James11111

Thanks for the input, my thoughts were that if it was air, I should be able to pump the pedal to get pressure so if it pressurises then gradually sinks to the floor, it is fluif leaking past a seal.

hi, thanks, I didn't but i repaired the leak in my EZbleed pressure bleed kit and used that to bleed the caliper which appeared to run bubble free. I have since clamped the hose and the pedal still sinks. I had to use mole grips with a slit bit of hose to protect the flexi but am not sure if it was properly clamped as I didnt want to wreck the flexi. I have ordered a proper clamp but am worrid it's the master cylinder now. Same questio though, used genuine MC is about £15, new Meyle one is £55, which is the best option?

Hi, after 25 years of working on cars including full engine conversions, I have been defeated by a rear brake pad change. The issue started when naively winding back the piston on my caliper, it started ok then hit a stop and wouldn't budge. I'm more inclined to understand why rather than brute force it so a quick search showed me that I need to engage maintenance mode on the EPB. I attempted to wind the EPB back with VCDS and for some reason got an error but in a moment of madness, I then clicked on the stop procedure option as I had unsuccessfully started it. I heard the motor running and went outside of the car to realise that the motor was obviously spinning until it reached a hard stop but the caliper was removed at this point so the piston just wound all the ray out and brake fluid started to seep from the piston dust seal. I somehow managed to wind the piston back in and instead of messing around with vcds, i popped the motor off the back and wound it in manually which allowed me to wind the piston back in. I thought all was well but this is where the real issue starts. As I had lost fluid, the brake pedal felt spongy so I proceeded to bleed the caliper. Something has gone horribly wrong and I really need help deciding what to change first. I have a pressure bleeding kit but it leaks a bit so I bled the caliper manually. Now the brake pedal is soft and when pumped a few times, will go hard and slowly sink to the bottom which I assume means I have wrecked a seal. Is it likely the caliper or the master cylinder? I mean how likely is it that the MC suffered seal damage when manually bleeding the brake vs the seal around the piston becoming damaged when blindly screwing it back in whilst still on the car. The MC looks like a pain to get to so now im thinking about changing the caliper and my next question would be. should I get a genuine used one from ebay for about £40 or should I get one of the cheap but new ones that come in at around £60, are these cheap Chinese rip offs? are they dangerous to use? Is a functioning genuine used one a better option? Thanks for any input, the car out of action is an absolute disaster abd what should be a 30 minute job has ended up in misery and expense.