sruggling with brakes

[karl]

on a 2015 mrk 8

ended up with this job from another garage who had changed the rear brake caliper and discs etc their diagnostics wouldnt connect to the abs etc etc

anyway i have the headache of the job now

so after going threw everything, my diagnostics wont communicate with the abs module either but will let me bleed etc brake lines

i have had all the wiring apart check for corrosion in the pins etc all fine

i have just changed the master cylinder and still carnt get a pedal at all

i have brake booster fault code and pcm and abs communication fault codes

am thinking the abs is knackered but before i go and get another

would like dome pointers before i do just incase i have missed something

[karl]

sorted this

its was a faulty rear brand new brake caliper

[V184]

sorted this

its was a faulty rear brand new brake caliper

So you changed the master cyl for no reason ?

[karl]

sorted this

its was a faulty rear brand new brake caliper

So you changed the master cyl for no reason ?

yes i did

[dumper]

It does happened you expect a new component to be ok even original parts from Ford had it many times over the years .

[MinorMatt]

How does a dodgy caliper stop the diagnostics communicating?