The Stovebolt Site Forums The Shop Area Driveline Brake line bleeding

I replaced my brake system lines and all. I bench bled the new dual master cylinder. And in the process of bleeding the lines I have put 2 quarts of fluid in. One full quart has gone all the way through into the catch bottle but I am still getting air. Does it ever end?? I have never done a full system before. How much fluid is normally required to purge all the air from a system??
Thanks.

Hy Rustyoldtruck, I assume you're bleeding them with the pedal, don't have your bleed screws too loose or they can suck air into the system on the upstroke of the pedal, or you can open and close them with every stroke of the pedal, hope that helps.

I have a helper working the brake pedal. I am opening and then closing the bleeder screw before the pressure fades.

Hy Rustyoldtruck, Are you getting air out of both systems, or just one? Did you bleed the primary system first?

Adjust all of your shoes out tight to the drums so you know that all the air is bled out, the back them off to the proper clearance. If you have Huck brakes, this requires adjusting both front and rear shoes at each wheel. Sometimes when adapting new parts to the truck, you need to adjust the pedal rod adjustment too,
Scott

One thing you might check is that all of the fittings are tight. It's easy to miss one. I had to finish a job last week that a co-worker (with 25 yrs. experience) who had replaced a line from the front to the rear on a late model C1500. He couldn't get it bled, ran at least a quart or better through they system. Well, he was off the next day so I had to finish it. Now, i didn't check it myself, so we just bled it. Kept getting air and no pedal. Had my "helper" (the new guy :rolleyes: ) get out and proceded to lift the truck to investigate. Then I saw the drip. The front fitting was loose!! Tightened it up, bled it out, everyting was fine after.
So don't feel bad if one is loose, it even happens to the pros!

I had 3 leaks yesterday when I first started I got them all fixed. The quart of fluid I have run through the system has been since I fixed the leaks.
So that is my question is it normal to run this much fluid through a new system or do I have a problem somewhere?

3B
I am still working on the first wheel the one farthest from the master. I have understood that you must get the air out of the line at the farthest point first then work your way toward the master.

Hy rustyoldtruck, I have allways bled the primary system first [the one closest to the brake pedal], I have also used the primary system to activate the largest brakes, on a half ton it doesn't make much difference. After the primary is bled you can turn your attention to the secondary, once the primary is bled it will shorten your pedal stroke considerably, what I have done with success in the past is to leave the last bled primary bleed screw a little loose and immerse the bleed hose in a jar/bottle with a little fluid in the bottom, this will allow you to get a better bleed stroke with the secondary system. Keep checking your master cylinder level and the level in the primary system bleed jar/bottle, hope that helps.

Rusty,
if you have not progressed past the one wheel, you will not have a solid pedal. You shouldn't need to put a quart through at all. Initially you should see the air spurt out and then there is just fluid.

If the master cylinder is the type which requires separate residule valves and none were installed, the wheel cylinders will always draw air in.

if you use a clear 1/4'' tube slipped over the bleeder nipple into a clean soda pop bottle you can re-coop your fluid. this also helps so when you pump or close the bleeder screw w/ the tube still immersed in the bottle fluid, air can not be drawn back into the line anywhere. one qt. should have been plenty. use flare wrenches to tighten ALL your connections, AGAIN.
start with the farthest brake line and work back to the shortest line.
I used this process and it took about 1 hour to completely bleed my all new everything, master to all new wheel cylinders & disc brakes up front.

You could also go with speedbleeders.
They are cheap and you can bleed the brakes yourself with zero hassles in no time.
I used to do it the traditional way for over a decade but am glad I found a quicker, easier way which gives me better brakes as well.

is it only one wheel cylinder?
I have had in the past, a wheel cylinder piston seal that won't leak fluid but will suck air back when the pedal is released causing a progressively low pedal as more air leaks back in, the piston was sticky....hope this helps

I just finished fabricating a whole new brake system using a dual master cylinder on my 51. I made new lines as well. I found starting from the furthest wheel and working your way back works best.
I also made up a power bleeder from a plastic bug sprayer bottle from Lowes for 10 bucks. This greatly speeds up the process and put the fun back into working on the brakes.

Thank you all for your replys and suggestions. I have been short on time but am still working through it.

Well I got back to working on the truck yesterday.
I took out the offending cylinder and took it back it was a Chinese made part from Autozone. I then went across the street to Checker auto and bought an American made cylinder. Got home put it on and had solid pedal after only 3 pump and bleed routines. So I guess it was just another example of Chinese made crap that almost works. Lesson learned buy American .....