I installed the Enviro-Safe (ES 134a) 4 years ago and have excellent results , like Sanchez was getting low 30s at the vent when measured.
Evacuating and pulling a vacuum are sometimes confused.... if you have R12 or R134 you want to go to a A/C shop and have it removed (evacuated) after they have used sniffers looking for leaks. If you reinstall OEM R12 or R134 you need to pull a vacuum to get the moisture out of the system, it will also remove "some oil", so your stuck with complete oil service.
If you have done the leak checks and removed the old refrigerant, you are done with the A/C shop... The rest you can do yourself at home in the driveway. The prep and installation of ES-R134a (This is replaces either OEM R12 or R134a) does not require pulling a vacuum, as ES is moderately moisture absorbent and prevents corroding the internals of the system.
Fills from low-side service port with a one-gauge-hose adapter. First well shaken can goes in upside down with out compressor running. You can calculate number of cans or service to correct low side pressure with second and maybe part of third can with compressor running.
A couple of recommendations. (No flush recommended)
1 Get a set of green o-rings with the proper lubricant for them, use as needed (any auto supply)
2 (Optional) replace the receiver/dryer. Cheap and easily accessible above fan shroud. ( instructions include how much oil to added to dryer before you install it...2 oz. from memory)
3 (Optional) change the evaporator valve behind the engine if you do not know it's history (OEM part is fine)
4 Enviro-Safe has oil and leak detection/sealer cans with coolant charge if needed ... if you have the compressor out for any reason, follow instruction for changing all the system oil.
5 I converted from a OEM low pressure cut-out-thermo-switch to the modern Low & High pressure cut-out switch (R134a-HLPS). I put it on high pressure R12 port and left the old low pressure switch in back of compressor unconnected electrically. The HLPS switch provides a ground for the compressor clutch { low pressure no gnd, high pressure no gnd, correct operating pressure > clutch has gnd } (new or rebuilt compressors can be ordered with either switch installed). Does away with all of the thermo-fuse electrical mess ( I made my own electrical harness)

For those in really hot environment, you can replace the condenser with modern aftermarket high capacity unit that is direct fit.

Tech website "When R-134a replaced R-12, PAG became the factory specified oil. You'll find three common viscosity's when choosing PAG oil. PAG (ISO) 46 - Thin PAG (ISO) 100 - Medium , PAG (ISO) 150 - Thick (GM recommends 135). PAG oil is very hygroscopic (absorbs moisture from the air) and should be exposed to the atmosphere as little as possible while charging an R134a system. Can you mix Polyol Ester (POE) and Mineral Oil (MO) together?

For a new evaporator valve, the tape with tar backing can be found at usual hot-rod web-sites, but I rapped mine with final layer of aluminium heat insulating tape (second time) as there is so much heat from back of engine, you will find all the tar on top of you transmission after a few weeks (yes a big mess). Rap your heater hoses close to expansion valve with aluminum insulation tape also

With ES can do all the system maintenance with out going to an A/C shop and it will out perform the original R12 for cooling. Yes it is probably 99% propane and the 1% mystery ingredient that makes it a proprietary blend !!!!!! EPA has no problem with this product. You should use caution as when working with any flammable product.

Please take the time to update the placard on your hood as to what refrigerant you have installed,
I would add the type of oil that you are using (no mysteries for the next guy)

Rgds
David

 

Great information David, thanks for passing it along.
Dave

 

David,
Once more great information. I am about to replace Comp. Drier, Exp. valve and would like to also do the Condenser. You stated "For those in really hot environment, you can replace the condenser with modern aftermarket high capacity unit that is direct fit."
I need a direct fit unit, as I don't have an AC shop round here that does any custom hose/connection work.
Do you have a part number/source that I can follow up with?
Regards, Ian

 

Ian

This is one unit, I could not find my notes on the others that I looked at

RetroAir sales@classicautoair.com - 877-342-5526

Jaguar XJ6 lll " High-tech Multi-Flow Condenser"

I did not check this out in detail https://www.classicautoair.com/paral...-conditioning/

see their catalog: page 57 for condensers and page 61 for R134a Tee fittings

Rgds

David

 

I had a similar problem on my 84 Van Den Plas. Went thru all the same issues everyone else did. Got to talking with a old time A/C guy who said the calibration of a expansion valve is different from R12 to R134A. He showed me what he did for the adjustment. On the expansion valve for a series 3 on the firewall side of the valve inside there is a hollow nut with a Allan end. Turn this nut inward three full turns against the spring inside. I performed this modification on my vehicle and it actually will hit 28 degrees Fahrenheit at center vent. Next time your in there try it. What's a few scarred knuckles versus the outcome.



Larry Louton

 

I will definitely try that and post the outcome. I’m a rookie mechanic who fears breaking stuff and generating more expenses, which is why I left it alone. Lol

i’m just thankful autumn is here now.

 

If you are going to remove the TX valve, use a back up wrench on the TX valve and loosen the nut on the line going into the evaporator. Failure to do this will cost you dearly. If that line breaks, the only repair will be to remove the Delanair unit completely to access the evaporator.
Spray liberally with WD40.
You will need a 5/8 wrench on the TX valve side and a 7/8 on the evaporator side line. You have to turn the nut on the evaporator side line (7/8) to remove the TX valve.
Proceed with caution.

 

And the system should be emptied.

 

Just a note on the Enviro-Safe stuff...

I talked to my shop about it today and lo and behold, the shop owner has experience with it. Actually went through a training class on how to use it with R134a and R12 systems. Some of his takes on it ...

1. He had no safety concerns with it. He told me one of the new R formulations (don't know if he meant for vehicles or for home HVAC) was basically propane/butane and that's the direction the industry is moving.
2. If you get a leak with it, unless it's a catastrophic evacuation (such as, accident damage, hose completely ruptures, etc.), the non-flammable portion of the mixture is a smaller molecule than the coolant and will leak (and de-pressurize) first, thereby removing the tendency to propel anything flammable out of the system.
3. Be aware of compressor warranties, however. This stuff will likely void a compressor warranty if the company does a tear-down upon return. The guy who trained him had it happen to him.

Having said all that, I'm probably going to test this out on my '87. I can't get my R134a system to get down under 50-ish degrees F and thus, it will not cool when the days are at their hottest.

Jess