Back in the R-12 days there were some metal caps, on vehicle AC and even on some refrigerators. Yes, my 1980 Toyota R12 system has metal caps. And every home HVAC system I've owned had metal caps. But I haven't found any for R134a systems other than decorative ones. But if the plastic caps are desi...

On a 20 yr old vehicle it wouldn’t be a bad idea. Inside the caps there is a rubber seal. The caps will not leak after system pressure builds up. I know it seems impossible but it just works. I had 8 cars all lined up at my shop with all the owners standing by. Engines at speed. With caps off, 13 o...

The plastic caps are essential. I keep an assortment kit on hand because many of the cars we work on are missing them .Get a schrader tool and be sure your stems are snug, not tight. This may not make much sense but it works! I have never found metal caps I have the plastic caps on the service port...

For the past fer years I've had to top off the 134a in my 2000 Chevrolet pickup in the summer. I know both service port valves have a slow leak but I haven't wanted to evacuate the system to replace them. I've read that the service port caps are intended to be the primary seal and the service port v...