Have leaking wheel cylinders. Boo.

Have pile of new parts:
drums
shoes
springs
adjusters
wheel cylinders

Good.

So...how the @$%# do you get the wheel cylinders off? I tried every wrench/socket I have and can't get anything to grip the mounting bolts.

9/32 is too big, 1/4 is too small, 7mm socket kinda-sorta fits but can't turn due to lack of room, 7mm wrench can't grip it either. Bolt itself looks like some type of reverse torx bolt? What black magic did GM use here that my assorted metric and standard tools are of no help?

I've cussed at my Fords and my Subarus for various things...but this is a pain and a half. What am I doing wrong?

Can you take a pic of this bolt?
The only thing Between 1/4 & 9/32..is ..17/64 or 6.5mm or 6.75mm or 7mm... Is the 7mm tight?

I am not sure the size, I think it may be a 9 or a 10, but instead of a T-** you want a socket called an E-**

** denotes whatever size it may actually be, also T= male version of the socket, and E=female version.

This is what the socket looks like.

Yup, it was some type of E series bolt that was pretty seized up.

I finally mumbled, grumbled, and took it to our family mechanic for the install. He has a box of "GM specific" tools. 1 hour and $80 later, he'd done everything and put the old brake shoes in my trunk so I could return them for a core fee.

My parking brake still doesn't work, the cable and spring are frozen and seized from probably never being used by grandma. Can live without it.

Just keep in mind that the parking brake is not just for parking.
It is also known as an emergency brake for a good reason.
If you ever loose you main pedal brakes let say due to a burst brake line....
The emergency brake or e-brake and gearing down..is all you may have left to stop the car.
If ya want you can ask me how I know...Ya it happened to me on the Pk Ave..scarey stuff.

PB Blaster is your friend....