M1114 brake bleeding problem

[motas2002]

Hello everyone, I am hoping someone can provide some insight into the difficultly I am encountering. I am working on a 2005 M1114 with my father. When we received the truck it is in relatively good order. The brakes on the other hand are giving us grief. When you push on the pedal, you get almost no resistance. When we investigated, we discovered that all the bleeder screws where open. We closed them all and then began the process to bleed the system as described in the TM using the correct fluid. No joy. We replaced the master cylinder and repeated the process according to the manual. Still no joy. We tried resetting the check in the proportioning valve and still nothing. We can get small amounts of brake fluid to come out of each bleeder but not that much. The brake petal gains little to no resistance for each of these attempts. Any suggestions? Thanks in advance, John.

 

[CapePrep]

Hello everyone, I am hoping someone can provide some insight into the difficultly I am encountering. I am working on a 2005 M1114 with my father. When we received the truck it is in relatively good order. The brakes on the other hand are giving us grief. When you push on the pedal, you get almost no resistance. When we investigated, we discovered that all the bleeder screws where open. We closed them all and then began the process to bleed the system as described in the TM using the correct fluid. No joy. We replaced the master cylinder and repeated the process according to the manual. Still no joy. We tried resetting the check in the proportioning valve and still nothing. We can get small amounts of brake fluid to come out of each bleeder but not that much. The brake petal gains little to no resistance for each of these attempts. Any suggestions? Thanks in advance, John.

Not sure what the TM says, but most MC need to be bench bled. Might be something to consider.

 

[motas2002]

Not sure what the TM says, but most MC need to be bench bled. Might be something to consider.

Yes, it was bench bleed.

 

[frauhansen]

Most of the time i use a tool like this: https://www.summitracing.com/parts/mva-mv6830 to beed the brakes.
I'm absolutly a fan of this vacuum style brake bleeders. No mor pumping, No destroyed o-rings caus you push the pedal more than it usualy does and you can bleed the brakes as a one-man-job.

But.... i hope you just pushing air around. I had this one time in my HMMWV/H1 times as i changed the main brake pump on a H1. No Pressure at all, even whith the vacuum tool.
I think i solved it by pushing the brake at the same time i keep the vakuum tool on and working.
May this helps!