Pete Pulos

Any info or thoughts on this. Supposedly, no components, o - rings, accumulator needs to be changed. They just use Ester oil rather than PAG oil and they say that it works fine. Chrank and Chrome (Sam Memolo)had this on an episode a few weeks ago. Thougths????

Togo

pete, email me when you find out. i don't know if mind has been upgraded but if not, i think this info would be invaluable.
i hear for the conversion that you may need to change the drier??? i don't remember where i heard that, but check it out and let me know
thanks!

Flame Red

Pete,

For R-12, I plan on using:

http://www.cooltop.net/autofrost.html

I had great success with their other product, Cooltop, which is for 134. Stupid Chysler could not get my truck's AC to blow cold after about four tries Cooltop fixed it right up

Flame Red

[This message has been edited by Flame Red (edited 08-01-2001).]

Nathan Plemons

Pete, isn't interdynamics the brand you can pick up at the parts stores? That being the case, that's what I used and it worked just fine. I can't say how long it will continue to work, but for now it works great.

Ken Hakken

I've taken care of all my air conditioning since 1979. The problem is moisture. If you don't get every micro gram of moisture out of your ac it will pull the flourines and chlorines out of the freon and create acids in the system. These will eat through your harrison evaporator plates and eventually through your condensor tubes. The result will be an expensive repair down the line.

My suggestion is to buy a rebuilt compressor, a new dryer and evaporator oriface. Use a shop vac, duct tape and an old ear syringe to clean out the evaporator, condensor and hoses. Discount Auto sells solvent for cleaning the system. Syringe it in one end as you vacume out from the other ends of the parts. This will clean all oil residue out of the tubing, condenser and evaporator. Replace the compressor (make sure you gap the clutch) and receiver dryer. Use all new o rings. The new dryer and rebuilt compressor come with theirs, but you will nee to buy new ones for the other connections.
I used PAG oil because it is what GM recommends. Measure it with a graduated beaker and use the syringe to put the correct amounts into the compressor, evaporator, condensor and receiver dryer prior to reassembly of the hoses.
If you get a four seasons rebuilt compressor it comes with paper work that explains the quantities of oil needed for each part.

Next you need to pull at least 26 inches of vacume for at least four hours. Vacume is an insulator. As you evacuate the system the moisture in the system will turn to ice crystals. These ice crystals will not melt until they come in contact with the inside surface of the system. When the do the energy propels them back into suspension until they can come in contact with the surface again. This process is a logarithmic decay curve so you never get all the moisture out. Thats why you need the new dryer. It has capacity to finish the job.

Also, make sure the relief valve on the back of the compressor is tight and don't forget to turn the compressor over by hand at least 30 complete revolutions. This clears the valves of oil and lubricates the seal.

If this sounds like a lot you might just want to take the car to a reputable ac shop to get it converted.

Be carefull if you do it your self. I never look under the hood of any car without safety glasses on now. If a line lets lose it's like an explosion. The only thing I can think of that is worse is a battery blowing up. :chevy

SouthernSon

After you put all things back together, take it to a shop to do the vacuum on the system. A wet vane, professional set up is the only way to go. They can then put the 134a and ester oil in the system for completion.

Ray Zavorka

Please, Please, Please, seek guidance form sources other that the Corvette Forum since
this is a serious and potentially dangerious decisoin. I also post and follow AC related
issues on another forum and I am MVAC 609 certified.

The Forum at http://www.aircondition.com/wwwboard/ is riddled with R134A conversions.
Problems with these conversions constitute about 80% of the activity on the AC forum, so
the concept of buying the Interdynamics kit and expecting it to solve your problems are a
farce. There has also been discussion relative to the possibillity if a class action suite
against ID. Take a few minutes to visit the forum and post your inquiry there as well.

Ray

93 ragtop

Pete,
The purpose of pulling a vac. on a system is to boil off the moisture in the system and to remove air etc. We all know that water boils at 212f. at sea level. Yet add 15lbs of pressure to it and it will not boil till 250f. By pulling a vacuum you reduce the boiling point. With a vacuum on the system, (usually you try to pull to 29in or a little more) this will boil out the moisture and pull the air out of the system before the freon is added to the system. Most shops do not pull by vacuum and use the pressure guages alone to get the (proper readings) . They will use a micron guage to show the actual moisture content.

hi-tek-vette

just a minor point ..... the water doesn't turn into ice crystalls ---- the lowered pressure ( vacuum ) enables the water to boil off at room temperature, it's just very slow evaporating the water this way .....you've got a good handle on this type of work !! ........ i use a micron gauge, evacuate to 400 microns, this is a pretty good "field" vacuum .................. always replace the dryer, anytime you open the system .........

89 Bob L

Many people say that in order for R-134A to be effective, you must vacum the system. A new dryer is also recommended for maximum results.

SouthernSon

Ray, if you consider the interdynamics procedure for conversion a farce, what do you think the A/C shops do differently?
By the way, my 'farce' of a conversion on my SL is cooling better than it ever did.


[Modified by southern_son, 2:23 PM 8/4/2001]