On a 1987 Buick LeSabre, the low-pressure AC recharge port is typically located on the
dryer/accumulator. This is often a cylindrical canister near the front of the vehicle, usually on the driver's side, somewhere in the engine compartment. It will have a smaller fitting than the high-pressure port. Look for a schrader valve; it's usually a smaller valve with a protective cap.
Important Note: It's *crucial* to identify the low-pressure port correctly. Connecting to the high-pressure port can be extremely dangerous. If you are unsure, consult a repair manual specific to your 1987 Buick LeSabre or take it to a qualified mechanic. Improper AC recharge can damage the system.
