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AC Issues

My truck is a 98 Taco SR5 V6 5VZ-FE, the AC Compressor goes out. I replace the compressor and research what oil to put in(PAG), how much

1.9oz, and then had PepBoys recharge it. During the recharge, the technician tells me that when he hooked up to the low side, it showed 85psi, and that was too high, he's not touching it... I convinced him and he continued. When done, the AC blows cold for 5 minutes, then gets hot. I put a pressure guage on it, and it's showing 75psi for me, which is too high. Now, after a couple of days, when the motor is cold in the morning, it blows cold for 15m, then gets hot. In the middle of the day when motor is hot, no coldness at all...

My questions are: How many oz of PAG SHOULD the system have? How did he "over charge" when he's got a better guage then me? Is there an easier way of evacuating a system than having a machine doing it?

Am I right in assuming, it's got too much oil, not enough refrigerant, and too much pressure?

BTW, the expansion valve was changed as well and is NOT clogged, for the record.

Thanks, just curious....

RedForeman with 176,356 miles and going strong.

Reply to
RedForeman
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Hi Red I'm leaning towards an overcharge of gas try with the gauges connected bleeding off some gas and things should improve bleed slowly as if you go too fast you will remove oil as well. the alternative is to drain and start again this time bleeding in the gas using the gauges and stop when the pressures are correct not the weight method, I usually fill to 75% of recommended weight and finish off with the gauges. Good Luck Joe

Reply to
Jodabo

Red, does the the low side pressure show 75psi with the system on or off?

Reply to
qslim

Was the air that entered the system when you changed the compressor evacuated before you charged? A deep vacuum needs to be pulled on the system before recharge. You could try just letting the air & refrigerant blow out of a high spot on the system and recharge the refrigerant just until the compressor no longer short cycles. Of course, the right way is to fully evacuate the system and recharge the correct weight of refrigerant.

Ken

Reply to
Ken Shelton

When I first hooked up the guage, it DID show nearly 75psi... and that just didn't seem right...

I think I put too much oil in it, because when it was charged it didn't take but 8-10oz of refrigerant, and the sight glass was milky, and someone said that is when it's got too much pressure, or too much oil, and not allowing the mixture to expand correctly.... Does that sound right? I asked someone and got another opinion too... the more the better...

I think I'll drain the compressor and start over with MUCH less oil...

thanks guys.

qslim wrote:

Reply to
RedForeman

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