ok fitted a sunny b310 booster to my 1200

i have landcruiser 4 piston front calipers and r31 rear discs and calipers, and a 240k 7/8th master
without the booster the pedal was very hard

but now with the booster fitted i could pretty much throw my show at it and the brakes will lock up, as in there is NO resistance other then the return spring on the pedal

also the booster is only running off one port on my L20b as ive got twin 40s and the manifold only has the one provision

so any one offer some insight as to why the pedal is now so unbelievibly soft?
also feels like the booster or master is bottoming out, all soft then pedal just hits a wall....but its not any where near being on the floor and the pedal used to only travel an inch if that without the booster