Air Conditioning - Lack of Cooling

91ford25

Article No.
91-20-12

10/02/91


^ AIR CONDITIONING - LACK OF COOLING - OIL STAINS AROUND A/C COMPRESSOR HIGH PRESSURE RELIEF VALVE - TRUCKS WITH GASOLINE ENGINES

^ AIR CONDITIONING - VENTING OF REFRIGERANT THROUGH THE A/C COMPRESSOR HIGH PRESSURE RELIEF VALVE - TRUCKS WITH GASOLINE ENGINES


LIGHT TRUCK: 1987-91 BRONCO, F-150-350 SERIES
1988-91 F SUPER DUTY, F-47


This TSB article is being republished in its entirety to correct the Dealer Coding, Basic Part Number.

ISSUE: There may be a loss of A/C refrigerant through the A/C compressor high relief valve during idle and stop-and-go traffic conditions. Eventually, there may be a lack of cooling and oil stains may appear around the A/C compressor high pressure relief valve.

The excessive discharge pressure is caused by the recirculation of higher temperature engine compartment air passing through the condenser during idle and stop-and-go traffic conditions. Normally, cooler ambient air passes through the condenser. Since the refrigerant in the condenser cannot be sufficiently cooled by this high temperature air, excessive head pressures are created causing refrigerant to be vented through the high pressure relief valve.

ACTION: Replace the radiator lower air shield, located between the lower radiator support and the front bumper, with a new radiator lower air deflector (F1TZ-8327-B). This new air deflector is larger than the old air shield and will minimize the amount of hot air recirculation through the condenser. Refer to the 1991 Bronco, Econoline, F-Series, F-Super Duty Truck Shop Manual, Section 01-08, for service details.


NOTE: TO REPLACE THE DEFLECTOR ON OLDER VEHICLES, IT WILL BE NECESSARY TO DRILL HOLES, FOLLOWING THE HOLE PATTERN IN THE NEW DEFLECTOR, BEFORE IT CAN BE ATTACHED.

PART NUMBER PART NAME CLASS

F1TZ-8327-B Radiator Lower Air Deflector C

OTHER APPLICABLE ARTICLES: None
SUPERSEDES: 91-14-13
WARRANTY STATUS: Eligible Under Basic Warranty
Coverage
OPERATION DESCRIPTION TIME
912012A Install New Air Deflector 0.4 Hr.
DEALER CODING
BASIC PART NO. CONDITION CODE
8327 55
OASIS CODES: 208000, 208200