The air conditioning system can be prone to refrigerant leaks and failure of one or more pressure sensors. The AC pressure sensors should be checked for proper operation when ever the AC system is serviced.Google+
Car Problem Reports
Buick Riviera AC System Prone to Leaks/Pressure Sensor Failures
Buick Riviera Problem
Average Mileage: 95,950 mi (88,000 mi - 103,900 mi)
Visitor, 1996 Buick Riviera, 88,000 mi
ac was serviced 3 times . however after 5 days the freon had leaked out. although the tech had put a tracing die and after charging system could not find a leak with sniffer.....still a leak occured etc...HELP
A/C leaks replaced freon with sealer.