Master cylinder replacement and brake bleeding hasn't fixed a soft brake pedal

[JayOh]

Found few links that suggested trying to extend the rod from the brake booster a bit further - will see if this is possible.

[TR Laredo]

Have you checked the flexible rubber hoses to see if any of those are ballooning out when under system pressure?

[RLT]

What front brake hoses do you have ?
Mopar ones were changed from a shorter more direct type on the 2007 -2010 production to a longer one that has a bit more of a convoluted pathway to the calliper from 2011.
https://jeepey.com/product/brake-hos...nt-68171944ad/

I found this out when I had to change the front callipers out, that the dealers couldn't supply the earlier type of hose.
Wasn't absolutely sure that the new longer ones would work with my AEV 2.5" lift & brake extensions, so bought some Crown front hoses suitable for my 2007 to keep it the same.
https://jeepey.com/product/brake-hos...ft-52060045ae/

So just wondering if your JK has a manufacturing date prior to 2011 and has had the hoses changed out since then to the longer type if that might make a difference ?
It maybe clutching at straws but you seemed to have tried everything else !
Please keep us updated if you get it sorted.

[JayOh]

Mine is a 2011, can't remember the build month but it has the new black interior and steering wheel. I've also got the AEV 2.5" lift kit but it's not yet fitted.

I asked the mechanic if he thought the brake lines were ballooning and he is confident the lines are ok and the problem is elsewhere. His next step was to try and isolate the ABS pump. Hopefully I'll get an update today.

[Banshee]

I replaced mine with longer, but braided steel ones.

[RLT]

Originally Posted by JayOh

Mine is a 2011, can't remember the build month but it has the new black interior and steering wheel. I've also got the AEV 2.5" lift kit but it's not yet fitted.

The build date should be on the sticker on the middle pillar when you open the door.
Mines 2009 registered but built in April 2007
Stood for 2 years before I bought it cheap in a clearance when they had a Govt scrappage scheme.

[Mudgee hunter]

Try taking it for a run, get it up to say 80kph, knock it into neutral, hold revs at 2000rpm, and brake.
If it feels better, and the brake pedal pressure seems normal / better,
I would be looking at the vac lines.
Meaning they might need a modification perhaps.
Larger/ smaller diameter etc perhaps.
Did this model have a typical brake vacuum hose take off point on the Inlet to prior models?
Mack trucks and Peugeot has a bloody reverse bleed process!