DarkHalo

Has anyone done this? Is there a kit available with all the parts? The compressor went out on my '91 recently and I was thinking it makes sense to do the conversion at the same time. Thoughts?

Scoob

I had my system converted last fall. I needed a new compressor and a few new lines anyway so I had my mechanic do the conversion. Worked like a charm.

87vette

Yeah I had mine done and the good thing about it was I didn't have to pay for anything :D

Topless87

The drier needs to be replaced too(about $90). And, don't panic when the R134 starts blowing warm in a couple years. According to the shop here, I had no leaks, just over time the system is more sensative to small drops in pressure. Recharged and no problems!

scorp508

Which part is the drier? Is it the thermos looking thing?

Lets say I have a brand new condensor, new drier, new orifice tube, but the old lines and compressor. Is dropping the $35 autozone retrofit kit in a waste of time instead of dumping $250 on a R12 recharge? :)

Strick

Here's where having your son go to tech school comes in handy. We were talking about the change over to 134 and there are two ways to do it, one the cheap way (short term results) and the right way (best and long term results.

Firsty of all, if it's working, don't mess with it. Believe it or not, when people check their systems, the schrader (sp) valves are more likely to leak after they are disturbed.

The best way to change over is to replace as many of the components as you can. Be sure to evacuate the system completely. There was a debate going on about the hoses in R-12 systems being too porous for the R-134, but I'm not sure where that stands right now.

scorp508

Hmm... my brother goes to a tech school. I should see if he has an AC class coming up and they can use my car as a patient. :D

Reason I ask is that my AC system is 100% empty of R12 right now. I had a rock go through my condensor. I replaced the condensor and the drier (if its the thermos looking thing). Its a pain to get an R12 charge appointment I can get to right now and if the $35 R134a kit could get me by for a couple of months and then switch back to the R12 fittings I'd do it.

VetteNoob

I know some of the forum AC professionals will offer their suggestion/opinions. Im not one, but here is my experience.

It's doable and relatively affordable. Did mine last year with the help of 85WhiteZ51. FWIW, it's still working after 12 months and a winter of no-use. Here is the list of all I replaced.

Compressor - $100 AZ Factory Air rebuild (Mine was dead anyways)
Orifice tube - $5 Jeff Kopp
Accumulator/Dryer - $50 Jeff Kopp
ALL Sharder valves - $10 AZ
PAG oil - $10
AC pressure switches $40 (just to make sure they weren't defective)
Bad blower motor ground and replaced bad heater control module - $250 (Austin Corvettes)

There was little to no R12 left in the system so that wasnt an issue. Primed the compressor with PAG as instructed. Filled the Dryer/Accumulator with PAG as instructed. Closed up the system and had a mechanic pull a vacuum and fill the R134a for $80.

Only thing else I wish I had replaced was my condensor. My stock condensor is sorta chewed up from road debris so it doesnt cool real well and when sitting with the AC on in 100* traffic the temp climbs to 228*F (not really an issue).

Works great. I no longer sweat while Im driving in 100* heat. I was quoted $1000-$1500 for the conversion from a local shop, I passed and did most of it myself for far less.

Strick

[QUOTE]Hmm... my brother goes to a tech school. I should see if he has an AC class coming up and they can use my car as a patient. :D
[QUOTE]

My son has used his car as a patient and they did great work. I'm getting ready to display my Vette there to show how an electric water pump helps. Lots of bennies available. Next semester, my son has differentials and transmissions. I'm going to see if I can have 410s put in mine. The teachers are super. That's the key. And they have all the tools!

I knew there was a hazard going 140 plus........................the condensor. :yesnod:

383LPE

pull a good vacuum, like -30 microns! seal the system and let it set overnight and make sure it holds, then charge it.

DiabolicalDave

I just had this done earlier this year. Basically, I had a leak in my system and to replace the R12 would have almost paid for the kit, and then if it ever leaked again I'd be worse off. Once you're looking at having to refill the R12 system, just do the conversion. The savings on the refrigerant alone justifies the change.

94vettin

I had the conversion done on my 87, I had an AC shop do it becasue I did not have the 134 gauges and was concerned about charging it. I had a blown compressor and of course the r12 freon price justifies the conversion. Not sure what year your vette is but when I initially talked to the ac mech, he said that the early c4's didn't really have the greatest fan and that I probably wouldn't be impressed with the cold air. I did a little research on the web and found a performance orifice tube, sorry, I don't remember the name, but if you find it you will know. I replaced compressor,condensor, and orifice tube. I had the system flushed which is important in order to get the all the r12 oil out. One thing to keep in mind is that your car will take less R134 than r12. If my memory serves me right, it took 1.6 lbs of r134 verses 2.2 of r12. Well anyway, the system worked great, ac mech was impressed, I had low 30's blowing out of this thing in the hot Texas summer. If you must do it yourself, go to an AC shop and get the seals and valves, I was advised not to use the Autozone kit. I guess it depends on how long you want to keep it. Good luck. RD

Mr Mojo

Had it done to my truck last year, cost me $350 for a used compressor(needed to be replaced anyway) and whatever else is needed and labor was included in that price.

DarkHalo

Thanks for all the fantastic advice guys. I appreciate it. I think Ill prolly replace the hardware myself then take it to an AC place that does our company cars and always gives us a break on our personal cars and have them flush it good then fill w/R134. I saw a place that sells the performance orifice tubes earlier today too. Mines a '91 and youre right that Im not impressed with the volume of air it puts out. Frankly my '95 S-10 puts it to shame as far as that goes. Maybe this wont be as expensive as I was expecting.

white90conv

I simply evacuated the system, added some new oil and charged with R134a. It has worked fine for 3 years. The cooling is excellent. In theory, there is a problem with the hoses being porous to R134a but an article published by the EPA indicates this is less of a problem than expected since the oil reduces the porosity. My compressor does whine a bit but I doubt that this is due to the conversion. If your system has been opened up for a while, then you may have to replace the accumulator since there may be moisture in the system. I got a new accumulator on the web for less than $35 but I have not needed it.

jtfrog

Did mine for 350.00. Doesnt get as cold at idle on 100 degree days. But weel worth the money. What is this performance orfice tube and what is the advantage?

dtorc4

Since all of my A/C components were working well, I just did a $35 AutoZone conversion. That was 2 years ago and it still blows as cold as the day I converted it. :cheers:

scorp508

I'm liking the sound of that. I might go find someone who can pull it to a vacuum for me.

onedef92

I had mine converted over two summer's ago. There is a kit, but I don't have the name or number handy. It contained a new dryer, high and low pressure fittings and O-rings. I kept the stock expansion valve, compressor and other essential components. Mine blow's ice cold with R134a now!

SunCr

With your access to tools, you can't find a vacuum pump & a manifold gauge set? If you have a compressor (you need about 5hp or better), you can buy a cheapo vacuum pump through Harbor Freight tools for about 9 bucks. Hook up the inlet side to the compressor (make sure there's a decent water filter on the compressor line) and the outlet to the charge hose on the Manifold Gauge Set. Attach both the low side and high side hoses from the Gauge set to their appropriate fittings (most sets will need an adaptor for the GM high side fitting. Turn on the compressor, open both high & low side valves & run it for about an hour. The manifold gauge set will immediately show vacuum for whatever altitude you're at, but let it run. After you shut it off (close the Gauge valves first), vacuum may drop a few inches while whatever moisture is left boils off. Run it again until it holds. Then refill it with about 80% of the R12 charge (if switching to R134) and the right amount of oil (most Vettes are 8 ozs - and this will be somewhat of a guess because if all you replace is the Drier, an ounce or two could still be in the compressor of other parts - err on the side of too much - it ain't gonna hurt it). Before doing all this, replace any of the parts that are broken or leaking. At a minimum, replace the orifice and Drier with at least half the oil charge going into the Drier.