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240 I want A/C, help me devise a game plan

Doing AC correctly is rarely quick or cheap.

Exactly. I went thru an 8 month process trying to optimize AC function of my 93 Aerostar 4.0L. Already 134a converted....and condenser replaced when my daughter took a shovel thru the grille. New OEM NOS high/low side hoses, a thorough flush using a $50 flushing tool (your local auto parts sells this tool, add compressed air). Even with proper charge, what finally put my system into proper ops was a new thermostatic clutch fan. If you cannot get the heat OUT of the condenser, your head pressures will run TOO HIGH and you'll blow things apart. It never hurts to clean the condenser which is slathered with bugs and dirt.... that heat must be removed for proper ops. Now I've got 44*F coming out of my center vents.... Oh the JOY :cool:

You could look for the 91-93 front "pusher fan" and retrofit to your system. Check the schematics but I think the power for same comes off the bus right above your battery, the harness snakes thru the grille area and connects to the pressure switch on the high side line LEAVING the condenser but before your freon expansion. Might be there, might not on an 87? Considering my experience, I'd recommend this additional fan, as the OEM fan might not have enough capacity. The TROPICAL clutch fan might be just fine however. Talk to K-jets, the expert on that fan setup.
 
Don't just charge it up with something without knowing what's in there already, you really have to pump it down to a vacuum and then charge so you know how much it has.

I ran propane in the stock AC system on my 240 for a while until the expansion valve eventually failed so that's another option. I'm not going to advise you do this because it's not legal, but I will say that in my own experience it worked quite well. Yes, I know, it's flammable, but so is the gasoline that is running through pressurized lines, I'm just not concerned about 8oz of propane. My system had lost its charge years before and was empty, I pumped it out and charged it with some propane on a whim just to see if it would work and I was pleasantly surprised.
 
Don't just charge it up with something without knowing what's in there already, you really have to pump it down to a vacuum and then charge so you know how much it has.

I ran propane in the stock AC system on my 240 for a while until the expansion valve eventually failed so that's another option. I'm not going to advise you do this because it's not legal, but I will say that in my own experience it worked quite well. Yes, I know, it's flammable, but so is the gasoline that is running through pressurized lines, I'm just not concerned about 8oz of propane. My system had lost its charge years before and was empty, I pumped it out and charged it with some propane on a whim just to see if it would work and I was pleasantly surprised.

Hell, you can even use a can of PC duster to charge an AC system.
I am sure there are lots of gasses that could be used, but neither of you mention viable alternatives. Be kind to the next person that may work on the vehicle. No one is going to know what is in the system unless a chemical test is performed. If you read, OP does not have to worry with what is in there anymore.
 
My 89 had a dead AC system when I bought the car, and according to the previous owner, the AC hadn't worked since the early 2000's. I thought about repairing the old 89 R12 system, but it seemed like every component was bad, including the evaporator. I did it the hard but smart way and bought a complete 93 240 parts car with a factory R134A System and swapped every component in to my 89, including the blower HVAC unit behind the dash. It now blows ice cold, colder then my 98 V70R.

The front mounted fan really helps when sitting in traffic, so on a 1990-older system I would think adding a front fan would really optimize the performance of the AC System.
 
Just wanted to give an update. Everything I said I was going to replace has been replaced. Lines are insulated nicely and the expansion valve was adjusted all the way in and then back out 2.5 turns. Going to take it to get charged on Friday!

After I get it working, I am going to find a way to get the 940 e-fan low setting to cut on with the a/c. The high side is already being used with a temp switch for engine cooling but I would imagine that the low setting would be comparable with the late 240 a/c pusher fans. Not sure how to do this right now however since all of the wiring diagrams I have found have power running to the switching components of the a/c. Perhaps I can hack into the a/c relay somehow?

Thanks again for all of the help, I'll keep you all posted.
 
The relay gets grounded by the computer. I guess you could rig another relay that when the a.c. compressor has power it closes the circuit and grounds the fan relay. Just an idea....


Without reading back, did you do your math on how much oil to put back into the new compressor? (If installed)
 
Hmm, that's a good idea about tapping into the wire that powers the compressor clutch. I'll look into that.

Didn't replace the compressor but for sure did lose some oil when the high side blew. I have read that the newer machines should be able to pull out the old oil when the system is evacuated and then I can get them to put in ester oil. Any truth to that?
 
Hmm, that's a good idea about tapping into the wire that powers the compressor clutch. I'll look into that.

Didn't replace the compressor but for sure did lose some oil when the high side blew. I have read that the newer machines should be able to pull out the old oil when the system is evacuated and then I can get them to put in ester oil. Any truth to that?

The newer machines may be able to FLUSH the system, but they won't "pull out the old oil". It's everywhere - lots of nooks/crannies where it just sits under vacuum. The system will have to be flushed with an appropriate flushing agent to get the old oil out.
 
Didn't replace the compressor but for sure did lose some oil when the high side blew. I have read that the newer machines should be able to pull out the old oil when the system is evacuated and then I can get them to put in ester oil. Any truth to that?

Oil is something which I am still refining my method. It's almost impossible to determine how much oil is left in a system, so you kinda have to guess how much to put back in. Too much and system will be inefficient. Too little and the compressor can fail. Wrong weight isn't good either. Put the wrong oil in a hybrid: electrocution hazard!

I use expensive, $5k+, A.C. machines at the shops I have worked at. I am also certified to handle refrigerant and to do A.C. repairs btw. With these machines i have been trained to put back the same amount of oil that comes out during evacuation. It gets trapped in a small reservoir on the front of the machine. Sometimes I get nothing. Sometimes over an ounce comes out. I generally squirt back at least 0.5 ounces with dye just as my personal method. Is it correct? Its worked fine so far!

Did you replace the drier? Always a good idea if it's in the budget and not too hard to get at.
 
I did replace the drier as well as the high side hose and expansion valve. When that high side hose blew, I lost a good bit of oil. It went everywhere, including leaving an oily spot on my gravel driveway that is still there a week later. Honestly, I guesstimated that I lost about 3 ounces of oil and put that much back in there just so it wouldn't get ran dry when I take it to the shop and they undoubtedly turn the a/c system on before servicing it. I am going to tell them that I have no idea how much oil is in the system and hopefully they know what to do from there.
 
Not sure how to do this right now however since all of the wiring diagrams I have found have power running to the switching components of the a/c. Perhaps I can hack into the a/c relay somehow?

The relay gets grounded by the computer. I guess you could rig another relay that when the a.c. compressor has power it closes the circuit and grounds the fan relay. Just an idea....

Easiest thing in the world. Bosch type 30A relay:

v9oyIxO.jpg


Trigger to clutch wire, output to low speed fan input (may be yel/rd or blu/blk depending on year of donor 940)

p68r3vy.jpg
 
Easiest thing in the world. Bosch type 30A relay:

v9oyIxO.jpg


Trigger to clutch wire, output to low speed fan input (may be yel/rd or blu/blk depending on year of donor 940)

p68r3vy.jpg

Thanks man, that's nice and simple. I'll do it this weekend.

Another tip - keep drier sealed until ready to pull vacuum.

Hmm, too late for that because I have already installed everything. Thanks for the tip though.
 
There's desiccant material in the drier -- absorbs moisture. You don't want it exposed to atmosphere because there's LOTS of moisture in the air. The more moisture it pulls out of the air, the less effective it will be once the system is up and running. So, you can install the dryer - but leave the caps on until it's time to draw a vacuum to minimize the amount of time that the desiccant is exposed to anything but vacuum and freon/lubricant. Right before vacuum pull, remove caps and hook hoses up.

For others - the next time.
 
It has been dropped off at a Volvo specialty shop in Durham, Swedish Imports. I gave them the run down on everything and they know these cars well. Fingers crossed that I pick up a car with working a/c tomorrow afternoon!
 
How bad is re using the original drier? I did it on both cars. On the 86 I snapped a line trying to remove the old one and didn't want to risk it on the other side. On the 88 I got one side loose but I could see that turning the nut on the other side was starting to stretch the metal so I left it alone.
 
How bad is re using the original drier? I did it on both cars. On the 86 I snapped a line trying to remove the old one and didn't want to risk it on the other side. On the 88 I got one side loose but I could see that turning the nut on the other side was starting to stretch the metal so I left it alone.

I think the danger is that an old, moisture laden drier bag can deteriorate/break up and send pieces of it throughout the system. I may be wrong about that-never had it happen to me and i have reused driers before too.
 
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