I have a 1990 toyota liteace and i'm in the process of retrofitting the a/c from r12 to r134a, the whole system were already flushed and the receiver/drier was already replaced, how much oil will i put to the system? the total amount if possible? Is there anybody who can provide me info, thanks.
p.s.
this is a dual a/c with coolbox
- (#8225) gilbert, 27 Apr 03 4:53
Do you mean gas? Figures on AceAnswers IIRC but I think it's 1350 to 1450g. Best to check.
- (#8286) Ian Dunse, 28 Apr 03 8:36
no, he means oil OK, best bet is to ask your local aircon specialist. Ian, this might be in the US book, if you get a chance to check...
- (#8287) david miller, 28 Apr 03 12:33
yes i'm asking about the quantity of oil not the refrigerant(r134a),thanks
- (#8288) gilbert, 1 May 03 8:59
If you have removed all the oil from the system, then you will need to work out what amount of oil it will need, add up the total pipework length+ 2x condensers+ 2x evaporators + compressor. Incidenatlly, which type of oil do you intend to use? as the original pump would have been designed to run on a mineral oil with the R12 refrigerant. As you will obviously be converting over to R134a you with need an ester based lubricant. To help you, when I retrofitted our Townie over to R134a, I put 200ml of PAO68 oil back in, this is a universal oil, that floats over any of the old mineral oil left in the system. However we don't have a cool box, so you may want to add 40ml or so extra if you have one. Don't forget, the molecules of R134a are larger than R12, so you need around 15-20% less weight of gas on R134a, and it will never get quite as cold as it did under R12, as the refrigerant is less efficient. Ah well! the price for being 'environmentally friendly'
Hope this helps, regards Rob.
- (#8289) Rob Drinkwater, 1 May 03 13:17
The US van manual which carries details of the same aircon system that is in our Townies states 20ml of compressor oil if the Receiver has been stripped down and 40-50ml if the condenser has been removed, which I read as being the total for the system.
- (#8290) Ian Dunse, 2 May 03 0:52
thanks guys, i'm working on it
- (#8344) gilbert, 3 May 03 10:08
Ian, allow:-
20-30ml for receiver drier
40-50ml for main condenser
10ml for secondary condenser
40-50ml for main evaporator
20-30ml for rear evaporator
50-100ml for compressor
some? for pipework length.
I would estimate whole system would require about 250ml ish for the whole system if it is totally dry.
I would think that the PAO68 might be best as is contains a seal swell agent, that may help those tired seals. Incidentally Gilbert, how old is the van, if it's late it should have neoprene seals on the a/c system, this is better that the older rubber seals that can be affected by the R134a.
HTH Rob.
- (#8345) Rob Drinkwater, 5 May 03 13:37
Thanks Rob. Never having (yet) the need to play with my aircon, I could only quote from the manual. Which doesn't seem to be as comprehensive as your hand-on observations. Thanks for the info.
Ian
- (#8346) Ian Dunse, 6 May 03 6:10