Well, it's july in Mississippi. People at the equator are thankful they are not here, where it's REALLY hot. Anyhoo, I have my beloved 87 245 wagon and the ac and all the components work as they should. At some time, my freon was removed and the car was charged with R134 (the new stuff). Thus, my air doesn't blow cold. The system wasn't retrofitted, as my (very trusted) volvo mechanic said, and some new parts will be needed and recharged with freon (r12 I believe) any advice? also, he suggested an electric pusher fan be added to help my current situation. I added a cheapo, and never felt the difference. It died and needs replacing.

 

I understand your problem to be:
- Original AC system designed for R12
- R12 has been replaced with R134a
- Now system doesn't work

Before filling R134a into a R12 system, all the R12 and the R12 oil needs to be flushed out (flush kit) (The R12 should be collected, and not emitted into the atmosphere - but I guess it's all gone in your system). Then the system should be evacuated (vacuum-pump required) and filled with R134a refrigerant (conversion / fill-up kit).

Interdynamics sell do-it-yourself kits. I have used their kits to convert from R12 to R134a on a GMC full size van - and it worked very well. I bought all the suff off J C Whitney (JC Whitney Auto Parts & Auto Accessories - Car, Truck, Jeep, Motorcycle, VW, RV & ATV - Aftermarket Parts & Accessories). You will need a vacuum pump to evacuate the system. There is a cheap one operating on compressed air....(search for "interdynamics" on their website....)
The only modification I had to make to the system was to install different quick-connector nipples on the system. These nipples were part of the Interdynamics kit.
But, there is a hitch....you probably have a leak in your system - usually in the AC compressor. The R134a (the stuff I bought at least) included a leak-stopping agent, so it might work.
Safety goggles and rubber gloves should be used when performing this work.
There is an instruction video available to down-load.

Rgds,
Christian

 

sounds like a plan. I don't believe I have a leak, so hopefully it'll go smoothly and cool-ly. Happy 4th!

 

I live in Texas, so I know what you're going through. Trust me when I say that if you want maximum cooling you absolutely do not want to convert to 134A. Consider the following:

R134A is considerably less efficient than R-12. It was chosen as a replacement because it has "close to" the same temperature/pressure characteristics as R-12. The reality is that changing to R134A in your system will result in a 15-20% reduction in cooling. The new cars cool well because they have larger condensers and evaporators to compensate for this difference.

R134A functions at different pressures than R-12. High side is higher, low side is lower.

R134A molecules are much smaller than those of R-12; they will actually seep through the hoses if you do not replace them with the new barrier type hoses designed for 134A, which have an inner lining to prevent this. Replacing your hoses with the new ones is a good idea, though. Makes your R-12 system virtually leakproof.

R-12 is still available; it's just ridiculously expensive compared to what it cost when our cars were built. Costs $150-200 locally to get a car charged with what used to be four bucks worth of R-12. Nevertheless, there are times when it just doesn't pay to cheap out if you want good results. I never skimp on things like parachutes, motorcycle tires, or bear hunting cartridges. Having an A/C that actually cools is more important than saving a few bucks to me.

Our feeble Volvo A/C's need all the help they can get. I love RWD Volvos, but the A/C systems are an "in spite of", not a "because of". It doesn't get particularly hot in Sweden, and I get the feeling that they just tacked on an A/C system at the last minute for the American market. They obviously didn't give it a lot of thought : Why else would you have nowhere to hook up a gauge set but the back of the compressor? Or an auxiliary fan that doesn't come on whenever you switch on the A/C like most cars, but instead only comes on if the engine gets hot or the high side pressure exceeds a safe limit? (Check out a wiring diagram or read a shop manual if you don't believe this - I don't care how your Toyota works) Consider the stupidity of putting the connections for the hoses going into the evaporator on the inside of the car under the dash, rather than on the engine side of the firewall where they might actually be accessible. I've always believed that they pulled the odometer design crew off the job and put them in the A/C department. These systems need all the help they can get in coping with our southern heat/humidity situation; don't harelip them further by using a refrigerant they were never designed for.

Your mechanic is headed in the right direction as far as trying to increase airflow over the condenser. This is a major weak point in our cars, and is the reason that we get such lousy cooling at idle and in traffic even though we may be comfortable at 40 MPH.
I've found this product to be helpful:
Volvo Tropical Heavy Duty Cooling Fan Clutch

 

To Joseph, thank you for your informative and witty reply. You are on the same page as my mechanic. He did explain pressure differences related to the size of the condensor. The problem is evacuating my system of the r134 oils that were put in, and he has gotten some r12. I did install a pusher fan, so its all set to go. I just hooked it to a manual switch via a relay. You're right, the AC design was done obviously as an afterthough by the odometer crew. The only thing they didn't do was run the cooling lines through the rear liftgate hinges with the other wires.

 

I recall awhile back reading a article by a former Volvo USA corporate dude who described inviting all the Volvo VeePs on a US tour, and sending them through the Texas panhandle and Oklahoma in July or August in 240's... the next year they introduced A/C. It still took til the later versions of the 740/760 to get it right.

 

A big help on an AC system that's been converted and is somewhat average is to run the front electric AC fan whenever the compressor engages. Or if you don't have a front AC fan, fit a 12" electric fan in there, run it via a relay off the AC clutch wire.
This is a great mod on vehicles running an engine clutch fan and no dedicated AC fan, very noticeable improvement at low speeds in particular.

 

That's a great trick. I did mine last year and hooked a relay into the fan circuit from the rad. So when I turn the compressor on the front elect. fan comes on. I had also replaced all but 1 of my hoses . I replaced the compressor 2 years ago. The system blows 40* from the center ducts and I only need to use the 1st fan speed.

 

One of the beautiful things about R-12 is that it mixes with ester oil, PAG oil, or mineral oil, so theoretically if you're converting back to R-12 you shouldn't have to flush. The reason they want you to flush the system when you go to 134A from R-12 is that it will not mix with the mineral oil in the system. I did flush mine when I went back to R-12 because I had no way of knowing how much or what kind of lubricant some amateur converter had installed. Probably what your mechanic is thinking. You're gonna be a lot happier with the R-12..

 

That trick sounds useful in getting more cool out of the newly upgraded 134a system I have in my 1992 240. Does anyone have a link to somewhere with instructions? I'm not mechanically inclined (or at least not knowledgable) enough to just dive in without help.

Likewise, is it something if I asked a mechanic at my local shop to "put in a relay from the AC compressor to the front/grille fan, so the fan runs when AC runs" he'd know what I meant?

Of course, I'm not quite certain that fan is activating properly right now, when the engine gets hot. Doesn't always turn on, though it does SOMETIMES. I understand it to be a "check the coolant temperature switch for the fan" issue, but haven't gotten to that yet. So maybe I need to fix that first, so it works to spec.

 

most of the 240's had a mechanical fan that was driven by belts on the engine. it was the later 740/940s that came with an electric fan on the radiator instead. I believe what these guys are suggesting is retrofitting an electric fan onto your 240.

this is an early 740, I think, with the mechanical fan, its pretty similar to your 240


and here's a couple versions of the electric fan, top one is from a 1991 740, bottom right is 92+ 940 (and there's no clue what the bottom left is from)




ooops. 240's from about 90+ may have had electric fans, they look something like the top one on that 2nd image, but with different mounting hardware/brackets.

 

All you need to do is buy yourself a PUSHER aftermarket electric fan with mounting kit, fit to AC condenser behind the grille, then wire the fan with a relay into the AC clutch circuit.
Of course, if you can find an electric fan from another Volvo that will bolt in, you can use that too.
Fitting the fan is easy enough with instructions usually provided and an auto electrician could have the wiring done in an hour if you aren't confident in doing the job yourself.
My 90 740 had (or had) an engine driven clutch fan AND a front pusher fan that comes on at a certain temperature.

 

Thanks, Pierce, Typhoon. The second diagram is indeed the fan I have in front of my 240. That mounting breakdown really helps. I couldn't find all the connections by sight.

However, while I'm more than comfortable doing mechanical replacement/deconstruction, I've never really done any wiring work beyond my in-dash stereo. Not quite sure I should attempt installing relays and wiring from the fan to the compressor circuit, since I'm not even sure where most of the connections are. Aside from the one for fan, which is pretty obvious on sight.

I'll ask around at the shops here. See if anyone can do it quick and cheap.

Or, maybe someone knows of an online source for wiring diagrams for the part concerned here?

 

It occurred to me: would the relay/compressor integration of the fan circuit cause any issue with the existing "when coolant gets hot" temperature switch that is supposed to currently start the fan? Should that switch be disengaged if this mod is done?

 

there's a complete wiring diagram for an 85 240 available on the k-jet web

http://www.k-jet.org/files/greenbook...985_PRELIM.pdf

your 87 should be fairly similar in most respects.

you can get these books from Volvo for every year car, they are generally quite accurate.

 

if you hook it up right, the fan would run if EITHER relay triggered. just put the switch contacts of your new relay in parallel with that existing one.

 

ok, I really shouldn't have posted a 740/940 fan here, it was just what I had handy. HERE is the optional electric fan on a 87 240...

 

Wire your relay so the switch side pin 30 goes via a new 2.5mm red wire you run to the + terminal under the hood (thats right off the battery), and normally open pin 87 goes to the RED wire on the fan motor (which also goes to one side of the thermostat switch on the water pumping, part 19 in the above picture).

Then, the relay coil side pin 86 goes to the black wire to the compressor solenoid (other end of this wire connects to ONE of the green wires off the A/C pressure switch), and relay coil pin 85 goes to ground.

this way the relay is closed when the compressor solenoid is energized.

 

Pierce, you rock. Thanks. Though it's a 1992, not an 85/87. Doubt this'll make much difference.