FCA 2016 ABS process

[tshephard]

Prepping for fluid flush, lines, pads for a 16 Challenger base.
I see a lot traffic about ABS flush procedure.
So I have a couple of questions!

1st - Why raise rear of car?
(This car has a far front mounted pump/valve assembly, and I suspect 'raise rear' is really a way to lower front assembly to increase odds no air gets into assembly, in case of underfill error.)

2nd - Not gonna' risk dealer, etc. - so how to flush ABS assembly?
I will also suspect Key On will cause cycling, and that fluid moved from assembly needs somewhere to go.
So maybe:
Ensure fresh fluid in lines approaching assembly (by normal flushing).
Open a bleeder.
Key On/ Off, maybe 5 times? (Moves assembly circuit fluid into line)
Normal bleeding on that corner and see some dirty come out?
Any help?

 

[atikovi]

ABS does a self test when you hit 3-5 mph. Key On/ Off probably won't do anything. Without a scan tool to activate the ABS properly, you will still get 90-95% of the old fluid out, which is good enough.

 

[tshephard]

Now we got something!
Maybe in the air carefully, car senses MPH, cycles, squirts?
Sound close?
2nd thought, bottle, hose attached, short driveway crawl for MPH...
THX!

 

[ctechbob]

I've been under the impression for many years now that most modern ABS systems do not hold any fluid in reserve like some of the first-gen systems did, so special procedures aren't really necessary. Bleed as usual and done.

 

[tshephard]

I've been under the impression for many years now that most modern ABS systems do not hold any fluid in reserve like some of the first-gen systems did, so special procedures aren't really necessary. Bleed as usual and done.

The way this device looks they clearly have minimized size, so passages appear to be minimal, etc. Volume is probably actually very little.
I'm balancing that against what I read about fluids blending, lets say traveling in a sealed tubing system despite my 'common sense' that the fluids just move a hair back and forth. It seems that water/dirt/dilution whatever will spread thoroughly in a system.
Trying real hard to figure/find the best way to do it myself.

 

[MattPersman]

You could power the pump on. Not sure what the reasoning for less than 1% of the fluid capacity that’s in the HCU

 

[meep]

7mph was the magic number where all the things used to happen pre-fiat; idk about now. The abs module is simply a pump and 3-4 solenoid valves in small passages. It’s going to naturally exchange fluid with its surroundings as its used. Unless you have a fluid problem, I would not even pause for concern. Bleed the normal way and move on. Keep in mind that all of the braking goes through it anyway, so half of its circuits will be changed by the bleed as-is.