Brake problems, end of my tether, please help

[gresham4wheeldrive]

Brake problems can be incredibly frustrating, especially when symptoms keep changing. Start with the basics: check brake fluid level and condition, look for leaks, and inspect pads, discs, and calipers for uneven wear or sticking. Also make sure the ABS sensors and wiring at each wheel are clean and intact, as faults there can cause multiple warning lights and odd brake behavior. If everything checks out mechanically, a proper diagnostic scan is usually the quickest way to pinpoint what’s actually causing the issue.

[bluecaddymaxi]

Unfortunately, same (or very similar) problem, here : 2012 Maxi life - 99,000 miles


loss of brakes (more & more spongey) whilst in France last Sep/Oct
no evidence of leak or loss of brake fluid (at any time, then or since)
pressure bleeding / replacement of brake fluid (at local garage)

brakes restored (as good as I've known with this vehicle)

on way home (across about 1,000km), brakes spongey again
off the ferry - about 100 miles from home, pedal (clacks) almost to no pressure
tiniest increase in pressure if 'pumping' the brakes

at home, local garage inspects system & vcds
master cylinder replaced & fluid (re)bled
braking restored

(personally not convinced it won't happen again)

a few hundred miles later (over Easter weekend), brake pedal spongey
soon, am virtually without brakes *

* abs traction control (letters 'abs' & 'skidding car') lights are illuminated
vcds at local garage suggests left rear wheel sensor fault

wheel sensor replaced
pressure-bleeding performed (again)
fault lights now off

brakes ok : not brilliant, but as good as I can remember

of course (once again) I'm not totally convinced
test run today ; is pedal getting easier to press ???????

in meantime, investigating abs pump parts - in case brakes are lost a fourth time