Retrofitted AC to R134, best way to improve performance?

[Jesda]

Background: 2003 I changed the compressor and pressure switch. 2004 did a flush/recharge with R12 and replaced the dryer. Worked great until the pulley seized in the fall/winter of 2004, the compressor sat dormant, and the R12 leaked out.

Fast forward to yesterday, I paid $286 to retrofit to R134 and do an evac/recharge. Now, the AC works but in a pretty crappy way. Its barely enough with the blower going full speed on an 85-degree day.

Question: What is the next most effective way to improve performance? Replace the dryer, upgrade to a larger condensor, or replace the evaporator? Can I add a second condensor fan?

Thanks

[DAEDALUS]

Replacing the drier is a must for longevity, but it won't do a thing for cooling. Make sure to blow/flush out any dirt and debris around the condenser and radiator.

The AC is a heat pump system, so you would probably have to upgrade everything for an appreciable improvemenet. Bigger compressor to pump more fluid, bigger condenser to cool more fluid, and a new evaporator to flow more fluid. Can't tell you what the weakest link in the chain is right now, but it could easily be that something is not performing as well as it could. If the line leaving the condenser is hot then a second fan might help if you can figure out where to put it and how best to wire it in. Consider loads, wire ratings, and the impact to the alternator's and/or battery's life.

Did you get a rebuilt variable displacement OEM compressor designed for R134a installed? How about the hoses, did they replace those too?

[Jesda]

Same hoses. OEM compressor from a 91 Q45.

I assume I could just yank these components (condensor, compressor) from a 94 Q?

[DAEDALUS]

I don't know for sure that all the lines and everything will bolt up, but you'll want the hoses too. R134a leaks through R12 hoses. 1993 should work too--R134a was mandatory then.

[elwesso]

Id think itd be easier to just get some R12 on ebay?

[DominickJ30]

The dryer should have been replaced with the retrofit. Also they should have changed the oil in the system. Was there a leak in the system or what? What was the reason for the retrofit?

[Jesda]

Yes, there was a leak. Dye was added. Oil was also changed. When funds become available, next thing will be a dryer replacement.

I dont know what the expansion valve is, but should I replace that? The AC worked perfectly with R12.

[DAEDALUS]

Expansion valve controls the flow into the evaporator--I assumed both would be replaced at the same time. Not sure if flow is limited by the valve or the compressor. Again, it's a system--the 2 were designed for each other. To begin replacing parts in the hunt for higher BTUs, we're likely talking so much cost at this point that keeping it R-12 and fixing the leak would seem cheap. AC conversion is IMO one of the harder things to do right, and I could never get myself to trust anyone locally that I've found so far (doesn't say much, I don't trust the local boneheads much period, though I haven't looked in years). You won't know if they did it wrong until after the warranty expires. There's a lot more to it than just changing the oil. System has to be flushed well, and the flush has to be removed.

[maxnix]

When funds become available, next thing will be a dryer replacement.

The dryer had to be replaced because it is contaminated with R12.

[DominickJ30]

The dryer had to be replaced because it is contaminated with R12.

Not R12, Mineral Oil. Unless they drained it?

Jesda do you know what kind of oil they put in?

[Jesda]

Humidity creeped up today. This retrofit is complete crap. I'm getting my money back tomorrow.

[DominickJ30]

Humidity creeped up today. This retrofit is complete crap. I'm getting my money back tomorrow.

Maybe it all leaked out already?

[Jesda]

So, freeze12 worked beautifully. The dye that Midas added last time didnt show up anywhere, so there's no apparent leaks.

Unfortunately, I forgot to add oil. Compressor seized. Whee! I did have fun learning about air conditioning throughout the process.

Q for sale.

[911/Q45]

Jesda, you remind me of myself 35 years ago!