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hey all! so I'm completely new to forums in total, let alone a saab forum so this is my first post. my saab 900 is my first car and i am a total do-it-himselfer! I am stuck with antilock problems. basically my antilock warning lamp remains lit when driving and whenever i apply my brakes semi-hard, my brake fluid level warning lamp flashes-then goes back off. I tested impedence from all four speed sensors and got good values for all except front drivers side where i got nothing. then i took off wheel and found that sensor wire (which is dual axiom) is frayed right near sensor housing and i did a good solder job to avoid buying new. i then got good impedence! my light went off for a short test drive then i drove it later that day and it came back on and stayed on =(. now (few weeks later) i measured each sensor again and im getting about 750 ohms for all (the range is supposed to be 800 to 1400 when wheel not rotating). also, i just tested my brake fluid level sensor and got 1 ohm at contacts 3 and 4 but did not get the 10 at 1 and 2. does anyone have any suggestions so that i can fix this without having to involve a mechanic?? is 750, while outside the range, the real fault issue or not? is my fluid level light and antilock light related, or is the fluid level light just because of the apparently faulty level sensor? note: im not loosing any brake fluid from the reservior and never have. please help with what you can!! thanks! note: accumulator buzzes upon turn of ignition, i dont think its an accumulator/abs unit fault
 

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How many brake pumps does it take to set off the lights? How long does it take for them to go out when you start the car? After you set off the lights? Your fluid light has nothing to do with the impedance of your ABS sensors, so I think you have a broken accumulator diaphragm.
The buzzing you're hearing is your ABS pump working to pressurize your accumulator. Your accumulator itself should not be making any noise, if it is, it is leaking! Try this test:
Stomp quickly and repeatedly on the brake pedal and count the number of applications until the lights come on. Less than 5 - broken accumulator. 5-10, its about to go.
I get 14 on my new one. Had the same symptoms as you before I swapped mine.
Luckily if it is this, there's a GM part number that costs 1/3 of OEM SAAB.
Can't think of it right now but search is your friend. Good luck.
 

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hey all! so I'm completely new to forums in total, let alone a saab forum so this is my first post. my saab 900 is my first car and i am a total do-it-himselfer! I am stuck with antilock problems. basically my antilock warning lamp remains lit when driving and whenever i apply my brakes semi-hard, my brake fluid level warning lamp flashes-then goes back off. I tested impedence from all four speed sensors and got good values for all except front drivers side where i got nothing. then i took off wheel and found that sensor wire (which is dual axiom) is frayed right near sensor housing and i did a good solder job to avoid buying new. i then got good impedence! my light went off for a short test drive then i drove it later that day and it came back on and stayed on =(. now (few weeks later) i measured each sensor again and im getting about 750 ohms for all (the range is supposed to be 800 to 1400 when wheel not rotating). also, i just tested my brake fluid level sensor and got 1 ohm at contacts 3 and 4 but did not get the 10 at 1 and 2. does anyone have any suggestions so that i can fix this without having to involve a mechanic?? is 750, while outside the range, the real fault issue or not? is my fluid level light and antilock light related, or is the fluid level light just because of the apparently faulty level sensor? note: im not loosing any brake fluid from the reservior and never have. please help with what you can!! thanks! note: accumulator buzzes upon turn of ignition, i dont think its an accumulator/abs unit fault
If I remember correctly, ABS light on is an electrical fault, fluid light on is a pressure problem. One can affect the other.
750 should be ok.
If the ABS light comes on when you start moving there's a good chance it's wheel sensor fault.
 

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Discussion Starter #6
yes i noticed just that! pretty much i start moving and especially when i turn the wheel the light comes on and stays on ( and this makes sense to me especially because i inspected the front wheel sensors at there housing and the design to have the sensors wire bend so much especially at wheel turn has, over 19 years, cracked the insulation to the wire). Also when i described the fact that i had good impedance values and then a few weeks later all 750, the latest measurements i made with my multimeter which is old and not digital and maybe is not good! and the old measurements i made with my freinds DMM. but what is for sure is the drivers side front wheel speed s def had a reading of 0 and then i soldered the **** out of it (neatly) and protected it with hosing and clamps and it then read the right value! but like i said lights just came back on eventuall! i am going to go out and buy a dmm and then retest! also thank you Max Blast I am going to try those test like you say!! although right now its almost 5 in the moring and if i go to the garage to try anything with my saab my dad will kill me! thanks all will repost soon with report. happy saabing!!
 

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Discussion Starter #7
update: so when i turn the key but dont start the car and its sitting there ready, i hear the buzzing of the abs pressurizing the accumulator. after that i press only one time on the break and both fluid level and antilock light flash on and i hear another shhort period of buzzing! this is broken accumulator diaphram correct, cuz i can keep the pressure?? if so do i need to buy and install a whole new accumulator? and is this hard and is there directions to do so? i believe bentley doesnt say how because they want abs problems to be taken care of by the usual "authorized saab mechnic" . thanks for any and all help!!! happy saabing
 

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It's dirt simple: remove the old accumulator. CAREFULLY pry off the small appendage on the end of it. Pry off the similar looking one on the new Buick one and swap them. This is your metering valve. Use a soft mallet or a piece of wood to tap the old metering valve into the new acumulator. Install the new accumulator. Ensure your brake fluid reservoir is at full. Turn the key and wait until the ABS pump fills the new accumulator. Top off the fluid level.
Enjoy brakes that work without lighting up the dashboard.

Lucky for you, this is about the easiest thing to repair on an ABS brake system. When the accumulator breaks, the diaphragm inside has ruptured. In A working one nitrogen gas is excerting pressure on this diaphragm, which in turn exerts pressure on the brake fluid even when the ABS pump is not pressurizing the system. This is what an accumulator does. If the diaphragm is ruptured, the pump only fills the accumulator with brake fluid, but as we know this is not compressible an you will not have any pressure in the system until the ABS pump restores it. Driving around with a broken accumulator is a great way to prematurely burn out an ABS pump. Get a SAAB or Haynes manual. As you can see, this is not rocket surgery.
 

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Discussion Starter #9
it def sounds simple! does anyone know where i can go online or elsewhere to get the buick one and what model number it is or anything? thanks!
 

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Apologies, don't mean to hijack this thread but have searched and not found a similar issue (and respondents here very knowledgeable).

1992 900S
ABS working fine - warning light extinguishes as it should after start up.
On holiday in London so had all the 'boots' changed on the car including steering.
After 30 miles or so in London - ABS light came on.
ABS light stayed on.
London Saab Garage who did boots checked sensors with DMM; OS sensor reading too low on FOS sensor.
Cleaned sensor.
DMM reading now ok (fluctuation between 0.1 and 0.3 when wheel turned).
ECU reset.
Driving back up North immediately after garage 'sensor cleaning' - ABS warning light on after 30 miles. Drives as it should but ABS warning light stays on from ignition.

What should I do next? (taking it back to garage not an option in the short-term).
Thanks
Ez
 

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Strangely enough, I have 2 Buick Reatta's as well as a 1990 900 Turbo. I had the entire ABS system replaced on one of my Reatta's for $1000 with used parts. Works fine now. A new Teves ABS system is $1600 alone(not including about 1 day of labor), including the ATE accumulator.

Is the ABS system for the Saab 900 also made by Teves?
 

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Discussion Starter #13
thank you all very much for the help so far! the tip on the buick accumulators was such a savor!! (huge mishap with gm however, two sets of cards information wouldnt go through on there end for payment and my accumulator was over a week late to get to me despite my paying for two day rush!!!:x:nono;) anyway brake fuid light problem fixed! now only my abs light comes on! never thought id be excited about that! just wanted to give the update-im betting anything its a sensor or two (or mebe 3 or 4 ? god help me) and im buying a reliable dmm to test for that. each sensor is $100 though - im afraid to even test them :roll: happy saabing!
 

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not sure if any difference in length but rh side fits lh side front and back and if same wire length you only buy one and swap it over, but if a multimeter is used you can tell if 1 has gone, so no need to buy until fault found, so $100 they are £95 in Uk but that's a lot more in $, fortunately when I broke a 900 I kept them all, so saved £96 on last uk MOT test as one failed:cheesy:
 

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ABS query; the fault codes have been read and the fault is the right hand front sensor - no signal being received. Can I just check this is the driver's side in a uk car?
Ta
E
 

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Have you down loaded the fault codes from the ABS control unit?
On my 92 convert the unit is under the rear seat to the right.
There is a 2 connection plug laying unpluged right next to the big plug on the control unit.
There is a way to connect these together and read flash codes from the ABS lamp in the inst. cluster.
Last time I did it I did it wrong and the ABS went bad and lost all brake boost.
Luckly it came out of it the next day.
Surely some one here on this board can fill you in on correct method and list of codes/number of flashes.
You might find the problem from the flash code info.
TrollMedic
 
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