ABS light and Brake light both come on at the same time. shortly after I lose all my brakes and the pedal goes all the way to the floor, not rock hard. I have checked under the hood when this happens and the reservoir is over full as in the pump is not pressurizing. Every once in a while I can see the pump kick on and the fluid in the reservoir starts to go back down to normal and the ABS and Brake lights go off and brakes are fine again for a short amount of time, then it happens again. I'm guessing this is the pump going bad. Just wondering if anyone else has some input on this. Maybe its more likely something else? Could it be the ABS pump relay causing problems? Or something else? I don't want to start throwing money at it not knowing what it is.

hi, I would first start at relays and fuses - replace with known good ones and see if your issue changes

_________________
poverty forces one to do unorthodox things

2000 SSEi
past rides:
1996 SSEi
1992 GTP
1987 Grand Am

I have replaced the fuses under the steering column marked as abs and brake fuses. So they are all good. I work at an auto parts store and I am listing an ABS relay for my vehicle but I have no clue where it is located. It says nothing in the owners manual and I cant find a location on google either. I have found about 6 different relays that look exactly like the one they show for the abs relay so I dont want to just start guessing.

If you have 6 relays that are exactly the same, I would think that you can play musical relays to see if an issue moves to a different system.

I never did like this ABS system. It's expensive and needy. I hope you can track down the issues with it though.

_________________
~Randall~


1993 Buick Park Avenue - 197k - Some odds and ends done - Simply won't die
1994 Buick Regal - 78k - Bone stock - Always ready for a good kicking
1990 Oldsmobile 88 - Gone to a better place

So last night I tried doing a test lead straight from the battery to the pump motor. Didnt kick on at all, and yes it was grounded. Does that still leave the relay in question or does that rule the relay out?

page 6-59 of manual has fuses and breakers

google ......just give me the dam(n) manual...... no brackets

_________________
poverty forces one to do unorthodox things

2000 SSEi
past rides:
1996 SSEi
1992 GTP
1987 Grand Am

I found 2 different fuses in the manual which are both located in yhe fuse box below the steering column. One is electric brake (pump), the other i ebc or electric brake control. I replaced both with brand new ones just to be safe but the problem still exists. The relay i found in my parts lookup at my work is called an abs/antiskid relay, which is a 5 pin relay with a plastic housing around the pins instead of the normal open pinned relays. That is the one that i have searched google for hours to locate on my car. There is a plastic cover up by the firewall by the ac dryer that im going to take off and see if there are more relays there. Side note: today i took both fuses out of the fuse box that have to do with the electric brakes just to see if i could maybe bypass the abs system and have it revert back to normal brakes. Within a couple minutes the pedal got hard as a rock and still no brakes, i then put in the one fuse for the electric brake (pump) and after a few minutes the pedal got soft and went all the way to the floor and still no brakes. Both abs, and brake lights have been on this whole time i should mention...so i then took out the fuse for the pump and put in the fuse for the electric brake control...now this may just be a fluke but after letting the car sit there and run for a few minutes, the brake light went off and abs light stayed on. And i had brakes all of a sudden again. Havent had alot of time to test to see if this is actually a fix and just bypasses the abs or not. But as of right now, the brakes are working. But this problem comes and goes as it is. One day i will wake up in the morning and both lights go out and i have brakes then halfway through the day the lights come back on and i lose everything again. So im still thinking the pump is going out and every once in a while it decides to kick on and give me brakes for a few hours. I will give another update after a few days though.

Also I have been checking my cataloging at work on abs vs non abs for the 1988 bonnevilles. It looks to me like the rotors calipers and hoses in the front are all the same, as is the drums and hoses in the rear. So why couldnt i find a donor 1988 bonneville that didnt have abs at a junkyard and get the master cylinder and brake booster, and mount it up in place of the hydraulic abs unit? It looks like the hydraulic unit still mounts up with a 4 bolt pattern just like the standard brake booster. Im sure i would need to figure out how to mount it and eliminate all the extra hydraulic, and abs junk, but is that possible? And if it is how big of a project would I really be getting in to? Honestly the car was given to me by one of our delivery drivers. It has just barely over 100,000 miles and everything other than the brakes are in perfect condition. She had someone redo the whole a/c system a few weeks before. And i love the 3800 motors. Not bad as far as power for the little 6cyl, and amazing gas milage. If i can get this brake thing worked out it would be an awesome car to take pretty much anywhere. (Yea its old) but the 3800 motors in my opinion are really reliable and easy to work on. Its just too bad gm had to put in this hydraulic system for this year. Kind of a terrible idea for someone to be able to drive down the road at 60 or 70 mph and lose there brakes rather suddenly...i did notice the fwd buick, olds, and cadillac of that year also had the option for that same abs hydraulic system, so there is that route also. But i havent had much luck finding any of those cars in that specific year at my local wrecking yards.

I believe you can grab a booster and master cylinder from a donor vehicle, and convert to regular brakes without too much hassle. I believe you may need to modify the brake pedal piston some, but I don't know the exact details on that. I also believe that there is only one brake line going to the rear instead of two for the regular system, so you may need to add another line going to the rear.

It is entirely possible to ditch the ABS, and in that application many do, and have never looked back. Last time I looked, a unit from rock auto was over $1k, plus core.

_________________
~Randall~


1993 Buick Park Avenue - 197k - Some odds and ends done - Simply won't die
1994 Buick Regal - 78k - Bone stock - Always ready for a good kicking
1990 Oldsmobile 88 - Gone to a better place

You have the Teves (Mark II?) system like I have in my '90 SSE. I also had it in my '88 Toro and a '90 Jag XJ6. Yup, it was used in many different cars in the late '80s and early 90s. I had a similar issue with my '88 Toro. I salvaged the entire unit for $75 and swapped it out. This solved my problem. I know it was a gamble but it wasn't that hard to do and the junk yards usually give 30 days warranty. I seem to recall a conversion thread in the Toro subsection of the Olds forum. My recollection was that it was not an easy switch.