I fitted 312mm brakes to the front of the car a week or so ago, I bled the brake and it was percect. 

 

My pedal was going spongy on Wednesday so I had a look underneath and the rear N/S caliper was leaking out of the handbrake mechanism and by the piston.

 

Fitted a new caliper today and I have bled all four corners twice now in the correct order furthest from master cylinder to closest. No air is coming out at all now.

 

With the engine off the pedal is rock solid, the moment I start the engine the pedal goes spongy and with a bit of pressure sinks to the floor. If I pump the pedal quickly it goes solid but looses pressure.

 

Anybody else had an experience like this? A google suggests either master cylinder has decided to die or there is air in the system still. 

air in rear calliper lines, remove calliper and hang it higher up then pressure bleed again. This gets the air locks out

57 minutes ago, JWvrs25 said:

air in rear calliper lines, remove calliper and hang it higher up then pressure bleed again. This gets the air locks out

Thanks, will give it a go tomorrow