SERVICE PROCEDURE 'O' RING PUSH OUT DURING HI SIDE SW.

VEHICLES AFFECTED: 1988 - 1990 N AND J VEHICLES W/C60

Due to a stack up of tolerances between the high side pressure switch or sensor and the high side port, some difficulty may be encountered when replacing a switch or sensor with the refrigerant system charged. The Schraeder (R) valve may be depressed before the "O" ring is captured by the switch resulting in the "O" ring being pushed out of its sealing area causing a leak.

On vehicles with this condition, the "O" ring may be held in place by wrapping a string around the inboard side of the switch port while the switch is being screwed on (refer to Figure 1). This will hold the "O" ring in the switch port while the Schraeder (R) valve is being depressed. Once the "O" ring is captured, the string should be removed and the switch screwed on until fully seated. The joint should then be leak checked with a refrigerant detector.

Redesigned parts will be in production during the 1990 model year.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.