A/C question
Safety Car
Joined: Jun 2002
Posts: 4,738
Likes: 2,485
From: Buckeye, AZ
St. Jude Donor '12-'13
Originally Posted by BarryK
hi guys
Got back from Carlisle last night. Great show for all of those that couldn't make it but a bit wet on Senday.....
Anyway, brought the '78 back home as it didn't sell which is making the wife very happy. About a 100 miles trip home which is the longest drive the car has seen in YEARS. She ran good I'm glad to say except one thing.
With the A/C on it makes a very noticeable "rattling" noise. Switch off the A/C and it goes away, switch it back on it immediatly comes back. Very annoying!
I had the A/C system completely gone over after I got the car running again in the spring and he replaced the drier/accumulator, replaced all the O Rings, vacuum pressure tested it, and refilled it with freon. It blows nice and cold and works great, almost too cold, but this rattling noise is driving me crazy.
Any ideas??
A friend suggested it might be the bearings on the A/C compressor??
Got back from Carlisle last night. Great show for all of those that couldn't make it but a bit wet on Senday.....
Anyway, brought the '78 back home as it didn't sell which is making the wife very happy. About a 100 miles trip home which is the longest drive the car has seen in YEARS. She ran good I'm glad to say except one thing.
With the A/C on it makes a very noticeable "rattling" noise. Switch off the A/C and it goes away, switch it back on it immediatly comes back. Very annoying!
I had the A/C system completely gone over after I got the car running again in the spring and he replaced the drier/accumulator, replaced all the O Rings, vacuum pressure tested it, and refilled it with freon. It blows nice and cold and works great, almost too cold, but this rattling noise is driving me crazy.
Any ideas??
A friend suggested it might be the bearings on the A/C compressor??
Thread Starter
Le Mans Master
Joined: Apr 2004
Posts: 7,106
Likes: 38
From: Newark DE
maybe it's normal but it's sure annoying!
Besides, I think at least checking the belt tightness is a good idea as I was never sure I was able to get that belt tight enough anyway when I put it on.
Besides, I think at least checking the belt tightness is a good idea as I was never sure I was able to get that belt tight enough anyway when I put it on.
Race Director
Joined: Feb 2005
Posts: 16,100
Likes: 17
Originally Posted by BarryK
maybe it's normal but it's sure annoying!
Besides, I think at least checking the belt tightness is a good idea as I was never sure I was able to get that belt tight enough anyway when I put it on.
Besides, I think at least checking the belt tightness is a good idea as I was never sure I was able to get that belt tight enough anyway when I put it on.
IE: Belt length between pulleys (7-10")belt deflection= 1/4" ...(13"-16") = 1/2" deflection....
Only issue with my original GM compressor many years ago is I destroyed clutch as forgot A/C was on going 125 mph +....heard a noise(loud) and stopped..metal filings were all up in hood blanket...
Last edited by rihwoods; Aug 29, 2006 at 01:03 PM.
Thread Starter
Le Mans Master
Joined: Apr 2004
Posts: 7,106
Likes: 38
From: Newark DE
well, had a few spare minutes and just checked the belt tension on the AC compressor. the top of the belt that runs from the top of the compressor pulley to the top of the WP pulley has a deflection of 1/2" on a belt length of approx 8"-9". Should be 1/4" deflection for it is a bit on the loose side.
Later today I'll try tightening it up some and see if it makes a difference.
Later today I'll try tightening it up some and see if it makes a difference.
