Automotive Air Conditioning Information Forum

I'm still learning Automotive A/C repair and I've done some checks on various vehicles and noticed that most of them don't have a schrader valve inside the high side port. They have a tiny black rubber plunger inside the port and often enough they leak. The port cap seems to prevent them from leaking at all. I'm assuming as the system gets old the little rubber plunger gets hard and begins to leak. The port itself is not removable. Does this mean that one has to replace the whole line? Can it be modified to accept a traditional schrader valve?

The CAP is the real seal.

Kinda figured that out already, (POS engineering if you ask me. Do they really care about leaks and the environment)? Had caps pop and break with the center of the cap remaining inside the port making it almost impossible to remove. Are these ports removable???

Yes, you can buy the port with ball valve assembly inside- there is a tool for easy removal, but a pair of vice grips works just fine- be sure the port valve assembly casing that screws onto the line is threaded okay and tight- Three times in my life, I have attempted to remove a cap by unscrewing it- and the port assembly came with it- unknowingly- and the entire system charge spewed out, with green dye and oil everywhere- all this in front of the customer! and the service writer!! Makes me look like an entire idiot!! the port was not tight from someone before me!!

.......thanks for the heads up. That was definitely an entertaining and educational war story....your bad will be my good!
Thread sealant a good option?

DontKnowSquat wrote:Thread sealant a good option?

I wouldn't, wouldn't want to chance ANYTHING getting in the system.

The thought did cross my mind. Good ole teflon plumbing tape to the rescue??

DontKnowSquat wrote: The thought did cross my mind. Good ole teflon plumbing tape to the rescue??

No. Just let the cap do its job.

Teflon tape is only for tapered pipe threads.

I just cant use the OEM port it's going to leak eventually and uses the cap as a final leak prevention. That's just bad engineering in my opinion. Looked in my basket of do-dads and found a similar high side port with a schrader valve, (one on the right. The one on the left is the OEM POS). The diameter of my Frankenstein port at the o-ring is slightly smaller. But the threads match and so does the depth. I installed a secondary o-ring were the port meets the line's opening. A little Nylog on the o-rings and tightened enough so as not to come off when removing the cap. Pressurized it with nitrogen for an hour and it held. Released the Nitrogen and pulled a Vac down to 29 hg. So far, no leaks! SUCCESS!!