Hey gang, so this post is for gathering information from those of you who already have the experience and knowledge I’m trying to gain.

Here’s the deal: I recently bought an 86 convertible, of course with the L98, and an auto. Also, manual AC as all 86 ragtops were. It’s got the original R12 system in it but it’s empty and no longer charged. I’m looking into converting it to 134a and am finding all sorts of varying info on what’s needed and how to go about it.

One vendor sells a “retrofit kit” for 36.95 that includes a whole bunch of new o-rings, connection pieces, and ester oil and says that’s all I need. (I’m quite skeptical of that claim)

Another kit sells for 64.99 and includes new schrader valves, flush solvent, and ester oil, but also recommends replacing o-rings, drier/accumulator and/or orifice tube, which of course are NOT included in the kit. (Which makes no sense to me - why make a “kit” but not include everything you need??)

A third kit sells for 337.99 - 359.99 depending on the vendor and includes a new compressor, receiver drier, evaporator orifice, oil, seals, fittings, and adapters.

So clearly three very different “solutions” for the same end result. What experience have any of you had in converting an early C4, and which of the above “solutions” have worked - or not worked? Any input/advice/experienced information would be appreciated.

Thanks all, and stay healthy!

 

I should think that you need a new accumulator as oil is stored therein.
Of course you will need the new schraders too.

You might begin with a pump-down and leak test to find how badly it leaks.

 

If you don't have a gauge set and a vacuum pump have a pro do it. If it's empty were did r12 go? What's going to take to fix that first.
Retrofit : An 86 you want to replace accumulator, because it's ancient. Kit wise fittings, 8 oz charge of pag oil, 3 cans of 134a, and a label that says it was converted, Oil type and charge amount.

 

PAG oil doesn't mix with the mineral oil that is already in the system. Use 5 ounces of ester oil and 2 1/2 can's of r134a. Get any old oil out of the compressor if you can. I always flush and change the O rings and accumulator. Also the cycle switch to one that's set for r134's lower pressures. If it holds a vacuum after a couple hours you should be good to charge. My '87 and '90 both blow better than 40 degrees below ambient after conversion.

 

Will the R12 hoses work for the R134A? I thought I remembered that the R134A hoses had an extra barrier to prevent leaks or something?

 

What do you flush the compressor with to rid it the old oil?

 

I did the conversion on the 85 and now working on the Olds 88. The old hoses will work until they go bad from age.
I did the Ecklers conversion kit with compressor but I also took the components apart and cleaned them with some cleaner from autozone.
I used 8 oz of ester oil , most in the compressor and turned it a few times. It took 40 oz of r134 but if it is cold you can just stop adding.
It has been working for 4yrs now, I also replaced all the orings before I pulled the vacuume; You need the orifice tube because of the clogging.
The dryer is really cheap and should be put on last. Good Luck!

 

correct - new delco replacement hoses are designed for use with 134a, HOWEVER on my conversion, I used the OE R12 hoses - 5 years since my retrofit, and still holding the charge - don't seem to have hose issues, so i'm wondering if the hose thing is more hype than actual fact - don't know and can't say for sure. I figure you can buy a lot of 134a Freon for what a new set of hoses cost.
(OP) key points with the conversion, flush the system, new O-rings, pressure fittings, orifice tube, LP cycling switch, and accumulator/dryer, ester oil, and re-charge. personally and my 2-cents - I would avoid the $39 conversion in a can thing, but folks can do whatever they want. I may have gone overboard on the conversion costs, but FWIW, I have no regrets.

 

several, readily available flush kits out there - google "r12/r134a air conditioning flush kit"

 

I have done this conversion many times. Absolutely the first thing that should be done. Most skip this step.

The AC condenser for R12 is a little different than 134. I took the advice of an expert on my 81 corvette an went with a condenser designed for 134.

car blew about 37 to 40 degrees out the vents in mid summer. All the o rings should be replaced on the line connections. 134 operates at a higher pressure. They will eventually leak if not replaced.

 

This is all great information and VERY helpful! Thank you to all who contributed! And thanks in advance to anyone else who has more to offer! Much appreciated! I’m hoping to get this conversion done the correct way in the near future, and then not have to use my perfectly working, newly cold R134A AC system since I’ll be driving with the top down. Ha! But I still want to know it’ll work if I need it. Thanks again to all!

 

I drive with the top down and the A/C on all the time!

 

Pull your ac compressor and drain it.
when i did mine, everything came out.
first time around i bought some flushing pressurized cans from napa.
worked well.

Later i got a flushing tool that uses compressed air to push the flushing solution through.
Refill your self, much cheaper to push a ton of cleaner through.
Cheap on amazon if you have air.

My system had spent some time open as well, ran the pump by hand to flow the cleaner through it, and flushed the condenser and evaporator both directions until i was satisfied.
ran it for a good year or so until the original compressor started acting up.
had found a slow leak in one of the rubber lines, so new compressor and hoses with another solid flush.

Not much to it, plan on replacing that drier every time the system is opened.

if diy, then buy a vacuum pump.
The money saved more than covers the cost.

My first go around i got a kit from napa, i forget what it was, but it was said to not react with the mineral oil and compatible with the r34... maybe it was mineral oil.

With the new pump, hoses, better tools, and knowledge i now run pag 150 oil.
the early compressor type my car has is noisy (84), thicker oil quieted it down a bunch...

Also, watch out for black tar looking stuff.
i had black rock looking things come out of my original compressor the first flush...
If you see it, pay special attention and think about replacing things.
Very hard to get out, causes havoc.

Cell phone, and too lazy to make more sense out of this/formatting.
hope it makes sense.

 

I recommend resealing your compressor. The front seal wears and deteriorates from age. It is a common place for a leak and it is much cheaper to install new seals than to replace the compressor.

 

But if you don't get it right, it is going to cost you another evacuation and fill

 

Once again, thanks to the additional posters for the info!! This is all VERY helpful! Good to know there are so many helpful and knowledgeable people out there in our little corvette world!

 

AutoZone has a kit with a lifetime warranty.

 

just some general FYI - since the OP is talking 1986, NEW service replacement AC Delco R4 compressors can be purchased for around $175. IMO, with parts and tooling, not sure it's worth the costs and effort to rebuild one of these things. I went plug and play new on my conversion because I had a compressor bearing going out and my original would have needed a complete overhaul. 5 years now on the new delco, and not a hiccup -

 

I think that unless you have some need for it to be original, rebuilding is getting, more and more, to be a thing of the past.

 

As long as they have a kit that supplies everything needed… That would be great