I Charged My AC System Today....Help!!

Okay

Last week I noticed that my air conditioner was putting out barely cool air. So I says to myself, "It must just need a charge." Today I dug out the manifold and gauges. Sure enough it only had about 150 lb on the high side , so I proceeded to add the modern marvel 134a. It took about a can and a half.

The pressure reading at 1200 rpm is 45 / 225. From what I've read that's normal. However, the high side gauge pulses rapidly and if you touch the hose you can feel the corresponding pounding of the compressor. No noise from the compressor though.

Is this normal on an 03 Explorer? Did I put too much refrigerant in it? Or is it an indication of something else wrong? It's making a lot of cold air. Should I mention that the ambient temp was only 80F today? I know that affects things but I don't remember how.

Steve

I may be wrong but I think the pressure is a little high for the temp of the day from what I recall. Is the clutch kicking in and out or does it get warm at high way speeds (55 to 70MPH) then I would say it has too much and the high pressure switch is kicking it off.

my 04 does the same thing, i added some to mine this past weekend at 85 degrees and the high side gauge was pulsating like crazy. you could feel it in the line also. to get a good reading i closed the valve and check the trapped pressure it was about 235-240 and 42 low side. low side was steady.

Thanks for the quick responses.

It's supposed to get up into the 90s today. If I get time, I'm going to reconnect the gauges and test it again. I have limited experience with AC systems. I just successfully retrofitted my 90 Saab over to 134a. I dismantled the entire system and thoroughly flushed each component, except the compressor of course. It turned out super good w/lots of cold air. Before that, I'd never even charged a system. But I do have the Ford factory service manual and if I'm interpreting the graphs correctly, at 80 F normal low/high pressures are 30/185 on the low end of the normal range to 58/270 on the high end of normal pressures. So based on that JMorristn and I are both within specs. However, I'm pretty certain that this rapid pulsing on the high side is not normal. Somebody knows the answer. I'll post it if I find it.

All I can tell you is mine does this as-well, and has gotten worse I can feel it in the steering wheel I am thinking a will be needed a new compressor soon.

Your levels seem kind of high to be honest for ambient temp of 80.. Your high pressure should be 2.2-2.5x the ambient temperature.. So basically 176-200 psi at 1500 RPM with AC on the highest setting, low pressure should hover around 25-30.. It should never reach 225 PSI on the high side or 45 on the low side. Did you by chance pull a vacuum before recharging the system?

Blee1099 said:

Your levels seem kind of high to be honest for ambient temp of 80.. Your high pressure should be 2.2-2.5x the ambient temperature.. So basically 176-200 psi at 1500 RPM with AC on the highest setting, low pressure should hover around 25-30.. It should never reach 225 PSI on the high side or 45 on the low side. Did you by chance pull a vacuum before recharging the system?

Click to expand...

I think you're right. I added too much refrigerant.

I didn't pull a vacuum because the system still had 150 psi on the high side and was making a small amount of cold air. My understanding is that unless the system is compromised by opening it to the atmosphere (changing a component or major leak) evacuation isn't necessary. Is that right?

I'm going to bleed off some of the refrigerant. Let's see...billions of dollars have been spent by the automotive industry and passed on to the consumer to change over to 134a because it's not harmful to the environment right?

you are correct

Regarding the rapidly fluctuating reading on the high side pressure gauge, I found this in the Ford Factory Manual:

NOTE: Vehicles equipped with Visteon fixed scroll A/C compressors may experience rapid refrigerant high side pressure fluctuations upon cold startups and/or after refrigerant system recharges. These high side refrigerant fluctuations are characteristic of the Visteon fixed scroll compressor and not an indication of a failing/failed A/C compressor.

The Visteon SC115 A/C compressor has the following characteristics:
• Tangential mount design—three lugs.
• The single manifold block of the compressor manifold and tube assembly fits to the suction and discharge ports. Two O-ring seals are used for sealing.
• An eccentric bushing is driven by the shaft of the A/C compressor.
• An orbiting scroll driven by the eccentric bushing compresses the refrigerant gas against the walls of the fixed scroll.
• Single reed-type discharge valve mounted on the back of the fixed scroll. There are no suction valves.
• Non-serviceable shaft seal fully supported on both sides by bearings.
• The A/C compressor uses PAG oil or equivalent. This oil contains special additives required for the A/C compressor.
• The A/C compressor oil from vehicles equipped with an Visteon SC115 A/C compressor may have some slightly dark-colored streaks while maintaining normal oil viscosity. This is normal for this A/C compressor because of break-in wear of the scroll seals that can discolor the oil.
• Use standard oil matching procedures when installing new compressors.

So, apparently the rapid fluctuations are normal after charging a system with the Visteon compressor. I haven't checked yet to confirm that's the compressor I have, but I'd bet on it.

Tomorrow I'm going to tinker with it some more. I'm hoping that when I put the gauges on tomorrow that the system is stablelized and I can get an accurate high side reading. I was using the center of the fluctuation sweep to determine my reading. But the high end of the fluctuation may be the actual pressure.

Please post procedure for R-134a recharge

Blee1099 said:

Your levels seem kind of high to be honest for ambient temp of 80.. Your high pressure should be 2.2-2.5x the ambient temperature.. So basically 176-200 psi at 1500 RPM with AC on the highest setting, low pressure should hover around 25-30.. It should never reach 225 PSI on the high side or 45 on the low side. Did you by chance pull a vacuum before recharging the system?

Click to expand...

My AC fails to cool on the 11 year old Explorer XLT. What is the procedure for recharging? I presume the low side is the fitting by the radiator and the high side is the compressor reservoir side.

Blend door Actuator Issue

Well, I removed the four screws securing the AC module to the dash and cleaned the 11 years of Central Oregon dirt from the rear. In the process, I remembered that the Exploder service guy mentioned the blend door, and that is why his tech lashed the door closed in summer season, requiring my opening in the winter season. What can be done to repair this blend door actuator? I figure that the variable temp control in the center of the module controls the degree to which the door opens, ie. the amount of hot air. Somehow, when AC Max was selected, the door stayed closed by itself.

I am recharging the system this afternoon and will run AC Max until resolving gthe blend door actuator issue.