His 01 1500 4x4 has lost it's brakes and it won't go into gear. Are these related? He has replaced lines and hoses and has peddle when sitting but looses it when started. Could this be related to ABS? Maybe a bad master cylinder?

Can't see them related. Did this happen at the same time? First "won't go in gear" I assume you have a automatic. Fluid level,linkage problem? Brakes "looses it" pedal goes right to the floor?

He bought this truck for his son to fix up. Yes, auto. It starts fine and runs good. It had bad brake lines so he replaced those with plans of loading it onto his trailer. I think he has a bad master cyl. That doesn't explain the not going into gear. He is thinking it's ABS related. I don't have a clue. Probably unrelated except for neglect.

won't go into gear as in: gear shift won't move? or gear shift moves, but trans does nothing? We've got to "assume" it's the second choice here, and if so, I'd suspect a bad pump.

T case in neutral?

As to the last two posts, I don't know. It's my friends truck and all my info is second person. I know he dropped the drive shaft to get it loaded. Sorry, wish I had better info for you guys. I was hoping it might ring a bell with somebody, that's all.