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

J_Jones

Active member
Joined
May 1, 2005
Location
Lincolnton, NC
1987 240 with original a/c system. Has (1) recently added port on the back of the compressor which I am assuming is an r-134 port. I poked the needle valve with my finger and there is pressure in there + some neon green stuff. I replaced some crappy wiring and the thermostat switch with capillary tube and the a/c now cuts on when I turn it from 0 > results in no cold air but no crazy noises either.

I have no idea what I am doing and seeking guidance. I am considering ordering either an r12 alternative redtek or duracool kit to try and charge it. I know Impvolvo has some red/blue a/c lines that he said I could use to charge it as well if I got the stuff.

On the flip side, a shop said that they could charge it with r134 for ~$180.

Since there is pressure in there, I am assuming it is not leaking.

That's where I am at. I completely new to messing with A/C systems but this is the fiance's vehicle and it needs to work.

Suggestions and guidance are greatly appreciated.
 
Since there is pressure in there, I am assuming it is not leaking.

All pressure indicates is that some portion of whatever was in there is still in there. Doesn't mean that it doesn't have a leak somewhere. The neon green stuff is usually leak detector.
 
All pressure indicates is that some portion of whatever was in there is still in there. Doesn't mean that it doesn't have a leak somewhere. The neon green stuff is usually leak detector.

Good to know. I've seen that you have posted in quite a few a/c threads and know a lot about them. Would you suggest going to a shop and getting the system drained and set on vacuum to assess for leaks? Should I replace all seals first?
 
Seeing as how it doesn't have a complete charge; it would be safer to take it to a shop and have it evacuated and put under a vacuum to show any leaks if they're there. If it checks out, then you can go into recharging.
 
We would often add the dye because pulling a vacuum may not show the leak as well as working pressures with dye. If it were me, I would add a bit until the proper pressures are met on the gauge versus the ambient conditions. This is if you feel comfortable doing it. This would be the least expensive route to see if it will kick on, let it run, and black light the system.
Now that said, a lot of DIY refrigerant has dye in it too. Either way, something was added to the system for a reason. Finding the leak before paying a shop to put r134a in it would be prudent.
 
Isn't the PAG oil green?

PAG by itself is basically just mineral oil to the extent of my knowledge and is typically clear or slightly yellow.

Green tinted PAG oil is usually the stuff with UV dye included in it. A lot of over-the-parts-counter A/C products come with some manner of UV dye in them to make leak detection easier for home mechanics. Some of the most common R-134a cans I see sold at my work are the ones that are "all-in-one" refrigerant, oil and dye together.
 
Yeah, I'd charge it up to proper pressure and see what happens. Use a black light at night to check for leaks.
 
Thanks to everyone for their input.

Seems like the majority consensus is to charge it, see if it works, and look for leaks. I think that this is a good plan. If you think about it, I could go get it drained and then filled for ~$200 only to have it leak and be out that amount. On the other hand, if I charge it myself and it leaks I am only out about ~$30. I would then have to fix the leaks and then go get it drained and refilled, hopefully problem solved.

Now as far as charging it, should I grab one of the r134 cans from the auto stores or something that is r12a/r134 like redtex or duracool? I have no idea what is currently in the system. One would assume that since the r134 conversion fitting is on the back of the compressor that the system was fully drained and then filled with r134, but perhaps not. Might be a mix of both in there.
 
1) Fill with 134 if it holds pressure (use black light if it had leak dye in it) OR give it to shop to test pressure properly
2) Drain all freon and vacuum whole system and fill with r12+easter oil at the proper AC shop
3) Enjoy
Recently restored 10+ years old non working R12 system in my brick
 
R12 gives best performance but it's also the most expensive. If you fill with R134 make sure there's ester in the system, which it should if it was converted. I used Envirosafe (One of many r12/r134 replacements) which is supposedly better than using R134 in an R12 system. Paid ~$30 for a set of 3 cans with an oil charge and stop leak. (Probably not a good idea to use the stop leak.) So far so good. The system in my '88 takes 2.5 of the 6oz cans.
 
I have always vacuumed and added PAG 46 UV oil. I've got it a little easier having a refrigerant machine. You may need to add a little LESS 134 than the R-12 capacity to get the pressures right. I have also cranked the expansion valve down a few turns.
 
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1) Fill with 134 if it holds pressure (use black light if it had leak dye in it) OR give it to shop to test pressure properly
2) Drain all freon and vacuum whole system and fill with r12+easter oil at the proper AC shop
3) Enjoy
Recently restored 10+ years old non working R12 system in my brick
In the shops I ran, if there was a gross leak the cause could typically be found. However, if it was down only a small amount dye was added, charged,and the customer was sent on their way to return in a few days to black light. The dye shows ALL the leaks. It gets very expensive paying flat rate to have a tech run the sniffer over every bit, and even then false readings occur or not detected at all.
I have always vacuumed and added PAG 46 UV oil. I've got it a little easier having a refrigerant machine. You may need to add a little more 134 than the R-12 capacity to get the pressures right. I have also cranked the expansion valve down a few turns.
Nice to have a machine at your disposal! Please do tell of this expansion valve modification. Any different pressure readings or do you shoot for a certain change in temperature?
 
The hell? 200$ for an R134 charge is normal over the pond?
Here it's 50 flat rate on any vehicle in standard shops, except R12 that you need to know a guy that knows a guy that still has that lying around to overcharge you.
 
Nice to have a machine at your disposal! Please do tell of this expansion valve modification. Any different pressure readings or do you shoot for a certain change in temperature?

On the expansion valve, there is an Allen fitting inside the bottom of the valve. I usually turn it in 1.5 to 2 turns. That raises the pressure slightly. It will take a little LESS R134 if you do this (I said more before but I was wrongo). I would also suggest changing out oils for PAG 46 oil. This puts low side pressure around 35-40psi and high side around 150-200psi.
 
On the expansion valve, there is an Allen fitting inside the bottom of the valve. I usually turn it in 1.5 to 2 turns. That raises the pressure slightly. It will take a little LESS R134 if you do this (I said more before but I was wrongo). I would also suggest changing out oils for PAG 46 oil. This puts low side pressure around 35-40psi and high side around 150-200psi.

I don't remember where I learned this trick and yes it does help. I turn it all the way in then back out 2 turns. Probably ends up at the same setting. One of my Volvo owners also bought a new 911 and complained about poor a/c. Dealer said it was as good as it gets. Being we helped his 242 he said do the 911. Tremendous help. He went back too the dealer and showed him the improvement. Not many days later I get a call from a engineer at Porsch wanting to know what I had done. He was firm in saying the expansion valve was not adjustable. I ask him if he had ever looked at one? He hung up on me. Soon the word got around to the local Porsche club and we did lots of up grades.
 
Update: I charged it with r134, had working a/c for 3 glorious minutes...and then the high side hose blew. That was scary, huge cloud of stuff and green goo everywhere. It was the stock high side hose with muffler on it that goes in front of the condenser. Now determined, I have just received a new four seasons high side hose (no muffler on this one), drier, and expansion valve; waiting on the complete seal kit to get here. Once I have everything in hand, going to go thru and replace those parts as well as every seal.

Few questions:
1. Any lube for the o-rings or install dry?
2. Can't find any shops that will/can do r12 so will be going with r134. I plan to find a happy medium between 1.5-2 turns in and all the way in with 2 turns out. Any other input on this?
3. Since I released the refrigerant and green goo, looks like I need to take it to the shop for vacuuming and then adding of the proper lubricant and refrigerant amounts. Correct thinking?

Thanks for all of the help, almost there!
 
Update: I charged it with r134, had working a/c for 3 glorious minutes...and then the high side hose blew. That was scary, huge cloud of stuff and green goo everywhere. It was the stock high side hose with muffler on it that goes in front of the condenser. Now determined, I have just received a new four seasons high side hose (no muffler on this one), drier, and expansion valve; waiting on the complete seal kit to get here. Once I have everything in hand, going to go thru and replace those parts as well as every seal.
Man. That stinks. Sorry to hear that, but at least the compressor is working!
Few questions:
1. Any lube for the o-rings or install dry?
Use a little oil of the same type that will be put in the recharge. R134a will be ester or PAG-no mineral oil!
2. Can't find any shops that will/can do r12 so will be going with r134. I plan to find a happy medium between 1.5-2 turns in and all the way in with 2 turns out. Any other input on this?
See above. This is new info to me too. Will give it a try myself though.
3. Since I released the refrigerant and green goo, looks like I need to take it to the shop for vacuuming and then adding of the proper lubricant and refrigerant amounts. Correct thinking?
Absolutely a vacuum. If you really want to do it correctly, you will flush all of the components- compressor, condenser, and evap core. Will take some effort, but ensures whatever was in there before does not contaminate your new stuff.

Thanks for all of the help, almost there!

Doing AC correctly is rarely quick or cheap. Sounds like you are willing to put in the effort though.
 
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