The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 08-05-2016, 01:42 PM   #1
davepl
Registered User
 
davepl's Avatar
 
Join Date: Aug 2006
Location: Redmond, WA
Posts: 6,332
Is my AC compressor the cause of my leak?

After about 250 miles I have a slow leak in my AC system and a great deal of oil slung off the front snout of the reman iron compressor.

I know a certain amount is "normal", but I have a lot after only 200 miles so if it were 20,000 miles and I had 100X, you'd be swimming in it.

What are the odds that the compressor is the cause of my leak? I have new (not reman) aluminum A6 to go on it, and I'm wondering if that's going to cure my leak. Time will tell, but I'd like to know my odds!
__________________
1970 GMC Sierra Grande Custom Camper - Built, not Bought
1969 Pontiac 2+2 427/390 4-speed Coupe
1969 Pontiac 2+2 427/390 4-speed Convertible
davepl is offline   Reply With Quote
Old 08-05-2016, 03:04 PM   #2
67 chevelle
Registered User
 
67 chevelle's Avatar
 
Join Date: May 2013
Location: WEST PALM FLORIDA
Posts: 1,174
Re: Is my AC compressor the cause of my leak?

What are the odds that the compressor is the cause of my leak?

better than average
__________________
68 Long Fleet , ly6 , turbo 350 , 3-5 drop , original paint , front discs
67 Small window , 7 foot bed , tweaked 6.0 LSX 2004R Medium Olive
58 Apache fleet , 235 , offy intake , dual exhaust , 4 on the floor , red/white
69 Long Fleet , Custom , 6.0, 4l60 , AC , Medium Olive
67 chevelle is offline   Reply With Quote
Old 08-05-2016, 04:18 PM   #3
Big Kev-O
Registered User
 
Big Kev-O's Avatar
 
Join Date: Mar 2014
Location: Simi, CA
Posts: 495
Re: Is my AC compressor the cause of my leak?

That is most likely your issue. You should not see a drop of oil at 200 miles. As somebody who repairs A/C the best tool for finding leaks is a bubble type detector like Big Blu. It's basicaly a soap that bubbles very easily. It's cheap and can be found at locally. Spray it on and watch for tiny bubbles. Spray gently to avoid creating bubbles right out the sprayer.

If you want to leak test on the cheap mix about 50/50 water and some dish soap. Soak the area you suspect and look for an endless trail of tiny bubbles.
__________________
Made in America by Americans
Big Kev-O is offline   Reply With Quote
Old 08-05-2016, 04:58 PM   #4
F.A.A.benny
Registered User
 
Join Date: Jul 2015
Location: Euless, Tx
Posts: 431
Re: Is my AC compressor the cause of my leak?

Ive seen reman compressors that sling oil pretty quick. Even new Frigidaire compressors on brand new cars back then would have oil coming from the shaft seal. Some cars even had a cover on the clutch. Shouldn't be a ton of oil being slung unless the reman compressor was too far gone. Or it could be missing the wick. Without that wick, oil will sling much quicker. A double lip seal would also help instead of the ceramic seal. How else do you know you have a small leak? The new aluminum a6 replacements use the newer shaft seal which helps prevent the oil leak.
F.A.A.benny is offline   Reply With Quote
Old 08-05-2016, 05:04 PM   #5
davepl
Registered User
 
davepl's Avatar
 
Join Date: Aug 2006
Location: Redmond, WA
Posts: 6,332
Re: Is my AC compressor the cause of my leak?

I had it charged, and then within 6 weeks or so it was low/weak, so I bought a can of parts-store recharge with a gauge that showed it quite low. So I topped it off, it was cold for another month, now starting to blow warm again. That's about all I know for sure.
__________________
1970 GMC Sierra Grande Custom Camper - Built, not Bought
1969 Pontiac 2+2 427/390 4-speed Coupe
1969 Pontiac 2+2 427/390 4-speed Convertible
davepl is offline   Reply With Quote
Old 08-05-2016, 05:16 PM   #6
F.A.A.benny
Registered User
 
Join Date: Jul 2015
Location: Euless, Tx
Posts: 431
Re: Is my AC compressor the cause of my leak?

Did you vacuum the system when you had it charged the first time and if so how long? I like to leave the system in a vacuum for at least a few hrs or more because sometimes a slow leak may not show up in a 30min to an hour vacuum. If I suspect a leak, I charge the system with nitrogen and use the soapy water test. if I still cant find the leak I suspect the evap may have a leak. Since its the only thing that doesnt get soapy water as its in the case. Was your system open the elements for a long period of time?
F.A.A.benny is offline   Reply With Quote
Old 08-05-2016, 06:32 PM   #7
davepl
Registered User
 
davepl's Avatar
 
Join Date: Aug 2006
Location: Redmond, WA
Posts: 6,332
Re: Is my AC compressor the cause of my leak?

It would hold vacuum for hours just fine, but overnight it would bleed down. So it's a very slow leak.

It was open for years, but vacuumed down and charged after the new dryer and o-rings and so on.
__________________
1970 GMC Sierra Grande Custom Camper - Built, not Bought
1969 Pontiac 2+2 427/390 4-speed Coupe
1969 Pontiac 2+2 427/390 4-speed Convertible
davepl is offline   Reply With Quote
Old 08-05-2016, 07:40 PM   #8
F.A.A.benny
Registered User
 
Join Date: Jul 2015
Location: Euless, Tx
Posts: 431
Re: Is my AC compressor the cause of my leak?

Quote:
Originally Posted by davepl View Post
It would hold vacuum for hours just fine, but overnight it would bleed down. So it's a very slow leak.

It was open for years, but vacuumed down and charged after the new dryer and o-rings and so on.
If it was open for yrs, I wouldn't be surprised if the evap leaked. I would also suspect condenser but you mentioned in the post that you have a parallel flow condenser. I would also suspect the hoses if they were drier rotted.
F.A.A.benny is offline   Reply With Quote
Old 08-05-2016, 08:09 PM   #9
davepl
Registered User
 
davepl's Avatar
 
Join Date: Aug 2006
Location: Redmond, WA
Posts: 6,332
Re: Is my AC compressor the cause of my leak?

Why would you think the evap leaked? Based on what? Just curious.

Hoses looked OK. They're old, but not all cracked up.
__________________
1970 GMC Sierra Grande Custom Camper - Built, not Bought
1969 Pontiac 2+2 427/390 4-speed Coupe
1969 Pontiac 2+2 427/390 4-speed Convertible
davepl is offline   Reply With Quote
Old 08-05-2016, 08:55 PM   #10
F.A.A.benny
Registered User
 
Join Date: Jul 2015
Location: Euless, Tx
Posts: 431
Re: Is my AC compressor the cause of my leak?

Ive pressure checked easily over 200 evaporators and with the vast majority of them being oned that have been open to the elemants or many yrs. Id say about 3/4 of them leaked. Many of looked perfect from the outside but they seem to corrode from the inside out. I would get it flushed and pressure checked.
F.A.A.benny is offline   Reply With Quote
Old 08-05-2016, 09:42 PM   #11
1972RedNeck
Registered User
 
1972RedNeck's Avatar
 
Join Date: Jan 2011
Location: Townsend MT
Posts: 1,725
Re: Is my AC compressor the cause of my leak?

I have never had any luck with most reman A/C compressors. They all leak refrigerant within the first year. The only ones that are any good are those remaned by John Deere.
__________________
1966 F250 4X4 416
1972 K20 350 4 OTF
Quote:
Originally Posted by GASoline71 View Post
I once pulled an intake manifold for a cam swap... ended up with a full on drag car that ran in the 11's.
1972RedNeck is offline   Reply With Quote
Old 08-05-2016, 09:54 PM   #12
prodjay10
Registered User
 
Join Date: Jun 2016
Location: Phoenix AZ
Posts: 429
Re: Is my AC compressor the cause of my leak?

The condensation on the evap causes corrosion. Also if open to the air for a long time, the air mixed with the oil can become acidic. Ideally you'd check for leaks by pressurizing with nitrogen. Fix leak, vacuum, recharge.
prodjay10 is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 10:25 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com