Hi all, I've been lurking around here and finally decided I needed to post. Btw, such a great wealth of information here! Anyway I have a 2000 Jeep Cherokee XJ Sport with 9" drums in the rear. I'm in desperate need of replacing the one of the wheel cylinders. I'm looking around (online/Auto Zone) and noticed there are two sizes for the rear wheel cylinder - 7/8" and a 13/16". Both say they are a direct OE replacement for the 2000 Jeep Cherokees wheel cylinder. Does anyone know which I need, is there a preference, or even a difference?

Thanks much in advance!

Snopes

I think it has to do with which sized drum you have.

You might as well replace both sides or in a week or two you'll be replacing the others anyways! Had that one happen too many times lol

Right, so that's the problem. For the 9" drum i have two options, and that I'm not certain of. Does the 7/8" over the 13/16" bore wheel cylinder make a difference?