Rear brakes gone on '71.

[71tahoe]

My son called me last night to let me know the brakes were acting funny and had previously told me they weren't working very well (long stopping distance). I told him it is an old, heavy truck and he should drive accordingly. Last night he found the rear reservoir "bone dry". He was also in a sharing mood a few days ago and told me about locking up the brakes when he almost ran a red light. That could have blown out just about anything in the system but I don't remember seeing any new leaks on the driveway.

I only have Saturday to work on it.

I plan to:
1. Inspect the rear brake hose.
2. Inspect each wheel cylinder.
3. Inspect the MC and add fluid/bleed.

I know I could have multiple problems. Anything else to look out for? I'd really like to get it done Saturday.