 46,133
Likes: 111
From: Maryville Tn
CI 5 thru 12 Veteran
St. Jude Donor '09 thru '23
NCM Sinkhole Donor
I do believe that it's potentially a hydraulic problem but I'd exhaust maybe the effortless diagnostics on the ABS/ASR first. Does the parking/e-brake function properly and exert sufficient force to hold the weight of the car "on grade"?
I agree with "hcbph" as to the likely situation but I might like to keep my "hands clean" as long as possible. ABS/ASR codes requires not getting dirty as a rule. Gloves/mittens work when it comes time to maybe "getting dirty".
I agree with "hcbph" as to the likely situation but I might like to keep my "hands clean" as long as possible. ABS/ASR codes requires not getting dirty as a rule. Gloves/mittens work when it comes time to maybe "getting dirty".
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Joined: Aug 2013
Posts: 4,429
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From: Minneapolis Mn
Just realized I didn't put down the 2d part of my comments (got interrupted). The problem is in 2 parts: weak brakes and abs issue.
IMO the first thing is get the brakes working correctly then worry about the abs. Brakes without abs still work, brakes not working with abs still don't work.
Once the brakes are corrected, check the fuse on the abs then check the FSM for diagnostics. I don't know for sure, but there might be codes for abs but you'd have to check the FSM to be sure.
IMO the first thing is get the brakes working correctly then worry about the abs. Brakes without abs still work, brakes not working with abs still don't work.
Once the brakes are corrected, check the fuse on the abs then check the FSM for diagnostics. I don't know for sure, but there might be codes for abs but you'd have to check the FSM to be sure.
Thread Starter
Moderator Emeritus
Joined: Jun 2002
Posts: 46,133
Likes: 111
From: Maryville Tn
CI 5 thru 12 Veteran
St. Jude Donor '09 thru '23
NCM Sinkhole Donor
Just realized I didn't put down the 2d part of my comments (got interrupted). The problem is in 2 parts: weak brakes and abs issue.
IMO the first thing is get the brakes working correctly then worry about the abs. Brakes without abs still work, brakes not working with abs still don't work.
Once the brakes are corrected, check the fuse on the abs then check the FSM for diagnostics. I don't know for sure, but there might be codes for abs but you'd have to check the FSM to be sure.
IMO the first thing is get the brakes working correctly then worry about the abs. Brakes without abs still work, brakes not working with abs still don't work.
Once the brakes are corrected, check the fuse on the abs then check the FSM for diagnostics. I don't know for sure, but there might be codes for abs but you'd have to check the FSM to be sure.
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