I write this as I am currently sweating in a drive thru line. Has anyone else expirenced inadequate cooling with 134 in 95*+ temps? My system is functioning normal. Would going to R12 improve cooling? Please if you live up north you don't know what I am talking about.
My electra uses R12 and even though its a little low on it at the moment it still blows only a little warmer than an r 134 system. I'm picking up an extra can of r12 and getting my system topped off and check on Friday. I recommend getting your windows tinted since it dropped the in cabin temps at least 15 degrees in my car.
Heck I live up north in Ohio and I think the 134 does not blow that cold. It comes out at 42-45* and it takes a few blocks to get it going, Like about 5 miles or more to get it to that point. This is in a small Toyota Corolla XRS. I also have it in a 95 Ford ranger and it comes out at the same temp but it gets there a lot quicker. When the Buick had its air working it came out so cold you could see it. That was with R-12, I think it came out at 38*.
I wrote an article about 15 years ago called "Life after R12". It may still be floating around. Since then manufacturers have come out with expansion valves and POA valves that are calibrated for R134 but the set of valves costs about $250. Here's the cheap way to do it. If you disconnect the expansion valve from the evaporator and look up into the valve you will see a six sided hole, this is an adjustment. Find an allen wrench that fits it and turn it clockwise and count the turns. Now multiply the number of turns X .6, so if it was out 7 turns back it out 4.2 turns. This should lower your vent temp 10 deg. or so. It's also important to be sure you have good air draw across the condenser. Do this by making sure the fan is the right size for the shroud and the fan clutch is in good working order. Air flow across the condenser can also be improved by sealing the radiator to the shroud, sealing the radiator to the core support and sealing the condenser to the core support, this way all the all the air goes through the condenser not just a small portion. I do this with pipe insulation from Home Depot, stuff it everywhere you can. I found the best idle-up system is the vacuum operated ones from the early 80s GM cars. There is an electric system that they started to use in the 60s but you need to bump the throttle to gt the idle to come up. With the vacuum system you don't need to touch the throttle, if it's set-up right you can't tell when the compressor comes on. It also helps to bump the shifter into neutral at red lights. The 2010 and newer cars do this automatically, it's in the software. With all that said there is still a chance of freeze-up at highway speeds. This problem can be solved by adding a 45 degree thermostat to the evaporator box near the outlet. GM started doing this in the mid 70s so find one of those and put it in series with the compressor clutch circuit. Hope that helps. Phil
134A does not have the specific heat capacity that R-12 does. The system requires a larger condenser and evaporator as a result. I notice the lack of cooling in my Corolla in 95+ degree heat as well. If you want to convert your system to R-12, it will cool better. But that may cost you a lot, since the charging fittings are different, and will require some big changes. It might be better to verify the system is fully charged and look for a blockage in the cooling system (weeds or dirt in the condenser, for example). Does it cool OK when you're cruising on the road? If so, it just may be that the electric fan isn't up to the task with an older(?) car. The Ranger has a smaller space to cool than a Corolla. FWIW, my '70 Chevy truck cools right down even when the system is low. That system is also meant to cool a big wagon, which has a whole lot more interior volume. I agree with Devon, let's stick with cutting the mustard.
I have a paypal invoice in my email for 5 14oz R12 cans for $175 waiting to be paid now. Cost is not a problem. I already have Ester oil in my system so lubrication is not a concern. Pull a vacuum and recharge with R12.
The fittings to connect charging equipment differ from 134A and R-12. You'll have to change them, no matter what. Just sayin'.
My R-12 systen LITERALLY blows ice crystals and smoke out the center vent when the himidity is high and ambient temps are in the mid high 80s.. The POA valve may be calibrated a little wrong though.. But that is the coolest thing..
No issue there. Remove the 134 connectors and install new schrader pins. Or as a last resort, use my R134 hoses that have been cut with R22 hose ends spliced in. :laugh: Having different connectors is a joke. I am not required to change.
I know. I appreciate the advice I have received in this thread. I ordered the R12 and I will pick up a harbor freight vacuum pump and see what happens next week. What makes me mad is that I looked for two hours tonight trying to find my R12 can tap, unsuccessfully! I have seen that thing a hundred times over the years and the one time I need it it's gone. :af: The mental image of ice crystals blowing out the center vent is better than naked chicks. Thanks for that.:laugh:
Yep. Got one coming. Probably for the best that I lost that old tap. If a rotten seal on it had caused me to loose a bunch of my new R12 I would be :af::af::af:.
