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AC Problems

B_to_C

B_to_C

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I have a 1990 Jimmy with a 350...

Last week I went to turn on the AC and the truck stalled. So I revved up the motor then tried to turn the AC on and the belt started squealing. What's my problem and what's my fix? /forums/images/graemlins/bow.gif
 
take it out, haha not sure of your problem but if its not too hott where u live i would take it out, lightens the truck
 
Seized compressor. Only solution is to install another one. /forums/images/graemlins/frown.gif
 
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Seized compressor. Only solution is to install another one.


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Darn. Was there any way to prevent this or is it just something that happens? And would it be ok to get a compressor from the junkyard or do i need to get a rebuilt one? And I wouldn't have to replace anything else right?
 
I would recommend a rebuilt compressor. Since you have a '90, unless the system has already been converted, it is a freon system which leads to a whole new set of problems. Now is a good time to convert it to 134.
 
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Seized compressor. Only solution is to install another one.


[/ QUOTE ]

Darn. Was there any way to prevent this or is it just something that happens? And would it be ok to get a compressor from the junkyard or do i need to get a rebuilt one? And I wouldn't have to replace anything else right?

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When the compressor grenades it usually sends a bunch of crap into the system. You will need a compressor, an accumulator/drier, and an orifice valve. You will also need to flush the entire system before putting it all back together.
 
If you convert to r-134a i would highly suggest you change out the condensor as well, to allow for the better cooling that 134 needs, i fight my ac system every year since i converted, it just does not get cold from stop light to stop light and when idling, does fine on the highway though.
 
Actually, these truck condensors are pretty big. A parallel flow one of the same size would be better, but still, there are other things to consider first. This is a little off topic, but since this guy is looking at some major re-work anyway, why not?

First of all, make sure you are using the right orifice valve. If you use the white one, it will never cool right to begin with. White is for R-12, which has bigger molecules, so you would need a bigger compressor with R-134. A slightly smaller orifice tube is better, but the VOV is better yet. This really helped my idle vent temps. You also have to adjust (or replace) the low pressure switch when converting. Then it's time to look at your fan(s) to make sure you are getting good airflow at idle. You may also find bumping the A/C-on idle speed up a bit helps.

After all of these basics are out of the way, then you have a true picture of whether or not your hardware is adequate for your climate and use.
 
Like said above, the A/C pump probably locked up but here is a simple way to tell.... take your hand, grab on to the front of the pump(not the clutch) and try to turn the pump, a good pump will be tight but should turn slightly. Obviously if it won't turn after giving it all you have then it is endeed locked up. Another thing far as the 134A conversion....we did it to our C30 and I was very disapointed on it's performance. When I redid the A/C in my K5 at the last minute I decided to go with a freeon called FREEZE12. It does NOT contain propane or any other explosive chemicals like most R12 substitutes. It works pretty dang well in my blazer and we are running it in about 10 of our semi trucks. It doesn't cool quite as good as R12 but better than a converted R134 system IMHO.

Another thing is good luck getting the orifice tube out, some slide right out and some don't, I was a lucky one( /forums/images/graemlins/rolleyes.gif) and mine came out in pieces with needle nose pliers, tried heating up the tube with a torch and it blew right out with compressed air.....shrunk the tube and the new one wouldn't go in, tried boring out the tube...yada yada...wound up buying a brand new evaporator with the orfice installed. /forums/images/graemlins/rotfl.gif YOurs SHOULD come out farely easy with the system just working.

I'm pissed myself, one of my lines cracked the other day and I lossed all my freeon /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif I refuse to drive the K5 without A/C. /forums/images/graemlins/shame.gif Good thing is I am going to refill it with true R12 once I get the new line in tommorrow.
 
A stuck orifice tube is indeed something to look out for. There are a few things that everyone should know when working on them:

1) there is a special tool for pulling them. If you can't get it out, don't break it with pliers if you can get your hands on one of these.

2) If you do break it, be sure to flush all of the parts of it out of the evaporator before proceeding.

3) There are repair kits available. You cut off the inlet to the evaporator where the orifice tube is and throw it away. The repair part attaches to the inlet tube with a compression fitting and holds a new orifice tube. Autozone has them for $20. This saves you from replacing the whole evaporator. Plus if one gets stuck again you can take it apart and poke it out from the back.
 
Uggh, this seems like a major PITA. Maybe I should just take my top and doors off when it's hot out and install an on-board air compressor instead /forums/images/graemlins/dunno.gif
 
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Uggh, this seems like a major PITA. Maybe I should just take my top and doors off when it's hot out and install an on-board air compressor instead /forums/images/graemlins/dunno.gif

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I thought the same thing too when I was rebuilding my A/C system but once you understand how it works and what it takes to make it work, A/C's become quite easy. Just get a new compressor, pull off the dryer and orafic tube, get some a/c flush and blow it through the hoses, evap, and condensor with compressed air until it comes out clean.
Replace the dryer and orafic tube with new ones, add 8-10 ounces of oil to the system and split it between the compressor and condensor, have the system checked for leaks, vaccuum it down, charge it with the correct amount of freeon, and enjoy riding in a nice cool truck while you watch everyone else sweat it out with the winders rolled down. /forums/images/graemlins/thumb.gif
 
When I replaced the compressor on our '94 Sub last summer I did all the work, then had the folks at Brakes Plus (attached to Advance Auto Parts) put it on their vacuum machine for an hour. They only charged me $25. /forums/images/graemlins/cool.gif Six /forums/images/graemlins/eek.gif cans of R-134 later and it was blowing cold again. /forums/images/graemlins/thumb.gif
 
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