134-a conversion questions
 

Any of the A/C gurus have any experience or a point of view on whether the two sources below (an o-ring kit and alternate -- non Pelican -- supplier of a R134a conversion kit) are worth considering for a knowledgable shadetree mechanic?

O-ring resto kit: http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7983820256&catego ry=33544

R134a conversion kit (w/ Kuhne compressor): www.griffiths.com

You can do the swap over to parts in your own garage. But you still want a professional to evacuate the system, and possibly charge it. If you've got an open system, and you add freon without evacuating, you won't get a full charge or full amount of freon in there.

Bought a good condition preowned 134a compressor and condenser from a 968 owner... very cost effective and positive solution. :D

You shoudl still get the system evacuated by a shop - you need to have vacuum pulled on the system to get the correct charge. Otherwise, you are comprtessing freon and air - temps will run 10 degrees or more higher.

AFJuvat

The AZ Republic newspaper had an article that R134a is being replaced by R135 in Europe and that R134a is going to cost more and be less available. If this happens, will the systems be compatable? A service tech told me that R-12 is available and the prices have come down (somewhat) due to recycling.

John_AZ

1988-924S
1987-924S

how much will it cost to have a shop do the whole job replace the r12 with a working r134

Dont know the total $$ to complete the r12 to r134a conversion yet, still accumulating the parts, but I anticipate spending roughly $600 on the parts -- including compressor and condenser (family price), new C-to-C hose and C-to-Evap/Drier hose, new Evap/Drier and O-ring kit. Plus, I will have to get the r12 system evacuated (minimal $). Debating whether I take the car to a shop for the wrench work, but will post a reply if I get lazy and need help. :o

r134a was only developed as a more enviormentaly frendly gas until
a better alternitive was made. It is better for the world than r12 but
still not harm free.
20 years ago I had R11, R12, R22, R500, R502 & R717 as the main gases in my trade, now there are around 30 different types, and about
another 20 brand names that never took off.

Providing a r134a conversion is done by the book , and the equipment is in reasonable condition it works fine, but it is not a DIY job for long
term use.
Russell

after doing my R134 conversion my compressor cooked. I have a feeling the R-12 wasnt all out. never got around to changing it yet.

Most likely incompatible oils that caused your compressor failure, or not enough oil, or perhaps it just ran too long low on oil.

I've converted several systems over to R134A. Ideally you would change all of the O-rings, the compressor, and go to a higher effeciency condensor (i.e. a serpentine condensor), but this is not practical for most of us. The usual route is to change all accessible O-rings, the receiver/dryer, drain all of the old oil you can, drain the compressor, condensor hoses, etc. Then reassemble with new O-rings, vacuum the system and refill with R134A.

The problem with R134A, is that you will see better cooling at highway speeds, but decreased cooling with lower compressor speeds. This is normal. Compressors designed for R134A are slightly different inside, they are designed such that they will build a higher head pressure at lower compressor speeds. You will feel a difference going with a serpentine condensor, and a R134A compressor, but I can't quantify the difference for you. Changing one or the other may or may not yield results. For the most part, people are happy enough with it if they do what I described above. If they're not, I change the compressor first, and the condensor if they are willing. This usually results in very happy people :)

I am definitely going the "ideal route", but reading between the lines above -- I take it that you are saying that in any case a proper conversion/refresh also requires a new receiver/dryer, C-to-C hose and C-to R/D hose in addition to the new o-rings?