Acceptable Amount of AC Compressor Oil Leakage.

[Bill C.]

the car I just purchased has an original AC system. It may have been charged over the last 30 years, but all the parts are as installed.

it spent most of the last 20 years barely driven (like less than 1K miles).

So I figured I be the guy to buck/end that trend.... :-)
I drove it a good 500 miles with the AC on and off...

What I found is some oil slung up on the backside of the hood and on the inner fender.

If some seepage is normal, just how much is "ok".
last thing I want to do is take it on a trip and kill the AC.

If it should be near zero - where can I get an old style front seal?

I got one of the aftermarket top shields to keep oil of the hood and inner fender. - just a temp fix.


Thanks in advance - Bill

[Jim T.]

Re: Acceptable Amount of AC Compressor Oil Leakage.

Bill, Does you Corvette have original type R12? If it does it would save money to find a repair facility that can recover R12 to save it if the front seal is going to be replaced. The front seal is available but from reading the service manuals special tools are required to remove and install a new front seal. The front seal can be removed and replaced with the compressor remaining on your Corvette.
Corvette air conditioning systems do not require much oil. The oil required for R12 is different from what the R134 systems use. Does your receiver/dryer have a sight glass to view the charge status of refrigerant?

[Bill C.]

Re: Acceptable Amount of AC Compressor Oil Leakage.

Jim -

car is r12. I'm 99.9% sure its old school ether type of oil.
i have not looked for the sight glass, but I'm pretty sure the factory dryers do have it. will check that in the am tomorrow.

i can have my buddy who owns an AC repair place do the work.
But I was told years back (when doing my old 72) that the new style front seals aren't worth a flip.
the old ones are made differently and hold up better.

thanks for the input.

bill

[Harry S.]

Re: Acceptable Amount of AC Compressor Oil Leakage.

the car I just purchased has an original AC system. It may have been charged over the last 30 years, but all the parts are as installed.

it spent most of the last 20 years barely driven (like less than 1K miles).

So I figured I be the guy to buck/end that trend.... :-)
I drove it a good 500 miles with the AC on and off...

What I found is some oil slung up on the backside of the hood and on the inner fender.

If some seepage is normal, just how much is "ok".
last thing I want to do is take it on a trip and kill the AC.

If it should be near zero - where can I get an old style front seal?

I got one of the aftermarket top shields to keep oil of the hood and inner fender. - just a temp fix.


Thanks in advance - Bill

Bill, there should be no leaks. When the oil gets on the bottom of the hood it can weep through. The paint will start to bubble. The only fix is to replace the hood. I would suggest having the compressor rebuilt. Most folks just replace the front seals but a complete tear down and restoration will make it like new.

Good lust.

[David H.]

Re: Acceptable Amount of AC Compressor Oil Leakage.

Bill, there should be no leaks. When the oil gets on the bottom of the hood it can weep through. The paint will start to bubble. The only fix is to replace the hood. I would suggest having the compressor rebuilt. Most folks just replace the front seals but a complete tear down and restoration will make it like new.

Good lust.

+1 Several threads on CF, Digital Corvette, Corvette Action Center, etc ... on AC compressor oil soak and paint bubbling on hood with the only real fix replacing the hood.

[Bill C.]

Re: Acceptable Amount of AC Compressor Oil Leakage.

no bubbles or paint damage.

i'm probably the 1st person to run the AC in 20+ years.

it is a 2 owner, 68,400 mile documented original car.
engine still has original intake runner gaskets with the GM warranty tabs.......

the compressor just needs a front seal. my guess it got messed up when I kicked on the AC. probably got hard from sitting so long.

Bill

[David H.]

Re: Acceptable Amount of AC Compressor Oil Leakage.

[QUOTE=Bill Chamberlain (47576);751149]no bubbles or paint ... /QUOTE]

Point was to remove as much of the oil as you can, as soon as you can. Before it soaks through.

[Richard M.]

Re: Acceptable Amount of AC Compressor Oil Leakage.

Your front seal is probably dirty and scratched from non use then being put into action as you're thinking.

The original front seal is actually a 2 piece ceramic seal, much like water pump seals. Later replacements were a lip seal which I have never used but others discouraged their use. Allegedly, it did not correct excessive oil seepage. I would suspect over time the lips can create grooves in the shaft and deem it un-serviceable in the future. Removal later is also troublesome. Discussions.

Original type seal. This is a NOS GM replacement. I bought several many years ago to service my wife's car which uses the GM A6 compressor.
P1010002.jpgP1010004.jpgP1010006.jpgP1010014.jpg

Several are available there on Ebay....Here's one. It includes the wick.
!B+uk45wBmk~$(KGrHqUOKkEEzLrCmYbpBN!lv236O!~~_12.JPG!B+uk71wEWk~$(KGrHqIOKkYEzldvy++)BN!lv+ZScQ~~_12.JPG

A small amount of oil seepage is typical, by design, to keep the seal lubricated. When the seals wear and weep too much oil the wick gets saturated and oil spins out everywhere.
In the nose of the compressor just in front of the seal is a cylindrical felt wick. This wick is designed to capture any spent oil to prevent it from splashing onto the clutch and outside areas.
The wick is shown below in the background on the paper towel. This one was heavily saturated as seen by the excess oil on the towel. It can be cleaned using denatured alcohol.
P1010008.jpgP1010013.jpg

Since the R12 and oil should be purged, cleaned, and refilled, I would recommend the unit be removed and serviced on the bench to ensure proper installation. It is tricky enough to replace the ceramic without damage as it is. It is important not to contaminate or scratch the seal.

Toolkits are available for the DIY'ers also. I got this one years ago for about $50 shipped IIRC.
P1010011.jpg

Your friend that can service the unit may already have tools to do this. As mentioned, I'd have him take it off the car to work on it easier.

Rich

[Bill C.]

Re: Acceptable Amount of AC Compressor Oil Leakage.

Rich...

MANY MANY THANKS!
based on your post, I will have him remove the entire unit.

I ordered a NOS kit off eBay last night, was fairly cheap (only $13.00+ship).
It has all the parts from your picture.

Bill