DanY

That is a good point. I'll get a new master cylinder.

I realise I have ordered Dot 5.1 brake fluid instead of Dot 4. Will I be alright to use it instead of Dot 4 as I'm going to completely replace all the brake fluid. I'll make a not that it's not Dot 4 for future changes. Is there any reason why I can't use Dot 5.1?

I checked the servo this morning by dipping a zip tie into the vacuum hose hole. There was no fluid in there which still leaves me confused as to why I have fluid behind the brake pedal. I've ordered a second hand servo and master cylinder anyway, so, with some new brake fluid to go with it I'm sure that will sort it. I ended up changing the rear discs and pads today as they needed doing. I found one of the calipers was sticking, I'm not sure if this would lead to excess pressure in the master cylinder hence the ever so slight leak behind brake pedal. I'll update when I've fitted the master cylinder and servo. 👍

I think I'm having the same issue. Brake pedal sounds like it is releasing gas when I press it but then becomes really hard to press it anymore. But interestingly I have found some fluid dripping down the boot of my brake servo behind the brake pedal. My thinking is that it must be a master cylinder that's gone bad for it to be leaking fluid. Is that right? Is it worth replacing the servo as well if there is fluid inside the servo? I'm going to investigate vacuum hoses tomorrow and I'll check if the servo has fluid in it. Have I missed anything? Anyone else had this problem?