I am attempting to vacuum the A/C system after replacing the receiver/drier. The system was previously converted from R12. There is an R134a adapter on the low/suction side port but there is no adapter on the high side port- just the brass cap on an a brass port. The FSM details pulling a deep vacuum first on the gauge manifold low side, then opening the manifold valve to draw a vacuum on the high side. I see two problems. First, without the high-side port adapter, I can't attach the quick-disconnect fitting and follow the FSM procedure. Secondly, I won't be able to read high pressure while charging the system even if I just pull a vacuum from the low side.

I've looked all over the internet for the right R12-to-R134a port adapter (high side) and I can't seem to find the right part. I have a handful of adapters from auto parts stores but none will fit properly on the existing R12 port. The adapter on the low side is fine- I did have to replace the valve core (source of a leak) which is why I lost refrigerant and why I replaced the receiver/drier.

It's a Hitachi compressor, if that adds anything. the photo shows the two brass ports and the low side adapter. the high side adapter shown only catches a couple of threads or so and the flare surfaces are touching but it is the right thread size/pitch.

Any advise or part leads would be appreciated.

Edited June 14, 201212 yr by Willoughby Z
spelling. add'l info and pic

I meant to say that the flare surface of the port "is not seating" inside the high side adapter.

Take one of the High Side adapters and cut or grind off 3 or so millimeters from the base so that it will be able to seat. 'Dry fit' in a vise first to make sure that the adapter is engaging the original fitting and then install the adapter with JB Weld on the threads. Check again to make sure the adapter is engaging the original. After the JB Weld has cured, install back on the compressor using the brass lug to tighten. You should be able to attach the gauges at this point.

Thanks for the tip ZCurves...

I almost went that route. But I called a guy, "who knew a guy, who knew a guy..." and ended up at a small old-school auto parts shop who had a huge assortment of A/C fittings, adapters and more important- instant "I know what you need."

He tossed a FJC 2604 1/4 -F female HS across the counter for $5.17. I was high-rolling 'til I got home and discovered the can tap that should have been in the loaner service manifold kit was missing. :tapemouth

Two hours later, deep vacuum was finished, recharged and chilling at 48 degrees!

Thanks again...

I want one of those! Can you hook me up? PM me!

I want one of those! Can you hook me up? PM me!

PM sent.

Beware when you install. I removed the brass high-side port to clean the threads and put the adapter and port together with thread sealant.

After charging, there was a hissing leak when I removed the quick-coupler. I backed the adapter off a quarter turn and stopped the leak. There's no core valve in this adapter, so make sure that the inside shoulder flare of the adapter doesn't impede the the plunger of the port. When I first tightened them together, the valve movement felt okay. Not! When you dry-fit, you'll see what I mean.

Thanks for the info!

PM sent.

Beware when you install. I removed the brass high-side port to clean the threads and put the adapter and port together with thread sealant.

After charging, there was a hissing leak when I removed the quick-coupler. I backed the adapter off a quarter turn and stopped the leak. There's no core valve in this adapter, so make sure that the inside shoulder flare of the adapter doesn't impede the the plunger of the port. When I first tightened them together, the valve movement felt okay. Not! When you dry-fit, you'll see what I mean.

cheap quality retrofit adapters leak. those are the aluminum ones. here is a source for good quality ones in either brass or metal.

and the price is less than what they charge for the elcheapos. the best fittings are the ones where you remove the original valve core. the cheaper ones just have a dummy valve core that pushes in on the old original valve core. lots of problems there

because the dummy shafts sometimes bind and you get the hissing of freon. you can tap them sometimes with a small screwdriver

and get them to seat, but for the same price you can get good quality valve cores.

http://www.acsource.com/fittings.aspx

Edited July 3, 201212 yr by hr369

Thanks Greg. I'll look into it.

I still have a leak or have developed a new one. It's not at the adapters or at the receiver/drier connections which were the only items that have been disturbed.

I know, could be the hoses (original). I may have to go with a total overhaul/replacement of components-updating the expansion valve, etc.

A/C systems are a new functional area for me and I research until my eyeballs bleed... I'm learning.

Your choices now include injecting some fluorescent dye, pretending you're a CSI and putting on the yellow goggles and waving a blacklight around, or filling it up and immediately driving over to a shop with a "sniffer" that know's you're coming and is standing by. Might want to Powerwash everything first so you don't see OLD dye from the LAST guy who worked on it

Common leaks include schraeder valves and front seal on the compressor. Pinholes in the condenser from rock chips impacting.

Thanks Wade. Valuable advice. There are other cars in the clan that will be needing A/C services soon, I'm considering a tester for leak detection. I've also been locating and pricing all of the components, just in case.

Wade is right, follow those hints to save time...Don't forget to "sniff" or use the UV (black) light under the dash/in the center vent. Fingers crossed that it is not the front seal on the compressor - I hate that!!