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· Registered
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Discussion Starter · #1 ·
Before I tell you my problem let me first say thanks to all you folks for monitoriing this forum and offering for free your expert advice. I'm a pastor and can't afford new cars so I've go to be able to repair and keep my machines running. Thanks!

I have a 1996 Chev Suburban 4x4 350. Last summer the AC stopped blowing cold air. Everything works fine just warm air instead of cold air.

So this week I went and got a recharge kit. I turned on the burb, turned on the AC connected the refrigerant (following the directions) can with pressure guage. The pressure was low--less than 10 psi. So I shot some into the system until it reach about 35psi. Then the compressor turned on (or engaged). Yikes, the pressure dropped back to 10. The compressor disengaged. The pressure went back up to 35psi. Back and forth every 5 seconds. (I think they call this short cycling). So, I thought the system needed more R-134A so I took the pressure up the 45psi. Then the compressor would engaged and drop down to about 20ps. I drove it around no cold air. The compressor would just go on and off.

The problem is that I cannot add more A-134A because I'm at 45psi and that is in the Yellow on the gauge that says "Alert" don't add more refrigerant.

So now what? do I have a bad compressor? How to I get the compressor to stay engaged so the refrigerant will cycle through and equalize the pressure.

Any help or thoughts would be appreciated.

Robert (bigbob94)

· Super Moderator
3,521 Posts
It's all a matter of playing the waiting game. When you put refigerant in, you're putting it in on the low side. When the compressor kicks in, it starts circulating it, and the low side gets low on the pressure again. When the compressor kicks out, the pressure should rise back up. If the pressure when the compressor kicks out is ok, let it sit for a while. It'll slowly kick in and out, pulling more refigerant onto the high side. Keep adding more till you get to the reccomended pressure when the compressor is kicked in. Also, make sure the fan is on high, ac switch it, and either recirc is on, or max air is on (whichever the vehicle is equipped with). I apologize if the directions are a little fuzzy, I have a diffcult time describing processes like this... I also invite everyone else to fact check me on this...

· Premium Member
1,124 Posts
Crawdaddy is rihgt on. The pressures need to be checked with the engine running and the compressor clutch engaged. The Suburban has a big system, so it may take a bit of freon to get it back up to proper levels.
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