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'07 4L V6 4x4 A/C problem

1726 Views 12 Replies 4 Participants Last post by  The_Pope
I've just spent the last couple of hours reading everything I could find related to my problem. So now I have a list of things to locate and check. I'll give you an overview, maybe someone can save me some time (and $$$s).

First off. I know nothing about air conditioning, but I am willing to learn.
Last year the A/C seemed to be 'weak' (not as cold as before), so I made a mental note to get it checked - not a good idea at my age.

This year I get cool air on 'max ac' and on regular ac at all fan speeds, so I decided to buy a recharge kit. Managed to find the low side connector and hooked everything up. The instructions said I should see around 30# with the engine off but the gauge went 'off the clock'. Checked that I was on the right fitting and tried again, same result. As the refrigerant was OK for the atmosphere (and me) I decided to carefully bleed off the high pressure. With the pressure down to about 10# I recharged it to 35#, started the engine and put the ac to max. Same as before, cool air but not cold.
I can hear the ac clutch kicking in, it is noisier than I remember. Where did the high # at the low side connector come from? Is that a clue to the problem?
I'd appreciate any help, comments, directions to previous post, verbal abuse etc that may help.

Senior Citizen Al.
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With a working system, pressure at low side should be higher than 30 psi with system off, but should be about 30 psi with system running. But the fact is that you cannot fix an AC system with those little kits, in fact you can cause thousands of dollars of damage if that contained any "sealer".

You need to take your truck in to a real AC repair shop.

One needs a real gauge set up, leak detectors, vacuum pump, evacuation/recovery equipment to do AC work correctly and safely.

I decided to carefully bleed off the high pressure.
See, even that above was against environmental regulations throughout the world, and you have zero idea how much refrigerant was lost. A repair would've measured your temperature, then pulled out your refrigerant and weighed it, the ONLY to KNOW if refrigerant level was OK or a problem.
Thanks Cusser.
I will be taking this to a shop. I figured there may be some simple fix I could try first.
You could inspect all visible AC connections and crimps for oily residue which would indicate a leak, maybe even use soap bubble solution at those locations to locate a leak. A shop will look for leaks, maybe even add some UV dye, if the refrigerant ounces are lower than specifications. They may add dye and refrigerant and ask you to bring back in a few days too.
Found a local shop with a great reputation.
Took them about 40 mins to run a diagnostic, purge the system, check for leaks and re-fill. Works like new for $150.

Thanks for the help.

What did they diagnose as bad and then fix? Help us here to learn !
It IS possible for "normal" leakage from the compressor seal - necessary to lubricate the seal - could account for that loss over 9 years. Hopefully OK for another 9 years.
Aircon needs to be run 20 minutes a month whether you need it or not. Keeps the refrigerant oil circulating and keeps the inside of the hoses in good condition.
Pope is correct about routine AC use (and/or defrost on most vehicles which kicks on the AC), helps keep the compressor seal lubricated.
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