How tough is it to replace rear calipers on a 1990 C900?

It's not bad, but can you define "went out"?

Dave,

Sorry I wasn't more specific. My sister in law had her front brakes replaced at the local midas shop. The front brakes and rotors replaced w/o a hitch, and she was also advised to do the rears as well. When they went to replace them, they told her that both calipers had seized up. There's no brake fluid leaking out or anything like that.. so I'm fairly certain that the brake lines are still good. It seems it was this way since she got the car.. as the rear pads were the originals.(saab original part #'s on them and all). Since they were going to rape her on parts and labor, she opted to drive the car back home and park it... and have me take care of it. This is why I asked how tough it was. She has another car she can drive(the in laws have a few of them) until she's able to get going again.

Anything special I need to know? Do I need to pressure bleed the brakes? etc?

Thanks!

-LC

I've just replaced the rear disks and pads on my car (1983 900S) and once I applied a few simple tricks I'd learnt from others, it wasn't too bad. The first disk took me a few hours but the second one took about an hour. I took the car for a 20 km drive tonight just to make sure things were ok and I got the expected smoking if I braked hard on a long straight where I could build up some speed beforehand.

I was really lucky to get a set of brand new Brembo rear disks at a very low price. Remember that these are solid disks so the process would be a little different with the later C900's (from 1987 up?) with vented disks and handbrakes acting on the rear wheels.

It would not hurt to replace the calipers at the same time as fitting new disks/pads, but I've re-used the existing calipers for the job I did on my car. They come up on Ebay regularly and you can buy rebuilt (or sometimes new) calipers from some of the online Saab parts places. New calipers can be pricey but when it comes to brakes using quality parts is a Good Thing! After all it's the brakes which stop the car, and they're far more important than the engine in terms of your safety.

A pressure bleeder (something like a Gunson Eezibleed which is what I use) makes the job of bleeding a lot easier. Any work which involves interupting the hydraulic circuits make a bleed mandatory, but even if you haven't done any brake work on a car, it's good to do it at least every 2 years. Brake fluid absorbs water so over time it does degrade.

Changing the rear disks/pads is the second major brake project I've undertaken - I did a brake master cylinder replacement on my 1985 900i a while back now and found the Eezibleed very simple to use when it came around to bleeding the old (and horribly contaminated!) fluid from the brake lines. The master cylinder replacement is documented at:

Craig.

Not everyone knows SAAB has this rear brake setup that you have to mechanically back-out the screw which advances the brake pads by the hand brake action in addition to hydraulically pressing the pads by foot action. There is a possibility the your local Midas shop mis-diagnosed the caliper seize up. The calipers may have been good. They just need to be loosened to remove the pads by turning a screw with an allen wrench after removing a cover bolt on the caliper.

It is not possible to remove the rear brake pads without first loosening the screw in each rear caliper. Forcing the pads loose by mechanical means will destroy the caliper.

Midas may not understand Saab's calipers.

So far so good. I agree with that decision.

Well, other than the pads being original (sorry, forgot the mileage if you mentioned it), what makes them and/or you think they'er actually seized? An easy test would be to block one of the front wheels, and then back up each back corner one at a time - spin the wheel, have someone hit the brakes. If the wheel stops, they're not seized. Let's rule out Midas profittering and/or ignorance first.

Maybe nothing. The rear brakes do 10-15% of the work, total. Rear pads can last a very long time without anything at all being wrong. I've never heard of one seizing, so being told that two have seized is suspect to say the least.

Dave Hinz

I believe all c900s have solid rear rotors. The vented discs on the later models were for front wheels only. At least, that is the case on my 1992.

John

I would say get a second opinion. Most brake shops will give you that for free. If your not qualified to diagnose this problem which it sounds to me like your not, then you should not attempt to repair her brakes,nor should she want you to. Brakes are nothing to fool with they have to de done by someone qualified. best regards papa

She bought the car at 83,700 in September last year. I think she's near 90K now. I'll do your test when I see the vehicle this weekend.

Thanks!

-LC

I may not be the most qualified... however I'm also working with second hand information since I haven't gotten to actually see the car yet. Unfortunately, when you work a job that you're on call 24x7, you don't get much time for anything else. I'm going to try the test dave hinz suggested... with turning the wheels and applying the brake to see what happens.

Tack!

-LC

Sounds like a plan. It just seems unlikely that your car would have something unusual happen on not just one, but two corners simultaneously. The simlest explaination is that they're wrong, for one reason or another.

Tell me about it... BTDT, going on 17 years now.

Sounds good. And, I really don't think that working on brakes yourself is a problem, unless you're not comfortable with following procedures carefully. Yeah, they're important, but they're not complicated.