Air ride is jacked

I have cylinders & dakota guages & the pressure used to be 174, now it only airs up to about 160 & 166 & the front drivers side pancakes & the rear drivers side follows. Its DANGEROUS. I obviously have a leak. But how come the pumps are only pressuring up to 160 to 166? I heard that anything over 150 is too much, but if its not over 150, then there isnt enough pressure to hold the car up.....Anyone out there know whats going on?