AIR CYLINDERS BENT?

I HAVE A FRIEND WITH A 98 CIVIC WITH AIR CYLINDERS AND WHEN YOU LIFT THE REAR IT FALLS BACK DOWN,IT WAS ONLY TWO VALVES IN THE REAR SO TO SEE WHAT WAS LEAKING I SET THE VALVES UP TO LIFT THE R.R THEN L.R THE R.R WAS FINE BUT THEN THE L.R WOULD DROP SLOW THEN ALL OF A SUDDEN JUST DROP,HE SAID IT WASNT THAT BAD CAUSE HE DROVE THE CAR 30 MIN TO MY HOUSE BUT NOW IT JUST WONT STAY UP,IS THE CYLINDER BENT?ALSO THE CAR IS PARKED BACKWARDS IN MY DRIVEWAY THAT HAS A BIG INCLINE COULD THE WAY ITS PARKED HAVE ANYTHING TO DO WITH IT,LIKE TOO MUCH STRAIN PULLIN ON IT FROM THE INCLINE?