Hi all, the car in question here is a 93 944T, my girlfriend's car. ABS, no IRS. The left rear caliper has a seized piston, and I want to get a rebuilt unit.

The calipers on the car have no clear markings. There is a 3, but nothing after that. I measured the pistons to be 34mm diameter. This was the exposed portion of the piston. I don't know if it has a greater diameter where it goes into the bore. The pistons have straight sides, right?

I called up Autozone and they asked me if they were 38 or 40mm pistons.

The IPD catalog shows a 34mm piston for 760, but only up to 92. They don't even list any rear calipers for the 940. RPR shows just one part for the 93 940, but they don't say what diameter it is.

What is it supposed to be??? I searched the archives and I found 2 other posts that asked similar questions, but neither one had any replies. I hope this one doesn't get the same fate!

Thanks for any help!
Greg Wong

Greg-
I will be replacing both the rear calipers on my 945t tomorrow; here is what I found. The responses that I got told me that all 940 turbo wagons had 40mm pistons. Now when I measured mine, I too got 34mm for the exposed portion of the piston. I BELIEVE that the sedans came with 38mm pistons. Now, this may not sound like much help, but what I know for a fact is that regardless of what size piston you actually have, if you replace BOTH calipers with the same size piston you will be fine. Check the other one, it turned out that both calipers on my car were faulty. Hope this helps.

Jason

Thanks, that does help. That's interesting that you measured the exposed part at 34mm also. I think you might be right about the sedans having 38mm pistons.

Thanks again!
Greg