Help with bleeding brakes

[Brocks GN]

I am just about to finish up my vacuum brakes conversion, and was wondering how to bleed brakes? I have never ever bled brakes before so I need some detailed help here. I am all done with bench bleeding the master cylinder, connected it to the car. I know you start with the farthest and work your way to closest, I will have someone heloping me out. I tried a seacrh and did not really find an answer for to my question....TIA

 

[ijames]

My personal favorite is gravity bleeding. Fill the master cylinder, open all four wheel bleeders (about one full turn each), and let it run for an hour or two. Top off mc as needed. You can see bubbles coming out of the bleeders, and they should stop after, oh, I don't know, 5-20 minutes depending on how much air got in the lines. Go a couple of hours to fully flush out all your old brake fluid. I've always gotten a great pedal this way, starting with the stock powermaster and changing both calipers and both wheel cylinders, then changing the mc, then going to the b body front calipers.

The other way is to get a helper in the car, engine not running. Start at the right rear wheel, have him push the pedal down as far as he can and hold it, then you crack the bleeder 1/4-1/2 a turn and let fluid squirt out, then close the bleeder, then have him let the pedal up and push it back down, then you ... You can tell the difference between air and fluid when you crack the bleeder, and go until all the air is gone. Move to the left rear, then right front, then left front. Some guys like to pump the pedal up 5-10 times for each "squirt", but I go with the push pedal slowly once, and lift pedal slowly (2-3 seconds each way) to keep from churning up lots of little air bubbles into the fluid. There is a combination valve on the frame even with the front of the driver's door that sometimes causes problems bleeding the rears, but usually it isn't a problem. If you can't get them to bleed you will need to watch that valve while your friend pushes the pedal. You will see a little plunger come out with each pedal push, and go back in when the pedal goes up. Take a c clamp and use it to keep the plunger from being able to come up.

Whichever way you go, DO NOT LET THE MASTER CYLINDER RUN OUT OF FLUID or you will be starting over and hating life .

They make a cute little wrench for bleeding, but I've always just used a 1/4" drive 5/16" socket and ratchet in the back, and a regular wrench in front (I think 3/8"). Don't touch the paint with brake fluid on your hands, and hose everything off afterwards with lots of water.

 

[Brocks GN]

well i will try the gravity bleed, so you just open up the bleeders and put like a bucket upder the brakes at each whell to catch the fluid and just fill up the MC as time goes on? Seems easy enough! Thanks

 

[zeus87gn]

I recently purchased a small hand vacuum pump that I use to bleed. It sucks all the possible crud out of the system along with the air and the old fluid. Takes less time than the gravity method (which I have never had luck with) and you can do it by yourself if you time it right keeping the fluid bowl full. No worries about the combination valve either.

Only trick with it is to put a small amount of teflon tape on the bleeder screws so you know when you are getting air out. It keeps the air from coming in by the threads of the screw. Also have to make sure you don't put the tape to far down on the screw so it doesn't end up in the cylinder/caliper.

Done about 10 vehicles this way now with perfect results each time.

 

[ijames]

Yes, either a small bowl or a hose going down to a bottle. I know some have had problems with gravity, but when it works it is just too easy . I've also done the mity-vac method, and always seemed to have at least one bleeder that leaked air past the threads no matter what I did (tried both grease and tape on the threads). Definitely faster than gravity when it works, though.