1990 Lincoln Continental Lift Control, Compressor problem

Switch is in trunk, yuck, but I have to overfill the air, especially in back then turn switch off, and it will stay for a while, but when it falls, it falls. There is a small leak drivers side back wheel, I can hear it, but you can lift it above the leak, then it will fill up. I then have to let air out of the front because when it is overfilled, the brakes don't work very well.
Is the computer in the compressor, and where are instructions or diagrams of the air hoses, and how the compressor should be hooked up?

Thank you

Sue