Soft brake pedal

Hi
I have renewed the front brakes rears are good
Had the brake fluid changed but the pedal is still soft I'm thinking i need a new master cylinder but just wanted to see if there's any other areas to check
Cheers Chris

How old are your brake lines, that is the rubber bits?
But it isn't unusual for MC's seals to go and by-pass fluid  instead of pushing it.
And are you sure that all the air is out of the lines?

Be Warned, that when you remove the MC from the cars booster to take the nuts off equally, and specially going back as if you fully tighten one side then the other you can pop the booster pin out of the keepers.

So off 4 turns on one then 4 turns on the other repeat often till there isn't any more of the nuts left on the Stud.






You have to carefully unbend the fingers, then reposition the pin, then tighten the figers over it.

If you keep the brake pedal pressed hard does it slowly go down?

With the engine off pump the brake pedal a few times till it goes hard then press and hold it down and start the car, if the pedal drops a little then you know the brake servo is working.

four pair of mole grips 8 2p pieces ciamp each
flexy if the pedal goes hard release one at a time
when the pedal goes soft that is the wheel with
the problem worth a punt in my opinion