Brake bleeding help

[ldmack3]

Need help on bleeding brakes.
Initially flushed the system when I first got the truck. Got a lot of rusty gunk out at each wheel. Bled successfully.
I replaced the rubber brake lines and bled successfully.
Replaced the master cylinder and rebuilt the airpack and bled successfully.

Then I replaced all wheel cylinders and axle lines and cannot get all the air out. I start with the master then the furthest from the master working closer. The front lines were disconnected for weeks with the front end repairs being done so I bled the crap out of those more times than the others. The other 4 were done one at a time quickly so as not to lose fluid.

I have a sprayer set up to pressurize the system and have run close to 2 gallons of DOT3 bleeding over and over.

I'm going to replace the 5/16” lines when the weather improves and will have to re-bleed them but that won't be until better weather next year.

When I started the pedal went to the floor on first push. Now it goes ½ way, 2nd push ¼ and 3rd about one inch...where it use to be.

I re torqued some seeping T fittings and re-bled. Still has air.
I thought a cracked banjo or fittings, etc but with constant pressure from the sprayer on the system I don't see how air could seep in. Appears air is trapped somewhere, but where?

Ideas/suggestions?

Really starting to PMO!

 

[m715mike]

You said, “I start with the master then the furthest from the master working closer.”

Did you bleed at the airpack first?

 

[INFChief]

You said, “I start with the master then the furthest from the master working closer.”

Did you bleed at the airpack first?

Yep. MC, hydrovac, then farthest wheel away and work towards closest.

 

[Mullaney]

Need help on bleeding brakes.
Initially flushed the system when I first got the truck. Got a lot of rusty gunk out at each wheel. Bled successfully.
I replaced the rubber brake lines and bled successfully.
Replaced the master cylinder and rebuilt the airpack and bled successfully.

Then I replaced all wheel cylinders and axle lines and cannot get all the air out. I start with the master then the furthest from the master working closer. The front lines were disconnected for weeks with the front end repairs being done so I bled the crap out of those more times than the others. The other 4 were done one at a time quickly so as not to lose fluid.

I have a sprayer set up to pressurize the system and have run close to 2 gallons of DOT3 bleeding over and over.

I'm going to replace the 5/16” lines when the weather improves and will have to re-bleed them but that won't be until better weather next year.

When I started the pedal went to the floor on first push. Now it goes ½ way, 2nd push ¼ and 3rd about one inch...where it use to be.

I re torqued some seeping T fittings and re-bled. Still has air.
I thought a cracked banjo or fittings, etc but with constant pressure from the sprayer on the system I don't see how air could seep in. Appears air is trapped somewhere, but where?

Ideas/suggestions?

Really starting to PMO!

.
In a perfect world, there are only two possibilities:

1. You are introducing air through the pressurized bleeder system
2. The first point in the system is sucking air (who knows why) and is pushing it through the system.

If you go to the far end of the system, open the valve until it quits sputtering air, then through the rest working your way to the front, you should NOT get air out of the fartherest point on a second round of bleeding.

Let it sit under pressure overnight. Yeah, if you have a banjo bolt leaking you wasted a gallon of fluid - but that should be really obvious the next morning.

Just trying dumb logic, but it can't be all that difficult. Is it possible that the airpack has the wrong thread type for the bleeder screw that is in that hole?

 

[ldmack3]

.
In a perfect world, there are only two possibilities:

1. You are introducing air through the pressurized bleeder system
2. The first point in the system is sucking air (who knows why) and is pushing it through the system.

If you go to the far end of the system, open the valve until it quits sputtering air, then through the rest working your way to the front, you should NOT get air out of the farthest point on a second round of bleeding.

Let it sit under pressure overnight. Yeah, if you have a banjo bolt leaking you wasted a gallon of fluid - but that should be really obvious the next morning.

Just trying dumb logic, but it can't be all that difficult. Is it possible that the airpack has the wrong thread type for the bleeder screw that is in that hole?

Did not think the pressure bleeder could introduce air but I'll get Mrs. Soldier B to help me. Almost out of fluid again but I'll let it sit and see what leaks.

Negative on the bleeder screw. It hasn't been changed and worked fine before.

Rarely get any air when bleeding now from any fitting. One of the things that's throwing me. No matter how much I bleed it never gets any better.

Update after the snow melts!

Thanks

 

[ldmack3]

You said, “I start with the master then the furthest from the master working closer.”

Did you bleed at the airpack first?

Yep. That's what I mean by master. The fitting is actually in the airpack.

 

[Barrman]

I know you wrote that you are still getting air. However, my thought process went to brake shoe minor and major adjustment because you changed out the wheel cylinders.

Your description of a low firm pedal the first push, then higher and finally firm and high to me read like the air is out and you are just having to push the shoes out to the drum. Read the TM about the procedure. My method is to pick up a side, unbolt the axle shaft or cover in the front, sit under the truck and spin the wheel. Adjust both front and rear bottom adjusters to constant dragging sounds but not dragging the wheel speed. Then do the same on the top adjusters. Repeat on the 5 other brakes and if you had to move any adjuster more than about a quarter turn the pedal will be a lot higher on the first push.

 

[ldmack3]

I know you wrote that you are still getting air. However, my thought process went to brake shoe minor and major adjustment because you changed out the wheel cylinders.

Your description of a low firm pedal the first push, then higher and finally firm and high to me read like the air is out and you are just having to push the shoes out to the drum. Read the TM about the procedure. My method is to pick up a side, unbolt the axle shaft or cover in the front, sit under the truck and spin the wheel. Adjust both front and rear bottom adjusters to constant dragging sounds but not dragging the wheel speed. Then do the same on the top adjusters. Repeat on the 5 other brakes and if you had to move any adjuster more than about a quarter turn the pedal will be a lot higher on the first push.

I do need to go back and readjust. I did all of them with the measurements in the TM. But one of my projects is to pull the wheels and recheck.
Thanks.

 

[INFChief]

Did not think the pressure bleeder could introduce air but I'll get Mrs. Soldier B to help me. Almost out of fluid again but I'll let it sit and see what leaks.

Negative on the bleeder screw. It hasn't been changed and worked fine before.

Rarely get any air when bleeding now from any fitting. One of the things that's throwing me. No matter how much I bleed it never gets any better.

Update after the snow melts!

Thanks

If you’re sure you’ve got all the air out then all that’s left is adjustment.

 

[ldmack3]

I found one brake way out. I have to crank then in to pull the drum by myself and I guess I forgot to adjust this one. Anyway, I cranked it all the way out and the pedal is fine. Waiting for better weather to jack and check the rear 4.

Thanks for all the help!

 

[Mullaney]

I found one brake way out. I have to crank then in to pull the drum by myself and I guess I forgot to adjust this one. Anyway, I cranked it all the way out and the pedal is fine. Waiting for better weather to jack and check the rear 4.

Thanks for all the help!

.
That's always good news!!

Funny how some sort of calamity "at the house or the shop" stops a project, then you have to go back and see where you were. Hate to say that has happened to me before too. The fix for me personally is to leave a wrench hanging on whatever I was working on last... Everybody has their own way but that has helped over the years

 

[ldmack3]

.
That's always good news!!

Funny how some sort of calamity "at the house or the shop" stops a project, then you have to go back and see where you were. Hate to say that has happened to me before too. The fix for me personally is to leave a wrench hanging on whatever I was working on last... Everybody has their own way but that has helped over the years

Yea you know I can even remember giving someone advice to make sure their brakes weren't way out of adjustment. I got so tunneled vision with the line and wheel cylinder R&R I was SURE air was the problem.
Anyway, got the rear 4 adjusted. Pedal feels great. Now if I only had seats and dry roads, I could test them.
I like the idea of hanging a wrench where you left off.
Thanks for the wake-up calls!

 

[cucvmule]

After a few days of travel I bleed again as bubbles still have a way of working out and any dirt, rust in the system gets passed out.
Safe Travels

 

[davidb56]

I found one brake way out. I have to crank then in to pull the drum by myself and I guess I forgot to adjust this one. Anyway, I cranked it all the way out and the pedal is fine. Waiting for better weather to jack and check the rear 4.

Thanks for all the help!

Better weather.........so you're going to do it in the Spring?

 

[ldmack3]

It was warm today, 34, so got the rear 4 done.

 

[Mullaney]

It was warm today, 34, so got the rear 4 done.

.
That seems a little chilly for a hobby repair to me

 

[ldmack3]

.
That seems a little chilly for a hobby repair to me

Yes, it is but I'm tired of waiting, working and spending on it. I want to drive more!!!!
Cold is not as bad as wet and cold. Besides, I'm possessed!