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BBBRRRRRTTTTT
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Discussion Starter · #45 ·
havent really solved anything yet.

Ordered a set of brake hoses from PMF, well see if that fixes anything.
 

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Plot twist.. All my issues go away with max ac on.
About the only thing I would think changes is the vacuum pressure. Which could affect the brakes. How that all intertwines would be beyond me without looking at it.
 

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Probably.
Unless I missed it in the thread, you have the factory MC still? Or did you replace Could? Could be internally leaking.
 

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I do. No sign of leakage or fluid loss.
Internal leaks past the cups or O rings won't show outside. The system is still sealed, it's just that the pressure is not maintained on one side. The fluid just leaks around the seal and back to the return port.

 

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I would lean toward Master Cylinder also. The pressure differential can be maintained at a quick, hard braking event, but can bleed by slightly under normal conditions.


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BBBRRRRRTTTTT
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Discussion Starter · #52 ·
started replacing the master cylinder today. not very complicated but a pain in the ***. had to loosed the coolant reservoir which means i had to remove the battery. i also had to remove an ABS module line, that goes to the MC, so i could get it out. that stripped when i was loosening it. so i get to deal with that. the line it self isnt expensive but i hope it didn't mess up the ABS module threads.

any advice or help here is appreciated. or if you know the size of the thread for said hole (its the line on the passenger side of the ABS module that connects to the forward port of the MC - BC3Z2C295A) id like to fix those threads or atleast buy a bolt that matches thread and see if it threads in or not. maybe even tap it.
 

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BBBRRRRRTTTTT
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Discussion Starter · #53 ·
ABS module appears to be OK. Now I just need to replace the bad line and bleed the Jesus out of the brakes.

Any ideas on the best way to bleed this half of the system?
 

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BBBRRRRRTTTTT
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Discussion Starter · #54 ·
New brake line in. Brake peddle firms up easily when the truck is off then goes to the floor with the truck on.

Any tips on bleeding the rest of this air out? I'm assuming the air in the line from the abs module to the master cylinder will work its way out through the master cylinder or should I Crack the lines like you would with a new caliper?

I did let the new line gravity bleed before attaching it but I didn't Crack the other one to gravity bleed.
 

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@TooManyToys can likely give you the correct answer, but as for me personally, I would bleed the whole system.


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BBBRRRRRTTTTT
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Discussion Starter · #57 ·
I was planning on the whole system just didn't know if there was a way to get it out before it goes through the whole system.

How do you do it electronically? I've never been able to find a procedure or anything. I have forscan.
 

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You are past the point where you could try to get the air out of the lines before it got to the ABS module.

You need IDS, Forscan, or one of the other service tools. There is a procedure for the pump and valve to operate while you bleed at the wheels.

When we had a prototype ABS system that did not have corresponding electronic programming for bleeding, we would spend all day stopping on gravel to actuate the ABS, then manually bleed. Over and over. A good day was four hours of doing that.
 
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