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240 240 a/c - What to do next?

Owsley

Owsley

Active member
Joined
Dec 3, 2008
Location
San Francisco
Sent the '87 240 to the independent Volvo mechanic. He charged it (again) with R134a. Barely gets cool. He put an R134a splice with fitting in the low pressure hose, but did nothing on the high pressure side and says it's hard to get to. He will only charge by low pressure readings. Without checking high side pressure, how do I know if the problem is the compressor or something else? He talks about the sight glass, but from what I understand, with R134a, reading the sight glass is ineffective. The guy who did an older Japanese car of mine said he charged by weight only. I know I'm not going to get 30 degrees, but I should be getting better than I am. What's the next step? I'm looking for advice, whether by tweaking R134a or going hydrocarbon. I'd really be ok with doing hydrocarbon, but every time I check a thread on it, it either dies or is pretty inconclusive. You can prvt me if you don't want to post to the thread. If I'm going to blow something up, I'd rather it not be MY car.
 
Have you checked the valve to cut off the heater core? If it doesn't close all the way then basically you're running your heater and your A/C at the same time. Mine was faulty a few years ago and I could never get the air cold enough even though I new everything else in the system was correct.
 
Unfortunately, 134 in a 12 system isn't gonna be great.. the 12 stuff is just too small. I've read about some variable type of orifice tube/expansion valve that I think fcp sells that helps specifically in cars that have been retrofitted to 134. What kind of orifice tube are you running?
 
My brothers car is a 91 bmw and it was converted to 134a. It blows kiind of cool and the hvac expert where he works says all is fine. That car having r12 originally let bmw use this tiny little compressor. The R12 was a much more efficient heat transfer chemical than 134a. So to compensate they used larger evaporator and better condenser units in the 91-93 240s for example. The 91-92 cars still used the R12 but 93 240s use the 134a. 1991 was volvo prepping the car for it. The system was also changed from an expansion valve based system to a orifice tube system.

So what that means is it would be helpful to make the evaporator and condenser more efficient in your car. Or go to a more efficient refrigerant. Another thing volvo did was add a pusher fan on the front of the condenser. This helped both my r12 turbo and the 93 wagon came with a pusher fan. But those mid 80s 240s having r12 don't usually have the pusher fan.
 
What he said..........................

16 Spal lear jet engine but a 12 or 14 inch will do the job. If I had it to do it over again, I would still buy a "too big for the application" 16" cuz I like the roar.
 
Pusher fan sounds reasonable. I won't be installing myself, but can someone recommend a SPAL fan that will easily fit? I don't want to grossly oversize it because I'm still running the stock alternator.
 
holdenjp said:
Have you checked the valve to cut off the heater core? If it doesn't close all the way then basically you're running your heater and your A/C at the same time. Mine was faulty a few years ago and I could never get the air cold enough even though I new everything else in the system was correct.
Click to expand...

Want to go into details about this. I checked this a day go and when the heater valve is set to cold it closes all the way and when warm it opens all the way but Im still getting hot air out of all vents at a rather slow rate, no blower motor on.
 
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