OK, finally was able to get the brake drum off the rears and replace the shoes, springs, etc. I also replace the wheel cylinders on both left and right sides. After bleeding the right cylinder, the piston extends way out and starts leaking.
Is this a defect?

At first I thought it is, it is..but then I thought, with the drum on there is no way the piston should come out that far. I'm not really wanting to take it all apart to remove and return the brake cylinder, but will if I have to. I'm thinking of throwing the drum on and then test driving it a bit and see if it still leaks.

Do you think this cylinder is defective?
Any thoughts?

 

Maybe you installed the rear brakes incorrectly. Compare with the other side and post some pictures.

 

This is one of those things that should not happen. Also make sure you have the correct drums. The shoes should fit closely in the drums (same diameter).