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Discussion Starter · #1 · (Edited)
I have looked at a few threads and may have an idea of whats wrong.

Both ABS and Brake fluid light is on.
Stiff Brakes, Less then half the normal travel distance.
Stiff even when car is first started.
ABS Hydraulic Brake Actuator Unit?? or?

If so is it still safe to drive the car a short distance??
 

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I have looked at a few threads and may have an idea of whats wrong.

Both ABS and Brake fluid light is on.
Stiff Brakes, Less then half the normal travel distance.
Stiff even when car is first started.
ABS Hydraulic Brake Actuator Unit?? or?

If so is it still safe to drive the car a short distance??
It may be the accumulator, otherwise known as the "brake bomb". It is the black sphere next the master cylinder. Do a search here using those terms. As far as driving, there is no assist and ABS will not be working.
 

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Discussion Starter · #3 ·
Shouldnt there be some pressure at all even without the accumulator not working, shouldnt the pump still make some pressure for the brakes?
 

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Shouldnt there be some pressure at all even without the accumulator not working, shouldnt the pump still make some pressure for the brakes?
I'm not an expert, but I don't think so. The accumulator has a diaphragm inside that has some sort of gas on one side, and brake fluid on the other. When it is pumped up, the gas compresses and pressurizes the fluid. When the bomb is bad, the diaphragm is broken and more brake fluid goes into the sphere, but there isn't anything in there to compress. Hence the hard pedal.
 

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Discussion Starter · #5 ·
I read the failure test for the accumulator. Shouldnt the pump still run and try and pump up the accumulator. Both lights are on all the time, even when the car is first started. The pump never tryings filling the accumulator.
 

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I read the failure test for the accumulator. Shouldnt the pump still run and try and pump up the accumulator. Both lights are on all the time, even when the car is first started. The pump never tryings filling the accumulator.
Maybe the pump is not getting turned on.

Sure it is safe to drive a short distance carefully but not daily driving.
 

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Discussion Starter · #7 ·
Could I just remove the ABS? Or do I need other things to replace it like a brake booster?
 

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Could I just remove the ABS? Or do I need other things to replace it like a brake booster?
This is a big PITA and fixing it correctly is only a little PITA :p

It doesn't sound like there is any problem with the ABS rather a problem with the pump or accumulator, it is probably a little switch :lol:
 

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You should be able to hear the brake pump running when it's building up the pressure in the brakes. It turns off 10-15 seconds or so after startup. If you pump the brakes rapidly, it will come back on. If you don't hear it at all, you need to troubleshoot the pump and switches.

The pump should be able to pressurize the system even if the accumulator is bad. The system won't have any reserve in it. This means the lights should go out once the system pressurizes but come on within the first couple of presses of the brake pedal.

I've never serviced the ABS other than to change out the accumulator so there may be other problems I've not experienced going on here.
 

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Check brake fuses and relays - dedicated relay/fuses box at right front wheel fender.

Use voltmeter and check electricity here.
Check volts at connector of ABS pump - left front side of main cylinder unit, two thick wires (left side of picture, could be partially seen under reseivoir).

These tests should you say, if there is problem with power or with pump itself.
Anyway, it looks like pump problem, not ABS. Pump/brake power is above ABS function, so when you rectify this one, ABS light should go off too
 

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wife's vert had similar prob I had a spare abs 'unit' so did complete replacement, but it was the pump, it worked when turned on but then did'nt recharge only occasionally so sometime you had brakes sometimes 'hard' brakes and occasionally felt like you wer'nt going to stop at all as went soft. someone on here a few weeks back had abs prob and they founf if they tapped pump with hammer it would run ...which baically meant the pump motor was had it (bit like starter motor etc sticking), putting a std sercvo in it's place would take some work, and certainly not worth the effort,cost..... repair the abs
 

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Discussion Starter · #14 ·
Well I took off the relay and gave direct power to the pump and the pump worked. Hooked up the relay and it was giving low voltage and sometimes nothing. Sometimes the pump would turn on when I wiggled it. It would then heat up and cut power to the pump. So I ordered a new relay and hopefully that was all that was wrong.

Also my crank sensor recently went and I wired up a turbo dizzy and it fixed the problem. The vacuum advance unit doesn't work on the dizzy tho. Would this one work?

http://www.thesaabsite.com/shop/sea...cuum+advance&myCat1=900+79-94&a1=Start+Search

Also I did turbo my car and I haven't touched the timing so I was thinking this may help. Unless there is somewhere else I can get one?
 
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