Soft brakes issue

[Sur2799]

Hello all

got a 2006 sprinter 2.2cdi
Replaced pads and callipers got stuck
Replaced callipers
Bled the whole system
Brakes were still spongy but only with engine on


Just replaced the master cylinder and bled it

pedal still sinks with engine on only
Engine off pedal stays solid
Engine on it starts sinking and brakes get spongy
The car has no leaks anywhere has been bled correctly

anyone have any idea what this might be?

 

[curious]

Went through all that (and more) with my 2007 Vito.

In the end it was corrosion on the caliper holding brackets. The steel had laminated rust that had expanded impeding the pad movement. (The clue was the uneven pad wear.) Knock/chip/grit blast or whatever, to get rid of the rust. Also, make sure the caliper sliders are free moving. The lower ones on each side of mine were far more reluctant to move than the upper ones.

Now the brakes are so ****** sharp they're almost too sharp.

 

[curious]

Seriously? 'bl00dy' gets the star treatment?

 

[EmilysDad]

Seriously? 'bl00dy' gets the star treatment?

 

[Sur2799]

Caliper sliders are luckily brand new as they are in the caliper itself. Il take the brackets off and give them a good clean. Fingers crossed it works as I’m getting so fu*king annoyed with it now

 

[curious]

Trust me, I know your pain.