Automotive Air Conditioning Information Forum (Archives)

boomyal on Sat August 15, 2015 4:36 PM

Year: 2006
Make: Ford
Model: Explorer V8
Engine Size: 4.6
Refrigerant Type: R134
Ambient Temp: 76
Pressure Low: 15/58
Country of Origin: United States

I bought myself an 18 oz can of R134 at Wally World for $23, It came with a gauge and hose. This morning I went out and started the 2006 Explorer up and turned the air on to it lowest temperature setting. I also turned the fan on high. The outside temperature was 76°.

I immediately noticed that the compressor was cycling on and off every few seconds. I thought that to be odd. I hooked the pressure gauge up to the low pressure port and every time the compressor cycled the pressure would go from about 15 lbs (off) to 55 lbs (on) It did this repeatedly. I left the gauge hooked up and turned off the A/C. The pressure went up in the red to about 100 lbs. I did not leave the gauge on long to see if that pressure dissapated.

What could be going on? There should have been no reason for the compressor to be recycling every few seconds. I had the doors open and the temperature set at 60°. I have only owned the vehicle for 1 1/2 years and have no way of knowing if it had ever been charged before. Also when the compressor cycled on the gauge would go up to 55, sometimes 58° (still in the green range) which was higher than the chart said it should for the ambient temperature.

AC_Doc on Sat August 15, 2015 10:58 PM

You got the pressure readings operations backwards.
The compressor causes the low side to go DOWN when it turns on, not up.

1)The pressure goes to 15 psi when the compressor cycles ON. This low pressure causes the pressure switch to its job and turn off the compressor.
2) The pressure rises when the compressor cycles OFF until it reaches 55 psi causing the pressure switch to its job again and turn ON the compressor.
3) Repeat steps 1 & 2.

With the system OFF the refrigerant will assume a pressure equal to its ambient temperature at the time. 100 psi is about 90 degrees.

Your system has a leak and is nearly empty of charge.

Locate and fix the leak.
Recharge to factory specifications.

Ac_Doc

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Sometimes you must accept things at faith value!

Cussboy on Sun August 16, 2015 9:40 AM

Quote
Originally posted by: AC_Doc
Locate and fix the leak. Recharge to factory specifications.

Ac_Doc

Above. Let's assume that you find the leak, and fix it. Then you still need a real gauge set and a vacuum pump at minimum. To find the leak you may need UV dye to be added, and a special light/goggles to see it. Bubble solution, looking for oily residue at fittings, and electronic sniffer can help identify leaks, depending on where the leak is.

So are you willing to spend that kind of money and learn AC to fix this?? I say take it to a REAL auto AC shop, not a Brake-O with a sign, and get it fixed right.

And NEVER, EVER add any type of sealant !!!!
And NEVER, EVER add any type of sealant !!!!
And NEVER, EVER add any type of sealant !!!!
And NEVER, EVER add any type of sealant !!!!