Bleeding brakes. LBZ dually

Ron2145

Member
May 6, 2016
83
2
8
Whitefish, MT
Hello, I have bled the brakes myself several times over the years when I have done a brake job on this truck. For some reason this time it’s not working. I have been doing it by myself with the bottle and tubing. Maybe I need to do it old school.

Is it possible to clear them out without a computer to purge the anti-lock module? I have clean fluid at all the wheels now.

Thank you!


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TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
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Mid Michigan
What do you mean, "its not working"? Pedal still spongy or drops to the floor? Locked up brakes?
 

Ron2145

Member
May 6, 2016
83
2
8
Whitefish, MT
Pedal goes to the floor. So it has to be air in the lines? I’m not getting brake fluid on the ground. I re-bled it all today. So it may be time to get some help pumping the pedal. My main concern is if I managed to get air in the module can I get it out or will I need to take it to a shop.


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Last edited:

Ron2145

Member
May 6, 2016
83
2
8
Whitefish, MT
Ok. Thank you both for the responses!There’s a tool that mounts on the reservoir for that, I believe. I will check into it.


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Ron2145

Member
May 6, 2016
83
2
8
Whitefish, MT
So I got a vacuum bleeder and re-bled them. Starting from furthest to closest. I didn’t see any air. Peddle doesn’t build up pressure, I started to think I blew the seals in the Master Cylinder, there wasn’t fluid between it and the hydro-boost, but I put a new one in anyways because it’s never been replaced yet. Bench bled it and then bled it at the master cylinder. Still won’t build pressure. There’s a little resistance but the pedal just goes down, it’s like a bleeder is cracked but I’m not getting fluid anywhere. I’m stumped, can it be the ABS system, I don’t know if it has some kind of bypass. Any thoughts appreciated as always!


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TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
16,916
3,421
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Mid Michigan
Sounds like air in the ABS module thats not coming out. Going to need a scanner that can run an ABS bleed to find out, though.
 

Ron2145

Member
May 6, 2016
83
2
8
Whitefish, MT
Well, I had a dumbass moment, I didn’t catch the calipers were in the wrong box and they were upside down! I kept looking at the bleed screw thinking it didn’t make sense, but I put them on based on the label. So, after I fixed that, things are much better, it builds pressure while off, but I think I did get air in the ABS when I changed the Master Cylinder. Are the Icon scanners from Harbor Freight any good? For what they cost, it’s probably a wash versus having it towed to a shop. It looks like the T-7 and T-8 have the bleed function.


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