subject is a '97 SAAB 900 SE ("the goose") 4cylinder turbo automatic
171k. Owners for the past 8 years have fixed anything that keeps it from getting to where they're going that day. That's pretty much it.
Brakes developed a spongy feel. Supposedly they have made two attempts to bleed the brakes. The second time the did it with the Key On, Engine Off. No change.
I'll be tackling this problem later today. Wondering if anyone had a super secret SAAB brake repair trick or something.
Not a super secret Saab trick, but... Lines? Calipers / wheel cylinders? Master cylinder? I've tried all of these on a cursed CRX. Unfortunately, NONE of these have fixed the problem... 
But they're all good things to check and/or replace.
belteshazzar wrote: subject is a '97 SAAB 900 SE ("the goose") 4cylinder turbo automatic 171k. Owners for the past 8 years have fixed anything that keeps it from getting to where they're going that day. That's pretty much it. Brakes developed a spongy feel. Supposedly they have made two attempts to bleed the brakes. The second time the did it with the Key On, Engine Off. No change. I'll be tackling this problem later today. Wondering if anyone had a super secret SAAB brake repair trick or something.
Some people say "spongy" when the pedal goes to the floor; others say "spongy" when it's just not as firm as it used to be, but the car still stops OK. which is yours?
if 1, start looking for leaks.
if 2, sounds like a master cylinder going away.
Does it have ABS ? More difficult to bleed .
It's spongy like stepping on a pillow. Car does stop okay-ish.
Just found out they replaced the master cylinder with one from "SAAB-recyclers", which I can only guess means it was used.
I just finished driving around the neighborhood intentionally engaging the ABS. One of my E30's had some air trapped in it once and that seemed to help.
On another note, what the heck is the stupid air-compressor-like sound endlessly coming from just below the climate control system. How irritating.
depends.. I know going from an ng900 to a Classic one had me thinking there was no boost at all on the classic. The classic 900 used a unique boost that makes the pedal feel rock hard and all other cars feel like no brakes at all.
belteshazzar wrote: It's spongy like stepping on a pillow. Car does stop okay-ish. Just found out they replaced the master cylinder with one from "SAAB-recyclers", which I can only guess means it was used. I just finished driving around the neighborhood intentionally engaging the ABS. One of my E30's had some air trapped in it once and that seemed to help. On another note, what the heck is the stupid air-compressor-like sound endlessly coming from just below the climate control system. How irritating.
on some cars, you need to bleed the abs pump/system as well, no? if theres air, it runs the pump constantly or nearly so
If the master cylinder is good, see if you can find a part number on it..and make sure it's the right one. Last time I changed the one on the Golf, they gave me the 22mm bore instead of the 18mm. Screwed up the pressure differential, I've hated the pedal in that car ever since (car still stops OK).
Try http://www.saabnet.com/tsn/bb/NG900/ as well. You don't have to join to search or post.
+1 to master cylinder. I've actually seen it happen when someone thought their brakes could be stiffer, and tried to do the pump and hold bleeding method. The problem with this approach is it makes the seals travel through areas that haven't been touched since the car was new, and all the deposits etc rip up the seals.
UPDATE:
bleeding the brakes did no good.
I bought a reman-master cylinder at NAPA. Bench bled, then bled on the car. All four corners, done in the right order.
Brakes are now firm as hell, but only when you pump the pedal three times. As you're going down the road the first time you use them the pedal goes nearly to the floor and then works well. If you quickly pump them twice after that the travel firms up. Once the vehicle has stopped you can hold the car in place and the pedal does not sink, but instead stays firm at the top. You can then put the car in park, let go of the brakes, and they stay firm. As soon as you start moving though... the excessive pedal travel gradually returns. If you've been rolling for over a minute they're terrible again.
Here's my stab in the dark; I can hear that the front wheel bearings are worn. I'm wondering if the wheel is shifting back and forth as you go down the road, creating more than normal space between the pads and rotors. Is that crazy?
Oh btw, all the lines look good and everything is really dry. I've more or less eliminated the idea of an external leak.
belteshazzar wrote: Here's my stab in the dark; I can hear that the front wheel bearings are worn. I'm wondering if the wheel is shifting back and forth as you go down the road, creating more than normal space between the pads and rotors. Is that crazy?
Ding ding!! You sir have massive pad knock-back from the worn front wheel bearings. I bet the pads are somewhere over 1/2 worn too, yes? Replace the wheel bearings (have fun with that!) and you will have solved your problem.
belteshazzar wrote: UPDATE: Here's my stab in the dark; I can hear that the front wheel bearings are worn. I'm wondering if the wheel is shifting back and forth as you go down the road, creating more than normal space between the pads and rotors. Is that crazy?
Not crazy at all. Logical. I've had some cars in the past that have a spongey pedal due to the pads. Switching to OEM solved the problem. Were the brakes just done?
Pigeon's keyboard prowess is better than mine...
pads are probably somewhere around 70-80 %.
i dunno fellas, i really hate spending money on other people's neglected cars and not fix a problem.
after i returned the car just now, i drove home in my P71, who's brakes felt freaking amazing by comparison. then i started second guessing myself some more....
After switching pads on my RAM, it took a few days for the pedal to return to normal. At first it was very soft but always stopped the truck. I would say you have a winnar.
If you get the brakes working properly then leave it idle in the driveway for 15 minutes and come back, how is the pedal. This will let you know if its motion related.
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