'89 900 (non-turbo) Rear Caliper Piston Question

Being a 1989 car it's got handbrake-rear calipers presumably... I've noticed when replacing pads on my handbrake-front C900's that as well as winding in the piston the yoke itself sometimes needs to be moved as well to give enough clearance either side of the rotor to fit in the new pads.

The process might be different for the 1988+ calipers though.

Craig.

I found out that what needs to be done sometimes is you need to use a C-clamp to help push the piston back especially when it gets to be almost fully retracted. Also, some brands of brake pads are too thick so they must be sanded down (with an electric sander) until they fit. It can be very frustrating trying to rebuild old calipers so anyone who wants to do it better have patience and an alternate vehicle to get the extra parts that you'll most likely need otherwise get new or professionally rebuilt calipers.

I don't know what material it is, but I sure wouldn't want to breathe the brake dust. Maybe a milling machine with carbide tooling. I'll try it & see how it goes.

Yes. For the 50 bucks or so of rebuilt caliper cost, the time/cost/hassle just doesn't work out for rebuilding yourself. At least not for me. There's fun work on cars, and that isn't it.

oh my god NO NO NO NO NO!!!!!!

There is an adjuster for the rear parking brake. As the pads wear, the piston will be adjusted more outward to keep the parking brake working properly.

When replacing the rear pads, take off the 14mm plug on the rear of the caliper. Inside there is a 4mm allen screw. Loosen the screw and you will see the piston retract into the caliper, or it will go with a light push (assuming it isn't seized).

RTFM!

oh my god NO NO NO NO NO!!!!!!

There is an adjuster for the rear parking brake. As the pads wear, the piston will be adjusted more outward to keep the parking brake working properly.

When replacing the rear pads, take off the 14mm plug on the rear of the caliper. Inside there is a 4mm allen screw. Loosen the screw and you will see the piston retract into the caliper, or it will go with a light push (assuming it isn't seized).

RTFM!

When the caliper piston is as retracted back as far as it will go by using just the allen/hex screw adjuster then some gentle 'coaxing' with a C-clamp is needed to help push it back just a millimeter or so further (nothing forceful). After doing that then you again adjust the allen screw to 'take up the slack'. You may need to use the C-clamp again and don't forget to follow it up by using the allen wrench. This advice was told to me by a Saab mechanic and it worked out good for me. Just remember never to force it and be patient. I once again advise to not do this cailper rebuild if you get easily frustrated because Murphey's Law will definitely be a reality. Luckily I had a parts car ('87 9000) which I used a rear caliper from because on one of the 900 calipers I could not get the adjuster plug/screw (to access the piston adjuster) loose because it was so rusted that it had become fused to the caliper body. Unlike the other rear caliper this particluar 'adjuster access screw' was also an allen type so it was very difficult to try to remove it because the allen wrench (when compared to a socket or wrench) is so thin that it just bent under the stress of trying to torque it loose.