I pulled apart the master to check it because it didnt have pedal hardness until the end of the stroke , but that means the pedal was hitting the plastic and my foot was extended way to much
After i fitted it back together i had no pressure.
Even used the vac on the caliper nipple and cycled atleast 100ml of new fluid through, still nothing.
What worked was taking the rear caliper off the swing arm and bolt it on the foot peg bolt , and a zip tie around the hose\frame, clamp frame in the pads to stop them moving
This allows the bleed nipple to be the absolute top of the system now.
I could have used the vac bleeder but i had a syringe also which i used.
I kept sucking oil out and filling the reservoir and got a great bleed first go.
Literally spent hours messing about until
said put the caliper higher, then first go and it was perfect.
If your back brakes are spongy, you might need to try this and cycle new fluid through.