Compressor and R134a

Gawernator · Gawernator's Garage

So, I'm installing my replacement A/C compressor tomorrow. I imagine the O-rings inside are going to be pretty old/dried out and to use R134a you need a new set of O-Rings, right? I read a thread on rennlist and got conflicting reports. Some people changed the fittings, hoses, o-rings, drier and flushed and everything. One guy changed just the fittings, removed the R-12 and added R-134a and says it worked for 5 years. I already have the fittings and everything, would I be able to take the o-rings out of my old compressor and re-use them in the replacement?

John_AZ · 07-12-2012, 04:05 PM

Never--they are deformed when installed.

John

chamilun · 07-12-2012, 04:18 PM

just change the o-rings (autozone has a package of green o rings, but they are on one of the shelves in the back) of any hose you disconnect. Change the drier, change whatever o-ring you mess with, vacuum for 30+ minutes, and charge her up.

Gawernator · Gawernator's Garage

Roger that

zedsn · 07-12-2012, 05:55 PM

My R12 system in my older nissan takes r12 as well but I have been looking into an alternative product called duracool. It is enviormently friendly but is as cold as r12 and seems to be more compatible with the r12 comressors. May be an option for you to look into.

Gawernator · Gawernator's Garage

I was considering those alternatives with my last 944. But I bought this 944 and it was already completely retrofitted for R134, with the fittings and seals/drier etc. Only reason I'm dealing with this is because of a pretty catastrophic compressor failure.

zedsn · 07-12-2012, 06:12 PM

You said catastrophic failure. Could you have metal particles still in the system? If so you might want to seek professional help.

Gawernator · Gawernator's Garage

No, what happened was that the tensioning strut/adjustment rod snapped, the ear/bracket on top of the compressor sheared off, taking both the alternator belt and PS belt with it. I ordered a replacement compressor, the missing mounting bolt, a PS belt and alternator belt and a tensioning strut. Today I also picked up R134a with oil, just not sure how the seals will be in this used compressor.

zedsn · 07-12-2012, 06:19 PM

Could be hit or miss with a used comressor. Don't over charge the system.

Gawernator · Gawernator's Garage

From what I can tell, 30 OZ of R134a and about 4.4 fl oz oil. According to this bulletin: http://www.944time.com/porsche/2005images/944_ac.pdf

mikepellegrini · mikepellegrini's Garage

Quote:

Originally Posted by zedsn

My R12 system in my older nissan takes r12 as well but I have been looking into an alternative product called duracool. It is enviormently friendly but is as cold as r12 and seems to be more compatible with the r12 comressors. May be an option for you to look into.

+1 on Duracool. I've got it in several vehicles and it works well.

zedsn · 07-12-2012, 06:37 PM

I saw a TV ad recently that had a large can of 134A that actually had a gauge on it to tell you when your system was full. Maybe autoparts stores carry this and might be worth while looking in to.

Gawernator · Gawernator's Garage

I can't remember the brand names, but I got a big can of "fancy" R134a from an O'reilly's here in CA. Blue can, with a hose and a gauge attached, also has 4 oz of oil mixed in. Bought another can of R134a that had a bit more oil to add on.

chamilun · 07-12-2012, 08:51 PM

the oil is either already in or needs to be added to a replacement compressor. if used, Id drain it all out and add back according to label.

cheap set of gauges is a good idea as well, as troubleshooting without low and high actual pressures can be a bit tricky.

If anyone wants to know how a $150 new compressor can be fit to a 944, PM me. Requires finding the right brackets and using a few washer spacers, but the pulley lines up perfectly, and best I can tell, is what these sanden or similar kits they sell are using. I installed the 'kit' on my 83 SC a couple years ago, and the compressor I just installed on the 951 is very, very, very similar

Gawernator · Gawernator's Garage

You never re-use A/C oil, right?

1982_928 · 1982_928's Garage

Replace the o rings on whatever hoses you disconnect, and be done with it. R12 compressors work fine with 134.

You know there is still oil left in it, so just add a little and be done.

Also, people, just buy some proper gauges and hoses.. Those "Fancy cans" are terrible.

JAXTURBO · JAXTURBO's Garage

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John_AZ · 07-13-2012, 05:46 AM

++1^^
Member Kuehl aka Griffiths

Griffiths.com

John_AZ · 07-13-2012, 05:54 AM

Quote:

Originally Posted by zedsn

I saw a TV ad recently that had a large can of 134A that actually had a gauge on it to tell you when your system was full. Maybe autoparts stores carry this and might be worth while looking in to.

WalMart had it in the latest ad-AC PRO:
Walmart.com: AC Pro Professional Formula Refrigerant: Automotive

Why spend $40 a can when you can get a R134a for $10 or less a can??

A gimmick.

Get a set of Automobile AC Freon hoses at Harbor Freight for $40 or less with your 20% off coupon in Sundays papers and a can of R134a for the same price.

John

snake1996 · snake1996's Garage

Because the compressor broke off the mounting, all you really need to do is replace the compressor and o-rings, evac and re-charge it. If the dryer is original now is a good time to replace it. If it has been replaced already it will be fine as is.