Charging 911SC A/C system with Freeze 12 - a/c gurus....

[TonyG]

A couple of questions....

'82 SC. Stock A/C setup. Purchased car. Rebuilt engine just to do it, so the car is perfect. Everything back in and it's time to get the a/c up and running...

The car, when I purchased it, had all the a/c components as stock, and the clutch on the a/c engages. But I don't think there's any R-12 in it. I heard that there's a low pressure switch in the smugglers box, and if so, then I'm kinda stumped as the clutch engages properly.

I engaged, ran the car for a couple of minutes, but the window on the dryer has the little ball.. and the window is clear and looks empty.

So I shut off the a/c.

Today I purcahsed a full set of gauges for R-12 with all the hoses and have configured my garage compressor to pull a vacuum on the system. Years ago I used to do this (evacuate and recharge) to my other cars. I've never done it to a 911.

Here's the questions...

How much of the R-12 substitute stuff (called something like freeze 12) should I pump back into a fully evacuated system.

What should my high and low pressures be when done?

How much, and what type, of oil should I add to the system?


Thanks in advance...

TonyG

[craig001]

I don't know the answers about the Freeze-12, but how did you get your compressor to pull a vacuum? I have the gauge manifold and R-12 for recharging and wouldn't mind pulling my system down for an hour before recharging.

[RickM]

Using one of these: http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=3952

However, they can take quite a while to pull to the right level and many say their lcapabilties are inadequate.

Tony, you may be best off calling the company for those specs. I know Duracool is not a 1 to 1 replacement...be carefull.

[TonyG]

craig001

To get the compressor to pull a vacuum, you simply rig your line to the intake side of the compressor. Then undo the output side of the compressor (since you don't want to pump what ever is in your a/c system into your compressor tank).



RickM

Wow... $15.00

At that price it's not even worth scewing with my own compressor!

I knew these vacuum pumps existed, I just thought that they would cost a lot more that $15 bucks.....

... and I thought I was being slick.... :-)

TonyG

[scottb]

Do a search here on the board. I think the issue of quantity of Freeze-12 has been discussed before. My recollection is that it's a lot less than R12. Otherwise, as Rick said, call or e-mail the company. I'm sure they know the replacement ratios.

Let us know what you come up with!

[TonyG]

Actually... I was looking to use Envrio-Save... which seems to be better than freeze-12

[Jim Sims]

See:
A/C - Need COLD system for ~$1000. Possible?

Enviro-Safe is a hydrocarbon refrigerant and is significantly different than Freeze-12.

Legally (according to the EPA) an R-12 system has to be first truly converted to R-134a (not just the fittings installed but filled with R-134a) before something like Enviro-Safe can be retrofitted.

Note once you install Enviro-Safe you may be on your own as A/C shops may not want to deal with it; their equipment is set up only for R-12 or R-134a.

Jim

[ruf-porsche]

Once you have the gauge set connected to the a/c system you need to open the valves in order to access the system, this is only required if you still have the original york compressor.

[philipguziec]

I hear you can rig an old AC compress from a wrecked fridge as a vacuum pump to evac the system. Anyone done this?

[johnsjmc]

Look at www.aircondition.com for install posted by a guy called "jungle eddy" very good set of instructions for r12 substitutes I think the weight ratio is about 6 oz of freeze 12 equals about 16 oz of r12 but it is easy to overcharge without guages