The refrigerant (R-12) charge is quickly checked by looking at the sight glass on the receiver/dryer (arrow), located in the left front wheel housing.
It may be necessary to loosen the receiver/dryer mounting clamps in order to rotate the sight glass into view.
— Start engine and turn A/C on to its maximum setting. With compressor running (clutch cycled on) view sight glass. There should be few or no bubbles visible in the glass. A constant foaming indicates that system charge is low. Streaks on interior of glass indicate that system is discharged.
If using an aftermarket refrigerant product to recharge the system, follow the manufacturer's directions closely. To prevent component damage, a totally discharged system must be evacuated (sometimes called pulling a vacuum) using special equipment before recharging. This removes any harmful moisture from lines and components.
Was this article helpful?
The History of Porsche Cars through its generational changes. A must have ebook for any Porsche fanatic, this ebook is a reference book for Porsche enthusiasts. Discover all there is to know about the greatest Porsches ever made. All models are fully described and illustrated providing a definitive production history plus an accurate guide to original specs and equipment.