a/c issue

[curtis13]

i have a 2000 f350 7.3, it has 300,000km , a/c blows cold for approx 5 mins then stops , have had pressure gauges on it , at first pressures equal while a/c cycles on and off then , it stops and high side pressure very low and low side pressure gets high just wondering if any common problems out there related to this , thanks for any insight