Automotive Air Conditioning Information Forum (Archives)

henryk2112 on Mon July 12, 2010 1:40 PM

Year: 1983
Make: Oldsmobile
Model: 98
Engine Size: 5.0
Refrigerant Type: R134a
Ambient Temp: 110
Country of Origin: United States

For some reason, my manifold gauge set doesn't fit on the high side. Here's the story.

I bought the r12 to r134a conversion fittings. I installed the fitting on the low side, no problem. When I went to install the high side, the fitting was defective. It was late in the day, so I decided to just measure the low side as I couldn't hook up to the high side. It would not thread onto my original R12 port. The manifold gauge fitting is too large.

I got luck, as I've had cold air for a year and a half. I still think I might my charge might be slightly off, so I want to check it.

Obviously I need an adapter, but I have no idea what. I would really like to get an accurate high-side reading. What adapter do I need? Any help would be appreciated!


Thanks!

mk378 on Mon July 12, 2010 1:52 PM

Up to around 1986, the low and high side R-12 ports on cars were the same size (1/4 inch flare). Later R-12 models used a smaller high side (3/16 inch flare) to discourage mis-connection. Because of this situation, high side conversion fittings are sold for both sizes of original car fittings. You just need to buy a 1/4 inch one instead of the 3/16 you have now.

henryk2112 on Mon July 12, 2010 4:42 PM

Thanks,

What would the part number be so I can order it from here?

mk378 on Mon July 12, 2010 5:05 PM

This one. Unless you need an angled one because of space. Ideally you would remove the stock valve core from the R-12 port before installing this fitting, but since your system is already charged, you can just screw it on top. The valve core should have a "tail" that opens your stock valve when coupled.