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Discussion Starter · #1 · (Edited)
Is my truck supposed to have a cooling fan???? Think I fixed it,A/C

I only have the fan on the engine. I do not have an electric one pushing air through the radiator, condenser, and cooler for the turbo. I'm having a/c problems that's why I'm asking. Thanks
 

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No, have you had you a/c checked?
 

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check the coolant level in your ac. may just need a recharge
 

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Discussion Starter · #4 ·
This is what I've done so far. Replaced the accumulator/drier and the orifice tube liquid line (the tube that runs on the pass. fender). I then pulled a vacuum and let it sit for 30 min and checked for leaks, it was good. Then I charged it. I got 24 ounces in it (it holds 32 total) and my psi on my both my high side and my low side were through the roof!!!!! What I'm confused about is that the high side port is after the condenser, which makes me think that there is a blockage after that port. Does that sound right??? Thanks
 

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Discussion Starter · #5 ·
One more thing, truck running, a/c on. When the compressor kicks on the high side goes up and the low side goes down. When the compressor kicks off the high side goes down and the low side goes up. Keep in mind that the pressures are very very high. I pegged out my high side gauge 500 psi. They were both in the danger zone of my gauge.
 

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Mopar1973Man.Com
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Normal to some extent... The thing is typically the fan clutch should be locking up and aiding in pulling the air through the coolers. Even my truck there is a partial lockup of the fan clutch and the pressures will fall on the high side. But it still can get hot enough to be cycling on the high side from high heat days and traffic. But typically I still hold about 45-50*F in the vents.

Now when I charge A/C system I normally want a cooler morning to do it in so I can get the compressor to run solid lock and not cycle at 1,500 RPM's. and low side pressure of 35-40 PSI no more! Then checking the center vent temp it should be 40-45*F if done right.

Vent temp.


Inside and outside temps.
 

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Discussion Starter · #8 ·
Thanks to all. Mopar Man, I charged it last night, it was about 90 and very humid. When I put the first can of 134 (12oz) it started to blow cold. Then I put in the second can and noticed that it wasn't blowing cold anymore and checked the gauges and it was high on both sides. High, very high, so I stopped adding. On my way to work this morning I thought of trying the a/c figuring that going 55 would help aid in cooling the condenser. No luck truck still blows warm out of the vents.
 

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now i was told the other day tat if you have 2 different kinda of freon in there they react and its makes it not very cold. also that it may not be cold because there is to much liquid and not enough gas and its creating tons or pressure and working the ac pump a ton
 

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Discussion Starter · #10 ·
OK that makes sense to me. How would I remove everything and start over? Remember I put a vacuum on both sides, not really sure if that would remove all gas and liquid but I'm willing to try anything. Thanks
 

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Freon naturally boils and turns to gas under a vacuum. Just like water will too. If your going that far pull the compressor, drain the oil out and refill the compressor with a 8oz bottle of PAG oil. Then when you recharge the system DO NOT buy freon with oil! Only use freon. I know there is a ton of products out there with oil added and if you add too much oil your screwed! The system can pump the oil but oil doesn't create cold either.

This is fine...



This is NOT...
Replaces lost refrigerant & oil to A/C system
You don't want this!
 

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Discussion Starter · #12 ·
That's exactly what I bought. Just plain 134. No sealer,dye or oil added.
 

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Discussion Starter · #13 ·
Just went out and checked the condenser. It seemed clean as a whistle. Was able to easily blow compressed air through it (very very carefully). I also visually inspected it and it looks clean, no clogging. I cleaned the outside of it anyway. Next question is it at all possible for the compressor to charge the system backwards? Which would explain the low side being so high. Maybe the reed valves are bad???? Can I bench test the compressor? When I replaced the accumulator I was able to very carefully blow air through the evaporator. I also just cut the old orifice tube out of the liquid line hoping to see it all jammed up with crap. NOPE clean as can be, just a little oily.
 

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If your pressure is too high just try removing some of the 134.
You should have a sight glass in your system so when there almost no bubbles flowing you should be OK.
Just to have the AC checked there should be little or no cost if the shop is good and know what they are doing.

Checking my Porsche with vacuum didn't show a leak. The vacuum held a rubber to metal tubing but when under pressure there was a leak. Cut the hose back and used a couple hose clamps. 3 years now without adding any more 134.

My '95 Dodge Dually cools great.
 

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You should have a sight glass in your system so when there almost no bubbles flowing you should be OK.
Sorry Dodge Ram trucks don't have a sight glass.

Got to go by hi and lo side pressures on the gauges. Lo side pressure should be 35-40 PSI at 70*F outside temp.
 

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op if both of your pressures are high you have too much of a charge in the system. the high side high pressure switch is shutting the system off!
 

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Discussion Starter · #17 ·
That's what I thought, overcharged. However,,,why would it be overcharged when I only put 24oz in? The system holds 2lbs which is 32oz. What am I missing here? I understand that ambient temperature does play a factor and like I said it was hot and humid and the dew point was about 70, which is high.
 

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R12 systems have sight glasses. crazy thing is my 01 has never been charged and still blows 38* out of the vents
 

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That's what I thought, overcharged. However,,,why would it be overcharged when I only put 24oz in? The system holds 2lbs which is 32oz. What am I missing here? I understand that ambient temperature does play a factor and like I said it was hot and humid and the dew point was about 70, which is high.
That's if you start from a vacuumed state. Did you pull a vacuum on the system before adding the freon?
 

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Discussion Starter · #20 ·
Yes I pulled a vacuum. I have an a/c vacuum, it will pull 25-28in. That should be good enough.
 
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