AC 7000 Throwing A/C Belt

I would think the hissing @ the compressor would be normal as the high & low pressures equalize.

I'll take a picture tonight for you

Got the new idler on, and at first it seemed like everything was going pretty well.  Let it run around at high idle for a minute, and noticed the whip starting to come back, but it was more of a twang this time with an occasional jump.  Well, shut it down, tightened the belt a little more, and started it back again, and this time it was pretty quiet at idle, so I put it up to around 1500 rpms and came back to watch, and the belt was really moving around, then it jumped right off after less than a minute.  I quickly shut the tractor off and went to turn the compressor by hand, and it felt like turning over a large chainsaw or other single cylinder 2 stroke motor.  Difficult for about 1/2 of the turn, then felt like it went over TDC and was pretty easy again (I had to look again to convince myself I didn't have a single cylinder York compressor up there!).  I'm starting to think I have a compressor that has something wrong internally.  Shouldn't an A6 be pretty consistent turning resistance the whole way around being an axial piston compressor?

Your system still had pressure so would turn hard. How did it turn after it set for a hour?
Change the dampener.      MACK

Mack (and all others), if the balancer is causing the belt whipping issue, would it do it both with the compressor engaged and disengaged, and if the compressor is causing the issue, would it only whip when the compressor is engaged?  Also, when you say change the balancer, is that because the rubber has become dry rotten and swelled a little at the edges?  I'll try to check the timing marks on the pump vs the crank to see if I have any slippage.  I looked yesterday, and it looked like it was spinning pretty true, so I'm not sure if the heat had my eyes deceiving me or if where the tractor is kind of dark, that's playing tricks on my eyes.  I think Dale starts back up in July with rebuilding them, would it be a good investment to have it done even if it doesn't show any symptoms of slipping?

No worries, I appreciate the picture.  It looks like the 7020 has a little different accessory belt path than the 7000, but the A/C is the same.  My alternator is on the tractor's left side.  I will hang onto this photo in case it comes down to adding another pulley.  Oddly, the side that whips the most is the side with the tensioner on it.  The worst part is between the crank pulley and the tensioner.  I'm contemplating a new compressor since it feels like it is only compressing about 1/2 of the rotation, whereas an axial compressor, it should feel like a pretty consistent torque all the way around.

Look at it like this....nothing wrong with having a new compressor

Pop the top off the cab find the bulb for the txv pay attention to location on the tube remove the bulb from the suction line start up tractor check pressure then stick bulb in cup hot water after couple min check presure then switch to cold water after few minutes check pressure switch back and forth couple times txv valves will some times stick or plug up the hot cold back and forth opens and closes full if it goes to working you can let it run but eventually it will do it again ( guarantee when it's hot as hell and you got lots to do )is when it will

But if the belt bounces when the compressor is disengaged (ac off), then it ain't that as it is just acting like an idler pulley. Which I then gather from other posts it is your dampener.

A Fridgidaire A6 is an axial style compressor. It has 3 double acting pistons on a swash plate for 6 cylinders total. If you're familiar with a hydrostatic pump, the basic designs are the same. The drag should be fairly even turning by hand. That long belt stretches under load. With a missing stroke or two, it's stretching and releasing giving you that dance.

Edited by Lonn - 29 Jun 2018 at 6:53am

Great thread.Especially since I'm resurrecting the ac in my 7010.

I would go Sanden without question. They are a very popular unit known for efficiency and reliability. Not that it's an issue on a tractor engine, but a Sanden will tolerate up to 6000 sustained RPMs, making them the go to unit for classic car upgrades/retrofits.

The small dial to the left of the red tape says R 134a. I used a 1 gallon pump sprayer w/ straight water to clean the heater and evaporator cores. I also used 3/4 Pex ball valves in the heater hoses. They fit tight in the hose.  I have that sun tint film come down about 12" from the top of each window. Tim  

By the way, I just replaced the compressor on my 7000 about a month ago.  I got a rebuilt A6 unit from o'riley auto parts for about $156 and it fit perfectly. It even has a warranty.  It is the same one that they put on a 78 chevy silverado pickup. Part number is 57094. Everything lined up nice and it works well.