a/c noise

A/C ASTRO 1989 makes noise ... still works but how do i fix ac compressor bearing noise ????????

take it to a mechanic and have them check the compressor. I've had two outcomes with screaching compressor bearings. On my Jeep, a lubricating additive added to the freon took care of it. On my '89 Astro, the compressor digested itself pretty quickly and spewed metal flakes through the system. I had to have the whole system rebuilt.
moral of the story is, don't run the A/C when it starts making noise and don't wait too long to have it checked out.
I don't recommend taking a do it yourself approach to this, unless you have the special tools and equipment to reclaim the freon and purge the system. The lubricant I mentioned cost me $35. The A/C rebuild $1700.