PrerYDoG

Okay - I have R-134A refridgerant in my car. I know this because when I did the IceShark headlight update, I was under the car staring at my compressor and said "WOW, it has a Sanden label on it that says R-134A." Yeah...it was like serendipity. Anyway... It's summer now, my heat clip is fixed, and I'm going to the beach this weekend (leaving on Thursday). My cooling seems to be...well...sub-par, even on the level that I'd expect from a Porsche (which doesn't have descent AC to begin with) that has been converted to R-134 (which isn't as good).

My question after all that rambling is...how do I fill this thing up..what pressure does it run at? My dad has the gauges and hoses required to hook to the can and the high and low pressure lines to do a re-fill (we filled up my last Porsche with R-12...shhhh, don't ask how we got R-12!). He's never done an R-134 refill, and neither have I. What's the trick, or the difference to doing this?

Thanks

Porsche-O-Phile

There are two inlets / valves on the back of the Sandens (I know, I'm in the process of doing this conversion on mine), one on the "supply" and one on the "discharge" side. I think you connect to the "supply" side. Make sure you add some oil too. I've heard that over long periods of time if there's any leakage from a system the proportion of oil to refrigerant will drop as people add cans of refrigerant but add no oil. This (lack of oil) is what kills compressors. Just do a search around here for a/c-related stuff, there's a LOT of good information on this subject.

Good luck, let us all know how it turns out.

Luis de Prat

The R134a recharge kits available at your local auto parts store like the one from Interdynamics ($35) come with fittings, a charge hose and 3 cans of refrigerant that includes a lubricating ingredient. Easy DIY provided you can raise the front end of the car on jackstands.

Worked for me!

PrerYDoG

How much pressure can I put into the system? I'd hate to overpressurize it with refridgerant...

Luis de Prat

I looked up the A/C filling capacity in the owner's manual and followed the instructions in the kit. According to the instructions on the can, the refrigerant is formulated in such a way that it's not likely that you'll overfill.

Porsche-O-Phile

Double check the fill location too, I don't want to misinform you. I just recall that someone tried attaching the can to the discharge side of a compressor and almost blew up the can! Be careful and please double-check me, because I'm not an expert on this, but I'm 90% sure you hook up to the INLET side of the compressor.

PrerYDoG

I wasn't really aware of 2 seperate locations that you could hook onto on the compressor, I was only aware of the high pressure and low pressure line areas that you could hook onto and charge from. I'll check that out. Thanks Luis - glad to know I can't overfill.

jd944

The service ports are marked "S" for suction, or low side and "D" for discharge or high side. You want to charge to the suction side only. I had to make a special hose that uses to old r12 screw on connector because the r134 adapter fitting wouldn't fit on my compressor. When converting from r12 to r134 the system will only require about 80% of the normal r12 charge. On my 84, I have found that if I charge the system until the high side reaches between 180 and 200 lbs.,(on an 80-85 degree day)it works great. Do not over charge the system as you will most likely do damage to the compressor or blow out a hose.

951Tom

One trick I like is to fill a bucket with 110F water and put the can in the water while charging the system. 120F is the max temp you can subject the can to so use a thermometer, no guessing!! This will safely raise the pressure in the can & push all the freon out & into your a/c system quicker so keep a close watch on your gauges adding a little at a time while watching the vent temps. This is important also...do something to hold the revs around 1500-2000 rpm during charging. I use a feeler gauge in the throttle stop. A/C work is fun to do and the DIY $$$ savings are enormous.