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

[spoondog]

To me the fact that it pulls to the left under braking suggests there may be an issue with the right hand calliper I would be looking to see if the brake pads are wearing evenly on both sides just to eliminate that.

Sent from my SM-T805Y using Tapatalk

[JayOh]

Am I missing something here?

I was poking around under the bonnet and noticed this loose connector and an empty mounting point.

Is there anything significant missing from here? It's probably unrelated but I'm slightly hopeful this is where the magic brake fixing module should be..

[Fishframe]

Originally Posted by JayOh

Am I missing something here?

I was poking around under the bonnet and noticed this loose connector and an empty mounting point.

Is there anything significant missing from here? It's probably unrelated but I'm slightly hopeful this is where the magic brake fixing module should be..

Looks like a port where a dealer would plug in some sort of diagnostic tool. Maybe for bleeding or something?

[st_za]

It looks like a 3 pin electrical connector so it might be a connection to a pump or something that needs to operate at a variable rate but I have never seen anything plugged into it on any RHD JK's so it's most likely unrelated to your issues. Mine has never been used - I can tell by all the dirt still caked onto it

Out of interest, does the brake pedal feel firm and unresponsive directly after startup when you unplug the power for the vacuum pump? Or does the pedal feel the same, regardless of vacuum pump assistance?

[JayOh]

Originally Posted by st_za

Out of interest, does the brake pedal feel firm and unresponsive directly after startup when you unplug the power for the vacuum pump? Or does the pedal feel the same, regardless of vacuum pump assistance?

That's not something I've tested - how do you unplug the booster? Is that the hose to the right of the master cylinder?

[Banshee]

Can it be pressed all the way to the floor when running?
Or is it just long travel before you are braking hard enough to trigger the ABS?

[st_za]

The vacuum pump is behind the front bumper, mounted to the passenger side frame horn from the factory or around that spot for aftermarket bumpers. The plastic power plug has a clip that you need to depress to pull it apart (don't break it by pulling it apart forcefully like me).

Have you tried a different JK for comparison? It won't help you diagnose the problem but it will give you a better idea of what it should feel like when it's fixed and when all the incremental fixes you do have made it good enough.