SaabCentral Forums banner

1 - 10 of 10 Posts

·
Registered
1993 900 turbo Convertible
Joined
·
20 Posts
Discussion Starter #1 (Edited)
ABS light was on (no others). Brake pedal was pretty hard and didn't have much stopping power. I suspected the pump, which my Saab guy confirmed.
Now, the brake fluid light is on as well, which is kind of weird, because I would have suspected it earlier (fluid level is normal). ECU must be working because it turned on the lights, right? Wondering if anyone has any tips because the car is now feeling VERY hard to stop. I know the pedals are normally hard, I've had two pre-90's 900s and other old cars. I like that about them, but either I need to work out HARD on one leg, or the car isn't safe in an emergency stopping situation.
Do I have to get the entire ABS module/pump replaced for this particular issue to be remedied? Is there something else I can do short of that to get more power? Obvi, the pump is hard to come by and an expensive fix. Is it safe long term to drive without the ABS, the stopping issue aside?
Am I now braking on all 4 wheels minus the ABS or just front? Mechanic says all 4, but I was under the impression it was just the front. Not only does this not stop on a dime, it doesn't stop on a quarter, a dollar, a safety deposit box even! Maybe half the width of the bank...
Any help would be greatly appreciated!
I've got a 93 900 turbo convertible, automatic
 

·
Registered
Joined
·
7 Posts
The red brake light means an internal failure in you brake booster assembly. I ran into the same problem and my fix was replacing the brake accumulator (black dome thing next to the reservoir) but that was over a decade ago. You definitely have a brake vacuum issue since the pedal is extra hard. I don't think a used part will solve your issue. You may be able to get away with converting the an older style brake booster that pulls vacuum from the engine instead of the electronic components and getting rid of the dash bulbs, but you will also loose your abs that is also currently lost permanently. This conversion is an educated theory and I cannot guarantee accuracy since I haven't done it, yet lol. As far as safety, yes abs is better but honestly 1993 abs systems are not exactly spectacular. I have actually disabled the abs on my 1990 because it interfered more than helped, but I also drove it hard every where back then. Best of luck fellow saaber. Pm me if you want a little more feedback than this post. Also you are braking on all 4 right now. Just with no power assistance. Only prius or other hybrid vehicles that use regenerative braking are the only ones that I aware of that use only front brakes in "failed brake module mode". Also don't mention your inspection guy hooking you up for his safety. I am in texas, the car could be on fire but if all lights work and no red lights on dash you pass (minus emission counties) and his personal license can be fined for passing a car not up to standards. He definitely hooked you up.
 

·
Registered
1993 900 turbo Convertible
Joined
·
20 Posts
Discussion Starter #3
Cool thanks, it's def the pump (could hear it if it were running), so replacing the accumulator won't help, unfortunately.Thanks for the info about braking on all 4, also edited out inspection info in case ;.). If anyone knows any parts numbers or specific parts that could be substituted for a conversion, let me know! Right now I'm searching for a pump but if there's an easier set up to find that I could stick in there, that'd be cool!
 

·
Registered
Joined
·
305 Posts
I think in the USA it's probably a crime to delete the ABS system, but others here would know. It is definitely something that would cause a change in the title of the car. Anyway, I would keep checking the threads on the accumulator thing. It's a common failure. When I did mine I finally found one on eBay and there are folks out there that refurbish them (they hold ~2000lbs pressure). It takes about 5 minutes to replace it.
 

·
Registered
Joined
·
5,883 Posts
Unlikely that removing ABS on a c900 is any sort of problem. ABS was not a requirement on cars until 2005 (somewhere around then) so it's at best a feature like power windows or cruise control. I could see a scenario were a state with annual safety inspections might fail a car for equipment that should be there, but by the same token if it's a convincing swap-out it's unlikely such an inspection station would have anything to tie that feature to that specific car. In Calfornia, for example, there isn't even any mechanism for enforcing this type of modification.

IMO, the most likely scenario for a problem would be in the event of an accident. "Did you have ABS that could have prevented the accident?" Yes, but I disabled it. Not a good look. Would things ever get that far? Maybe... Likely to get that far? Probably not. You'd be at much higher risk in a 2020 Ford than a 1990 Saab. After a certain point an old car is just an old car and expectations are adjusted appropriately.

Further, IMO, the Teves ABS system is such a liability to keep working, I think you might have a case for 100% reliable non-ABS brakes versus relying on a system whose ancient pump, accumulator, or valve body could fail spontaneously at just the wrong minute.
 

·
Registered
Joined
·
305 Posts
Good points. And I think at some point our cars are so old, already >25, that classic auto and antique auto rules come into play. Pretty soon these will all be considered the same as restored classics or hot rods or something that are street legal. Except maybe the airbag laws, that some of us have.
 

·
Registered
Joined
·
5,883 Posts
Airbags weren't required by law until 1999, so c900s are probably safe there as well.

Most vehicle laws apply to new sales or professional work. Relatively few laws control what an owner is allowed to do to his own car. The obvious 800lb gorilla there is emissions laws, but some states also have guidelines for "motor vehicle safety" which may be narrowly or generally enforced. In California, a brake inspection essentially only checks that a car stops in a reasonable distance, in a straight line... as long as you get there, you're done.

I would say the two major gotchas which you can't lose sight of are what lawyers can get a jury to support (the concept of negligence) and legal or civil fallout after a sale. If you sell a 1990 Saab and the buyer wrecks it and blames your modifications, the law or a jury may have something to say about it. These are both HUGE grey areas but worth being aware of IMO. I've spent some time in the legal industry and seen TONS of lawsuits for questionable dealer mods on new cars (like non-stock wheels, or lift kits, etc.) but zero for private party sales. I'm sure there's a line between obvious or disclosed mods and hidden and deceitful ones, but I don't know where it is. :)
 

·
Registered
1993 900 turbo Convertible
Joined
·
20 Posts
Discussion Starter #8
I knew i saw it somehwere about front brakes only. this from the service manual:
If the Iights have come on because of a pressure
drop in the system, neither the power assistance
nor the brake pressure to the rear wheels wiII be
in proportion to pedal pressure. At worst, if no
hydraulic pressure remains, the re will be no
power assistance and no rear-wheel braking. The
front -wheel brakes will still operate normally but
with out power assistance.

Since there is barely any braking power, this may have happened. So now the question I have is if BEFORE only the the ABS light was on and NOW it's ABS and brake lights, is it possible that the pump would be bad but ONLY the ABS light would be on?

This also from the manual :
The ABS (Anti-lock) warning light alone will come
on if the ECU detects a fau lt in the ABS system.
Conventional brakin g power will be available but
the ABS system will be inoperative.

If both of these lights are on, this indicates that
the level in the flu id reservoir has dropped
further or the pressure in the accumulator has
dropped below 105 bar (1523 psi).
The ABS system will be inoperative but reduced
braking effect will remain (i.e. greate r pedal
pressure requi red).

So now I wonder about the brake light being on only AFTER I left the shop.
 

·
Registered
Joined
·
5,883 Posts
FWIW, the pumps don't fail that often, but the accumulators fail all the time and the ABS light followed in a while by the brake fluid light is typical of accumulator failure. The ABS light comes on because the pump is running too much, or system pressure is low too often, then that is eventually followed by the brake fluid light coming on because the accumulator pressure has dropped below that 105 bar. That's the normal death spiral of the accumulator.

But, there ultimately isn't much value in speculating right now. The first course of action should be to pull the codes from the ABS system and see what it thinks. Then make a battle plan.
 

·
Registered
Joined
·
7,086 Posts
buick regatta and Jag XJ6 sphere's I think are the same. gibe the motor on the side of the ABS a tap, as if that's not pumping you won't get any brakes either, when mine failed as I appraoched a junction I nearly pullled the steering wheel upp as trying to apply so much pressure on the pedal that would budge
 
1 - 10 of 10 Posts
Top