Actually, in that picture the accumulator piston should have popped out, but you can tell its stuck in there.

haha, a couple swift wacks with a screwdriver and it popped right out and now moves freely.

So I now have a spare master cylinder and hydroboost off of a 2005 2500hd if anyone wants to buy one.

I am pretty confident that was the problem, but I have to install it back first...(knock on wood).

 

Yep, works great, I can lock up the tires at any speed below 60 now, and thats saying something for 35" 115 pound tires.

And to think I spent 3 days trying to figure this out when all it needed was to be hit a couple times.

 

Bfh ftw!

 

I'm reading this after I read and reread your install writeup last night. Nice job. I'm thinking of doing this myself, got a killer wrecking yard 15 minutes down a gravel road from me. But that broken bore isn't buggering anything up? That'd scare the crap out of me to find something like that.

 

Nah it wasnt broken, it was just jammed in there. Im thinking whoever took it out of the wrecked tahoe dropped it on the rod and jammed it in there. Works perfectly fine, truck stops great.