The pressure gauge will not yell you if the system is overcharged or undercharged. It will also not tell you how much compressor oil is in the system. r134a kits have 2oz of compressor oil included in the refrigerant.

 

You cannot flush a parallel path condenser or evap core and know you have it flushed. The filter/reciever/drier will provide some filtration after the condenser. What is the micron retention?

If your compressor didnt fail, only clutch or something, then its easy enough to just replace a compressor/clutch assembly.

I have flushed 20 gal thru, and still had a few flakes of particulate coming out of just an evap core. One path can be plugged with debris, and the others open. Or all the flow goes thru the closest, and less thru the farthest.

Some sketchy shop might do this, but Id insist on a filter on the suction of the new compressor. On a well flushed system, its unlikely to plug it off and youll get by. But honestly, theres no way of knowing if it is ever well flushed if a compressor has failed. When you get the black death, you replace everything typically. the oil turns black with microfine metal debris.

In years gone by, up to early 90s, the evap and condenser were serpentine, one path thru winding back and forth, and they could be very effectively flushed. When they started using more efficient parallel path designs , and making them out of aluminum to be smaller and lighter and more fuel efficient, that ability was basically lost. First time I rebuilt my 89 toyota,(had it 23 yrs, it got rebuilt a couple times, once due to just sitting till compressor seals leaked) I put in a larger serpentine condenser so it would never need to be replaced again and could be flushed. Original Denso compressor lasted 20 yrs till that happened.

But, if they are willing to warrant it to you for 2 yrs, then you may not have a lot to lose. Except that rebuilding systems every couple yrs is expensive and sucks.

A leading cause of failure is leak in evap core. Why? well pressure fluctuations from kicking on/off can fatigue the very thin aluminum is one way. But in some vehicles, it is prone to failure because cabin dirt accumulates on the fins because there is no filter and air intake is by passenger feet in place that gets dust when on recirc.. condensate soaks into this dirt. Corrosion takes place between minerals/organic material in the dirt and aluminum when waters present. Presto ...pinhole somewhere and a leak after a few yrs.

 

I'm going to go ahead and follow this thread. I've owned my truck for 6 years and never had a problem until this summer with the AC. I run AC out of the vents 10/12 months in the year and it seems as if my compressor clutch isn't engaging enough.

Sometimes it will blow cold, then I'll stomp on it at a red light and it'll start to blow extremely cold, and stay cold. Sometimes it stays cold for minutes, sometimes for days. When I have the AC on, I've looked under the hood and watched for over 10 minutes and the clutch never engaged. I'll go drive around and come back and it still won't be engaged, obviously blowing warm the whole drive. Once I go stomp on it and come back after I get it to blow cold, I'll open the hood and see the clutch is engaged. I guess 15 years of age and ~100 days caught up to my compressor clutch.

EDIT: After looking at compressors, there's only a $120 difference between a Murray compressor and the OEM Motorcraft compressor, so I'll probably save up the extra money and go with the Motorcraft one.

 

Do you have a better idea how to remove the compressor oil without flushing the system?

Compressor oil = Refrigerant Oil
R134a = Refrigerant

F150 refrigerant oil should be 9oz in weight. PAG oils is more hydrographic than brake fluid. It's almost impossible to boil off moisture absorbed by the oil using a vacuum pump.

 

FWIW, I have had a 4 Seasons on my truck for about three years now and it's working fine.

 

You just need to remove the spacer or washer inside the compresor hub until the gap is 0.014-0.033". A new compressor have 3 spacer/washer.

Your problem is a faulty Fan clutch. Most Motorcraft Parts sold online are COUNTERFEIT.

How do I know if a part is counterfeit?
Unfortunately, our high quality breeds a lot of imitation. Every Ford Part is stamped with the Blue Oval or Motorcraft® brand so that you know it’s authentic. If a part you received does not have one of those stamps, then it’s not a Ford Part.

 

The system was leaking from the hose, and from the accumulator. The front seal on the compressor was also leaking. I've had to add PAG to it a couple of times, so I knew that seal was taking a dump anyway. I am keeping the old compressor because the clutch still works fine.... plus I wouldn't mind poking around inside.

They do filter everything at the place I took it to, thanks for the suggestion. He did make it a point to tell me that before I could even ask. Also, using one of their compressors gives a 2 year warranty on everything vs. a 1 year Motorcraft.

 

If the compressor didnt fail, you usually dont remove the oil. Its known how much oil accumulates where in the system. You replace the needed parts and add the oil to that part. For example, evap core may hold 2 oz oil, so you add 2 oz oil to it when installing it.

I wouldnt say its impossible to remove residual moisture by pulling vacuum. Depends on ambient temperature and how long you do it for sure. Ive always pulled full vaccuum for 12 hrs or so, before testing for the same time on my own vehicles. Some shops...do vac /test for 30 min . Time is money.

The dessicant in the receiver /drier will remove residual moisture too. Thats why its always replaced. It does that as moisure permeates into the system thru diffusion thru seals. Diffusion occurs due to concentration difference. The pressure doesnt matter. Theres moisture outside, theres no moisture inside, theres a seal with some very limited permeability, entropy does its thing. Very small rate though.

 

These guys are pulling vacuum for 3 to 4 hours. He called about 3 hours ago and told me they were almost done putting it back together. I was at Costco when he called me, and I couldn't hear too terribly well... but I believe he said they are now doing the condenser. I will have it back in about 2 more hours.

It's a happening shop though, they are always busy as hell. They do good work. It's an independently owned Big O.

 

9oz in volume Not weight..

When Refrigerant is recovered some oil is flowing out of the system. When the refrigerant leaks out oil also leaks out. Ford have a specific procedure to follow. If you put too much oil the compressor aill not fail but it will not blow cold airl