A/C compressor flinging gunk
 

Had my a/c recharged last Summer and have been using it intermittently since. The compressor seems to the slinging something all over my engine compartment and I can't figure out what it is. I thought it was grease, but it's hard and won't come off which makes me think it was hot when it was flung. Maybe it's pieces of A/C clutch (looks like some gunk between the pulley at the front of the compressor) or belt material? It damaged the finish underneath it, so I'll have to sand and repaint. Any idea on what this could be?

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They all do that. Get out the wipes after a drive.
It’s compressor oil

I have to disagree, my A6 does not sling anything. Are you still using R-12 ?

Using 134a.

A friend of mine had a 72 GTO with A/C . It had a shield over the clutch to prevent that issue. The only one I ever saw. It looked like a GM piece. He said it was.

You can buy those. Ecklers. Repop

I've seen those, but not on a Pontiac. The substance isn't oily, it's rough and baked on. Anything to be concerned about in terms of longevity of the compressor? Sounds like it might be common if they make a shield for it.

It is indeed oil from the front seal on the compressor. It has always been a common problem even 40 years ago. As long as the leakage is minor it won't be a problem for AC performance. Eventually it will get worse and the system will be loosing refrigerant. At that point you will have to decide to either install a new seal (which in the future will leak} or install a newer designed compressor.

The front shaft seal assembly is a multi-piece affair including a felt pad that is supposed to collect and hold oil that leaks out. Unfortunately, they don't do the best job and what you are showing on the hood looks like thousands and thousands of others out there. Before these cars were collectable, we never worried about it and wiped it off every now and then. The underhood blankets all had a stripe like that. The hard residue you describe may be a combination of belt dust, the ceramic part of the seal failing, and oil and rubber baked to the hood. It does look like the belt may be a little narrow for the AC pulley. Here is a pic of the ceramic seal, the felt pad and the rest of the assembly on the front shaft.

Appreciate the info. It's the first time in the 30 years that I've owned this car that I've consistently used the A/C. The compressor is about 15 years old, but the system wasn't charged until about a year ago. At any rate, the A/C seems to working fine and holding a charge. Maybe I'll get one of those shields an effort to keep the gunk down.

According to some of my G.M. manuals the compressor is supposed to weep. Many Buicks with the A-6 have covers that contain this and direct the small amount of discharge to the ground. I copied one from a friend of mine who got one off a Buick in the junk yard and installed it on his 66 GTO. I've got one on my 63 Catalina and my 69 H-O Lemans.
My buddies GTO
https://www.pro-touring.com/attachme...1&d=1245466161

There is an improved front seal. It's ceramic and double lipped. But if it has a bad leak, the front shaft bushing/bearing is worn and allowing the shaft to wobble around.

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Can you change the seal without having to evacuate the system?

Actually that's 2 Buick V-8 shields welded together for better protection on my GTO there.

NO. You have to evacuate the system, since the seal is what keeps the refrigerant inside the compressor.


There's a modern lip seal that will work-- AlmaProducts.com makes new A6 compressors and they supply them with lip seals, which can be also retrofit to old A6's. Below is an email I got from Alma when I asked them if their seals fit old compressors:

"I had my engineer review your request and he said the service kit 73-027S would absolutely work for you.

The service kit includes the two piece nose cone seal, o ring, snap rings and felt seal.

I have a dealer here in Michigan that can help you get one ordered.

The dealer is –

Thermo King Michigan

955 76th St SW

Byron Center, MI 49315

Phone 616-878-4900

Email – parts@tkmichigan.com"

Here's mine. Is still R12.

It does look like I could use a wider belt.

Months later this problem turned into a catalyst for an engine rebuild and engine bay detail. With a clean engine bay in the works I want to prevent this from happening again. Looking at my options:

1) Buy a reman compressor (unknown internals)
2) Rebuild the clutch and clutch seal on this compressor (haven't done one before)
3) Find a shop to rebuild the compressor (I assume there are nuances to putting one together to make them last)

The easiest path is to buy a new compressor, but I don't want to buy one that's going to leak again. My existing compressor works fine, it just leaks. So I'm wondering which is the most pragmatic approach to eliminate future slinging gunk?

Did you read what I wrote about GM compressors where the service manual says they are supposed to weep?

Did you read HGerhardt says there is a new fix for this problem? Here it is again.


There's a modern lip seal that will work-- AlmaProducts.com makes new A6 compressors and they supply them with lip seals, which can be also retrofit to old A6's. Below is an email I got from Alma when I asked them if their seals fit old compressors:

"I had my engineer review your request and he said the service kit 73-027S would absolutely work for you.

The service kit includes the two piece nose cone seal, o ring, snap rings and felt seal.

I have a dealer here in Michigan that can help you get one ordered.

The dealer is –

Thermo King Michigan

955 76th St SW

Byron Center, MI 49315

Phone 616-878-4900

Email – parts@tkmichigan.com"

Having worked in a Pontiac dealership in 1970 on the grease rack, the stripe on the hood, or insulation pad under the hood from the compressor weeping is completely normal. I was working on cars that were new, or less than 5 years old for the most part, they all wept from that seal. If they didn't leak, the person either wasn't using the A/C, or it was out of R12.

The shield was implemented to stop that stripe, because customers that actually got under the hood would see it, and surmise that something was wrong with the A/C compressor. The service manager would then attempt to explain that it was a normal occurrence, which wasn't particularly easy to explain to someone that was still making payments on their car with a factory warranty still in effect.

Should've re-read my own thread! Thanks, I'll reach out to them.