Bleeding brakes question 79
Thread Starter
Burning Brakes
Joined: Oct 2013
Posts: 992
Likes: 28
From: Sutton MA
Bleeding brakes question 79
When we bought our car we had to limp it home, was for sale right up the street. I noticed the back brakes were soft, checked the master cylinder and it was dry only in the rear chamber, actually I filled it up before we moved it.. The car sat for 4 years that I know of. Anyway I replaced the leaky caliper and while I was trying to get it off the chamber drained completely again. Now that it's replaced, I'm attempting to bleed the caliper with a vacuum pump. I've spent a couple hours and still seem to be pulling more air than fluid . Is there something I'm doing wrong here? Was it because the rear chamber completely drained? And even though the leak was on the passenger caliper and that was the only break in the line, do I have bleed both rear calipers before I see a good steady flow at the right rear?
Melting Slicks
Joined: Mar 2009
Posts: 3,126
Likes: 15
You may be pulling air past the threads of the bleeder screw. On an otherwise healthy C3 brake system you should be able to gravity bleed the brakes. I raise the car and place it level on stands. Remove two F/R or all four tires. Open all bleeders with MC cap off and let nature take it's course. Refill MC as fluid drains. It took about two hours for my completely dry system to show fluid at the rear. I use DOT5 silicone so no worry about paint damage from the fluid. Place some clear tubing on the ends of the bleeders and down into a catch can to keep control of the DOT3 fluid as it is a very effective paint remover. Good luck with it. mike...
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
I have tried all kinds of ways bleeding them. Vacuum, gravity and pressure. I have found pressure through the MC to work the best. I used a Motive pressure bleeder and it worked well. I now made my own plate that clamps to the MC and pressure the MC with my compressor. 10 pounds works very well. Never had another issue bleeding brakes. They come out rock solid every time.
1st Gear
Joined: May 2014
Posts: 1
Likes: 0
From: Brownsburg IN
I just purchase a '79 and the rear chamber of the MC was also empty. I capped the output port for that chamber and pumped the brakes to bleed the MC. Then reattached the line and bled the rear brakes the old fashioned way. Son pumping the brakes, with clear hose on the bleeder. With dry lines it took a bit of pumping to get things going but worked pretty well. Kids are excited about the car now since it is new and want to help. I'm sure that will change and I'll have to figure out a 1-man way of doing it soon.
