AC Air gap Question
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Junior User
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AC Air gap Question
Hi All,
Been having a problem with my AC running cold for 20 minutes or so then it blows but its hot air, then 10-15 minutes later it kicks back on cold.
I did a search on here and saw a post saying the air gap should be about .025, well my gap was .055, so I did what the poster said and took out the "shim" aka washer and now my gap ia a tight .016.
I ran the truck for over 25 minutes and it blew cold and never went to hot air, can I or what is the harm in running this with no shim in here? Can I hurt anything?
I then for the hell of is took a soda can (aluminum) and used that as a shim and now my gap is about .022-.024.
I am leaving for a 600 mile tow on Thursday and will need AC and just need it to get me to Ohio and back and then can have a buddy look at it.
Thanks for any and all help.
Rich
Been having a problem with my AC running cold for 20 minutes or so then it blows but its hot air, then 10-15 minutes later it kicks back on cold.
I did a search on here and saw a post saying the air gap should be about .025, well my gap was .055, so I did what the poster said and took out the "shim" aka washer and now my gap ia a tight .016.
I ran the truck for over 25 minutes and it blew cold and never went to hot air, can I or what is the harm in running this with no shim in here? Can I hurt anything?
I then for the hell of is took a soda can (aluminum) and used that as a shim and now my gap is about .022-.024.
I am leaving for a 600 mile tow on Thursday and will need AC and just need it to get me to Ohio and back and then can have a buddy look at it.
Thanks for any and all help.
Rich
Postmaster
Joined: Dec 2005
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First off you have a FAST Grand Nat. I love those cars. Second off, i heard that just taking the shim out will get you buy for some time, but the clutch will go eventually. I think youll be fine with ur soda can shim.
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Hi John,
Thanks for the kind words.........looking to put the car into the 8's this weekend in Ohio but if it is hot then I dont think it will happen till Labor Day here in Jersey.
Thanks for the feedback on the AC, I just have to make it AC wise to Ohio and back and will get it looked at.
Thanks again and stay well.
Thanks for the kind words.........looking to put the car into the 8's this weekend in Ohio but if it is hot then I dont think it will happen till Labor Day here in Jersey.
Thanks for the feedback on the AC, I just have to make it AC wise to Ohio and back and will get it looked at.
Thanks again and stay well.
Hotshot
Joined: Jan 2002
Posts: 17,988
Likes: 207
From: La La Land
Turn your A/C to "off". Start the engine and go look at the clutch.
Notice that most of it is turning? Look at the "front" of it, the face closest to the degas bottle. Notice it ISN'T turning?
Turn on the A/C and look again.
The space between what wasn't turning and what IS turning now is called the air gap. It's only thousandths of an inch, but it has to be there to cycle the compressor off, and it can't be too great because there's an electro-magnet that pulls it in to engage it. When the air gap gets too great, the magnet won't dependably pull it into engagement.
Pop
Notice that most of it is turning? Look at the "front" of it, the face closest to the degas bottle. Notice it ISN'T turning?
Turn on the A/C and look again.
The space between what wasn't turning and what IS turning now is called the air gap. It's only thousandths of an inch, but it has to be there to cycle the compressor off, and it can't be too great because there's an electro-magnet that pulls it in to engage it. When the air gap gets too great, the magnet won't dependably pull it into engagement.
Pop
Last edited by SpringerPop; Jul 30, 2007 at 11:46 AM.
Hotshot
Joined: Nov 2006
Posts: 11,286
Likes: 263
From: North of Greenville
Ahhh... I haven't looked yet, but I understand waht you're talking about. What has to be removed in order to adjust this gap to the proper setting? I assume that it's not too difficult??
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Hotshot
Joined: Jan 2002
Posts: 17,988
Likes: 207
From: La La Land
The bolt that's directly in the middle of the shaft comes out (it's normal right-hand thread), and then the clutch plate pulls straight out. It's splined onto the shaft.
Make sure you know how much air gap you need to reduce first. Measure and do the math. You want to have at least .025" when you're done.
Some compressors have multiple thin shims, some have a single thicker one. I was lucky to have an assortment kit of precision "bearing shims" here, which I used to get this very close to optimum, but if you have a single shim you may have to carefully file or grind it to proper thickness. Insure that the two "faces" remain reasonably parallel.
Simply removing all the existing shims is NOT the answer!
I do not have the torque spec for re-tightening that center bolt, but I put it back together with a quarter-inch ratchet set (to avoid over-torquing), and used a bit of "weak" (blue) LocTite on the threads first.
Pop
Make sure you know how much air gap you need to reduce first. Measure and do the math. You want to have at least .025" when you're done.
Some compressors have multiple thin shims, some have a single thicker one. I was lucky to have an assortment kit of precision "bearing shims" here, which I used to get this very close to optimum, but if you have a single shim you may have to carefully file or grind it to proper thickness. Insure that the two "faces" remain reasonably parallel.
Simply removing all the existing shims is NOT the answer!
I do not have the torque spec for re-tightening that center bolt, but I put it back together with a quarter-inch ratchet set (to avoid over-torquing), and used a bit of "weak" (blue) LocTite on the threads first.
Pop
Last edited by SpringerPop; Jul 30, 2007 at 12:35 PM.
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Laughing Gas
Joined: Jul 2004
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ok thanks. I have been narrowing this down for the last 2 weeks. I started out a little low on refrigerent. toped that off and put in the heater bypass valve. Very cold at idle stoping at a store for 2-3 mins letting it run on max high and i would get back in and it would be cold. then it would warm up as i was driving. So i just checked the gap and it was larger than i had feeler gauges for. i only had up to like .048 and still had some considerable gap to each side so i removed the 1 big shim and put it back together i am somwhere around .03? I did noticed on the part that comes off does have grooves worn into it like a brake rotor when the pad falls of so my guess is that it was slipping under a load. Or is that normal to have a groove in them over 200K miles?
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Originally Posted by mustang_gt_350
so do you have to remove the belt to remove the center bolt?