Hey everyone, it's been a while since I posted here. The weather is getting warmer, and I can't put off doing the A/C repair that I promised to do any longer.

So, the compressor is not working in the car. It is still running r12. What's the easiest way to get this system up and going if I'm going to replace the compressor anyway. I was thinking I could replace the compressor myself after having the system safely evacuated. Should I convert to r134? Stick with r12 (the price of r12 seems reasonable these days. With everyone using r134 I think the demand for it has really dropped off).

Anyone got a compressor they want to get rid of? I'm looking for one and am in Philadelphia, PA.

Here's my (probably oversimplified) gameplan.

1. Evacuate system
2. Replace compressor
3. Flush components
4. Vacuum
5. Refill (I'm planning on r12 refill so I don't have to replace as much)

Would that work?

 

The way I approach these situations is like this:
First, is there a leak, and in most cases it is a leak that caused the system not to function, find the leak.
Second, the compressor. If it is inop, it must be changed, and there are plenty remanufactured/rebuilt ones for these cars for around $100-150.
Once the system is leak free and has a working compressor, then you can decide on the refrigerant. R12 is expensive and illegal to handle for the DIY guy, so a 134 conversion is probably the way to go. The "new" compressor kits usually contains all the parts for the conversion (providing you got a new compressor), so you have to change the rubber seals and evacuate the system before refilling it with 134.

If the old compressor is OK, and there are no leaks, an option is to use a refrigerant called FREEZE12 which is designed to work with either R12 or R134 systems. Freeze12 is available online, not sold in stores at least not on the West Coast. You can added to your system, and you are done.

I know guys that just fill an R12 system with R134 without any seal change and claim it is OK--not totally scientific but a way to go for a short term and inexpensive solution...
Or you can always go to an A/C shop and spend $1,000 to have the air fixed by the experts...

 

You first need to find out if you have any freon in the system. Get a set of AC gages and check. If no freon then you need to check for a leak. You can also check the compressor by hot wiring it to see if the clutch engages. If you have no freon (0 pressure) then you still have to replace the receiver/dryer and the orifice valve. Check the hoses and condenser for damage/leaks and replace as necessary. Once all checks are done vacuum down the system for 1 hour and check for leaks. At this point you can decide to either go for R12 or 134A. By the way a new compressor comes with compatible oil for either R12 or 134A. As a quick inspection look for oil film around the AC system and compressor. Good luck

 

if the system has been leaky and uncharged for some time, odds are the dryer/reciever is toast, and needs replacing too. I would run some sort of flush through the system to remove any traces of the old AC oil before recharging with new AC oil and R134a (after a thorough leak-down test, of course).

 

So it is holding pressure. Or it was when the compressor was diagnosed by a shop as being dead. Interestingly, It went to the shop providing weak cooling, and whatever they did killed the compressor. It came home not working one bit (maybe they just evacuated the system for the r-12 and figured I would "fix" the compressor while I was at it???) Anyway, I was told that the problem was bigger than just having a freon leak. I'm assuming that the problem is the compressor due to the "weak" AC to failed AC symptoms.

Does the 88 245 have an orifice tube or an expansion valve? It seems it has an expansion valve. Does that also need to be replaced?

 

the classic volvo R12->r134a conversion kit included a new orifice tube, a new reciever/dryer, and all new O'rings for the system.

 

You are wise to stick with R-12, the refrigerant your system was originally designed for.
Volvo A/C systems are barely adequate as it is, (Although they probably work fine in Sweden) and everything else being equal - that means no other changes to the system - you will get about 20% better cooling with R-12. You are also correct in that the price is coming down, as most people have bought into the R134 conversion hype and the cars that use R12 are becoming more and more scarce.

One of the main reasons not to convert is that, to do it right, you absolutely need to replace not just seals but all of the hoses. R134 molecules are smaller than R12, and if you just charge your system with R134 it will seep out through the hoses. Systems designed for R134 use barrier hoses, which have an inner lining to prevent this. And, yes, if you use these hoses with R-12, your system will be virtually leakproof.

R12 systems normally use mineral oil as a lubricant, but can use PAG oil, or Ester oil, with no problems. I have converted a number of cars back to R12 to get improved cooling and one of the benefits is not having to flush the system to get the old oil out. If you have an R12 system, and want to go the other way, to R134, you definitely need to flush out the mineral oil, which will not circulate properly with R134.

Overall, R12 is as close to perfection as an automotive refrigerant can get. The only thing wrong with it is that the greenies don't like it and since it is no longer produced the price has gone up. R134 is a very good substitute that works very well in systems that were designed for it. These systems operate at different pressures than R12, and require larger condensers, evaporators, etc.

Interestingly, R134 is now under attack in Europe and is no longer politically correct. It would probably not be a bad idea to stock up now..

 

R134 has turned out to be nearly as bad a greenhouse gas as R12, but there's a couple R134 replacements in the works that have virtually the same specs, like HFO-1234yf, so no changes are needed, just evacuate and recharge.

 

Don't know Pa. law but in NY you can't get R12 anymore. It is outlawed and most if not all AC places will not handle it. Even the salvage yards don't recover it anymore. It is also illegal to ship into NY even from ebay sellers. It is the best for cooling these old cars but unfortunately not obtainable. I hear from the Tx people that they still have ability to get it . I did a complete conversion on our 89 740 and it works pretty good in our NY temps. I replaced everything except the evap.

 

Decided I'm going with Duracool.

Perry's Auto Parts: Duracool

BUT, I'm still worried about the compressor. I jumped it today, and it turned on. I think that it still works, weakly. BUT I think that the valve in the back of the compressor somehow got JACKED. A while ago, I decided to just convert the car to r134, there was nothing left in the system so I was just going to get the fittings and throw some r134 in and see what happened. Well, nothing would go into the system. As soon as I hit the trigger on the can of r134, the pressure would JUMP to the red zone (can't remember the exact pressure but WAY to high) then slowly drop down to previous pressure which was near zero. It was like the compressor was NOT letting any r134 into the system. Really wish there was another way to get freon into the system.

I think that something is clogged somewhere, probably at the valve that lets r134 into the compressor.

I'll be replacing the drier/accumulator and the expansion valve this week. Maybe one of those were clogged???

Any thoughts? Could it just be the low side port valve is stuck and the gauge is reading the pressure of the can which has been discharged into the hose?

 

Another question. i thought I read somewhere that someone added a low-side service port to a low side hose on their system while the system was evacuated. THAT WOULD BE SO AWESOME!!!!! Has anyone done that, or attempted it, or is there a reason not to do this?