AC Compressor Leaking

[shft22]

The AC on my car never worked since I got it, after checking pressures I found the system completely empty. I pulled vacuum but that lasted about 5mins, so major leak somewhere.

I put about 100lbs of air and started to look for a leak with water and soap, and of course it couldn't be a simple o-ring somewhere, instead the compressor is leaking. Looking under the car from the center of the car I can see bubbles from the top area of the compressor. I am attaching a picture that shows the location.

Any ideas? Is this a new compressor deal, or is there something up there that can be tighten.

Screenshot 2026-06-20 at 12.55.13 PM.png (2.68 MiB) Viewed 47 times

[dr bob]

I don't have your car, but do have the same compressor. If that's the hose manifold connection, it bolts to the compressor and does seal with o-rings under the manifold plate, so it's a relatively easy fix. Use modern green o-rings of course.

----

Over 25 years ago I did the R-134a conversion on my car, and didn't realize there are o-rings there. The initial AC charge was great for almost a day before there was a pretty spectacular discharge at the mounting flange. The new POE oil pretty much decimated the old buna o-rings from its R12 days. A lesson not easily forgotten. Fixed with new pieces, properly torqued manifold plate, another evacuation and refill, and its been reliably cold ever since with not a lot of attention.

[NC944er]

I agree the leak appears to be stemming from the compressor's bolt-on manifold connection. The original o-rings were made of black rubber that hardens over time.

Check out part number: 94412693501, often listed as "A/C O-Ring (20 X 2.5 mm) for Compressor Service Fittings."

If you're going generic, the o-ring specs are:

• Inside Diameter (ID): 20.0 mm

• Cross-Sectional Diameter (CS): 2.5 mm

• Outside Diameter (OD): 25.0 mm

Green nitrile is best when converting to R-134a. Pelican Parts and FCP Euro have them for about $1.00 apiece, you'll need 4 o-rings total. Coat lightly with refrigerant oil during installation. The A/C compressor should be removed for clear access to the hex key bolts, so you might as well replace the o-rings for the barrier hose connections and add in a new receiver drier while you're there.

[Tom]

^^what he said^^

See pictures from my old compressor. Your leak is almost surely from the o-rings under that bolt-on manifold -- which I always think looks like an elephant's face

acrepair-manifold.jpg (317.71 KiB) Viewed 34 times

ACRepair-orings.jpg (367.2 KiB) Viewed 34 times

[shft22]

Well sir, you were right on the money. Take a look, two of the four o-rings were completely destroyed.

IMG_9553.jpg (3.65 MiB) Viewed 32 times

IMG_9552.jpg (3.71 MiB) Viewed 32 times