Year: 2000
Make: Ford
Model: Excursion
Engine Size: V10
Refrigerant Type: R134A
Ambient Temp: 100
Pressure Low: 55
Pressure High: 300
Country of Origin: United States
Hello All,
I have just performed what should have been a very simple job on a customers Excursion. Below is the history of events as they occurred.
Vehicle brought to me stating it had been to two different shops and neither could find a leak. The system had starting blowing hot the prior summer and the owner didn't have the funds to get the repair shop. Bottom line they couldn't find the leak. they added oil and dye and charged it and it lasted about one month. So there's a small leak. I pulled out the black light and found a leak at the compressor seal. No big deal , right. The owner needed to take the vehicle on a trip so I charged it with 3.5 lbs it was blowing a chilly 40 degrees at the vent. So the vehicle returns, I evacuate, remove the original compressor and install a new one, a new accumulator and orifice tube. I pump the system down for 1 hour, leave the gauges on overnight and come back the next morning. I found a nice tight system charge with 3.5 lbs just like before and I'm only getting about 60 degrees at the vent. I suspect an issue with the new orifice tube so I remove it and everything looks normal. I had installed an extreme service tube for climates over 105 degrees (yuma) . I picked up a stock orifice tube. installed it and charged it again. Same issue. I then noticed the high gauge needle was vibrating and I could feel it in the line. Seems like I recalled that having to do with the check valves in the compressor. I install another new compressor and get the same result.
So, I'm not sure what to do here. I'm asking for ideas on why one day I'm getting 40 degrees and the next not?
Ideas?
too much oil.
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I do not like to see the high side pulsate. Are you using NEW (not remanned) compressors? I hope you're not using a variable orfice tube either. Make sure you're not getting a reheat from the heater core. Also, mist the condenser with a hose just to make sure the condenser is working correctly. Also, when you do this, see if the pulsating stops. Are you using a reputable brand of R134a? There is some bogus stuff out there.
Pressures seem a little high, but not super high for the temp. Was the condenser or fan shroud removed? There might not be enough air flow across the condenser. Spray it with some water and see what happens. Does it have rear air? How was the charge of 3.5 pounds of refrigerant determined? The spec sheet does not list 3.5 pounds (3.5*16=56 ounces) for any excursion. It may be over charged. More refrigerant does not do any good with a properly functioning system. Just a few ideas.
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I bought a can of 134a at w**-mart that had a stop leak, oil, and dye in it. It also had a hose and a gauge, so now I'm an AC pro!
And that is why I asked about the amount. Always go with the sticker under the hood when it is there. I always use the OT that is called for, never a different/sever service/adjustable one. Too many stories about having to go back and change them latter. If the fan clutch is bad, it is not getting the air flow it needs. It could work ok one day and not the next due to slight temperature and humidity differences.
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I bought a can of 134a at w**-mart that had a stop leak, oil, and dye in it. It also had a hose and a gauge, so now I'm an AC pro!
A 2000 model year with an unknown history - well, a documented history of deferred maintenance? Flushing back to bare metal would be a good first step.
That vehicle came with an FS10 compressor & a 6mm condenser. The other shop added oil. Probably some magic in a can someplace along the 14 years it has been on the road too.
Are those pressures at idle? If so what are the pressures @ 1500 rpm?
Both doors open, cabin fan(s) on highest speed?
Could be way too much oil, or the remnants of an FS10 in the condenser.
.
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"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.
The compressor was the original to the best of the owners knowledge. It was previously owned by his parents. The oil was transparent the original orifice tube was not indicitive of a black death situation had either been the case I would have recommended a condenser replacement. Remember, the a/c worked perfectly with the exception of a small leak at the compressor seal. I measured the oil out of the accumulator and the compressor and added that plus2 oz. The pressure at1500 rpm was slightly higher on the high side and slightly lower on the low side. I don't recall exactly but in the neighborhood of 50 on the low and 315 on the high. The test was performed with both front/back fans on high and doors open. Thanks for your questions bohica, any more thoughts?
I only install new compressors, learned my lesson on that. I did check the vacuum lines to the heater controls as they are in the area I was working. All lines were connected and had good vacuum. I had installed a variable orifice but removed it first suspecting that to be the cause. I will try replacing the fan clutch next. It does not have any more resistance when hot than when ambient.
I will mist the condenser tonight and as for the R134 I get it at Sam's same as always. I was thinking about that too but the first charge was on the end of my last tank and I just bought a new tank. Can't recall the brand but it's the same I've been using for years.
So my customer needed to pick up his rig last night and I wasn't there at the time. He was thrilled with 40 degrees at the vent. Now I'm very confused. Has anyone seen this happen before?
I thought about that too. I have a whole house swamp cooler that I put in front of the grill and still never got close to 40. I also took it on couple mile drive and same result, around 50 degrees. It'll be back I'm sure.
I realize this is an old thread but Im still battling the same issues that you posted. Any solutions to this issue? AC in my Excursion works pretty good as long as the sun isnt hitting the truck. It could be 100F and sunny and the AC vent temp will be 60F+ but as soon as the sun goes down and still 100F the vent temps will drop down to low 50s. Also was reading that dual air systems tend to have higher low side pressure, is this typical?
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