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Retrofitting of A/C

ab1

New member
Joined
Feb 27, 2015
Location
Melbourne, Australia
Retrofitting of A/C to a 164

Hi as I'm sure you guys are well aware this topic has been well covered with respect to 240s (Dave Bartons write up was excellent as well as a few others on TB) however I feel im in deep water when it has come to fitting entirely new parts to a 164. I have a couple questions that hopefully someone may be able to assist with.


- what size fitting do the late 240 evaporators take (ie the aluminium one for r134a) I know the the big line is a 32mm nut but not sure what this is in ac terms and also the smaller line coming out.

- also using a sanden style sd508 (supposed to be for a Jeep Wrangler) which I believe is the same as a 240 compressor. does anyone know the fitting sizes for these.

-where would I mount an orifice tube(is there a way to know which type is suited to my setup) and where to mount a high pressure cut out (the low is already in the 240 gm style drier receiver)

- I assume that wiring the cut off switches just involves wiring them to the compressor so that they will cycle it on or off due to varying pressure

- will an A/C shop be able to work out the required amount either freon or HC required given the system doesnt have a known capacity since the parts are essentially universal...

as its starting to get hot down under im very eager to get this all together. this is essentially the last step.

I hope to recharge with a hc refrigerant as from what ive read it is much more efficient and despite going for a parallel flow condenser I could only fit a 21x12 inch one due to restricted space on the 164 facia.

to answer a question from my last post I have taken the advice that I was given and gone to a hydraulic shop rather than an a/c shop and they were much more willing to help so looks like it may be a good option. I can get a quote once I find out the fittings I need.

Cheers!

(I hope this is posted in the correct section)
 
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Thought someone would have offered advice by now. Ok. I'll chime in. The evaporator, compressor and condenser are all standard sizes and the same sizes used in my AC conversion page.

I can't offer an answer about an orifice tube. No experience building that type of AC. Mine uses a TXV.
Dave B
 
I think ive sorted my fitting sizes with my new drier as it had hex plugs on it which identify the size of the low pressure side

yes the orifice tube has me a little confused I would imagine it would would move around a rubber line. im not sure whether its seal holds it in place
 
Eveything is sorted and functioning.

overview of the system is a gm accumulator, 240 evap (1990s+), 21*12 Parallel flow condenser. Charged with Australian equivalent of Duracool with a charge of 240 grams or 8.5 ounces.

Blows nice and cool on the freeway however idle performance and around town could be better in 86 degree heat. im not running a pusher fan which may explain this as the 14" i originally had on the rear of the radiator wouldn't clear the front so its just the old viscous which i hate but it does the job to keep it cool. it could also be the choice of orifice tube i think its a white one with a single black oring that its in there at the moment. i wanted a variable style but couldnt find one in australia.

touch wood i dont have a leak but if thats the case ill possibly swap it over then. when the bloke went to charge it up the cycle switch was faulty so he had to bridge it in order to charge it up. the new switch is now in and the compressor never really seems to turn off whether thats just the way its meant to be im not sure.

Overall the horrendous task has been worth it. but ill see how it goes in 105 degree heat that will be the test.

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The last red block AC systems were all CCOT (clutch cycling orifice tube). They need to cycle, rather than be straight wired on. I believe that late 7 and 9s use the dash controller with the 3 knobs (forget the acronym) but there is also input from the ECU. Can you find the control hardware from the 91-93 2 series which is CCOT and apply to your vehicle?
 
yes mine isnt straight wired in its wired through a high pressure trinary switch as well as the low pressure cycling switch on the accumulator identical to the late 240. my understanding was that when the pressure drops below like 15-20 psi is would cut off and therefore cycle.

i wasnt aware of anything else on the late model 240s that controls cycling other than the switch on the accumulator
 
Check the Maint sub forum; a year or more ago there was an excellent thread built around the 91-93 AC systems used in the 2 series family. I believe the control schematic for the 93 was posted.
 
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