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.

[lukecp]

Easiest thing to do would be to put some fluid in the reservoir, have your son press the pedal down, and look for leaks. I helped a friend with the same thing on a Ford Ranger a few weeks ago, and we found the problem really easy when we heard it literally spraying fluid from a rusted hole in the rear brake line. The truck had sat for a few days and there weren't any puddles or drips underneath it until we filled the reservoir and pushed the pedal.

I'd be betting on the rear brake hose myself, but inspect all of the lines, including the hard lines. Best way would be to fill it up, press the pedal, and look for leaks.

[71tahoe]

I like me pumping the brakes while he crawls under the truck.

He doesn't like the truck being "grounded" until Saturday but he did agree to look today for anything obvious. The last rear brake hose I replaced had to be cut off by the frame. It was a real pain working in such a small space.

[Green Machine]

Master cylinders tend to leak out the back, and I assume your 71 has power disks. Might want to loosen the MC and move it away from the booster a little and see if there is fluid between them. Wheel cylinders are highly suspect, they usually leak slowly, check the brake lines, they usually would have a big leak easy to spot.

[nplocoman]

Could be the MC. If the wheels look dry, check under the floor mat near the steering column where the MC push rod goes through the dash. The fluid could be coming from the rear of the MC into the cab.

[71tahoe]

Thanks. I've had the truck over 17 years and never replaced any hydraulic parts. It's probably time for it to go. Plus my 17 y.o. is driving it. He's got to go fast before he has to slow down. It's only fitting we replaced the clutch (or the 25+ pieces that once resembled a clutch)about 3 weeks ago.