A-C issues

[dpuckett]

I posted on the other sites as well about this, so some may be repeated stuff.

I have been having troubel getting cold air from my AC this summer. I dotn especialy want to have a mobile meat locker, but 40drop would be nice. I got a new drier and installed it, but my MO upbringing got in the way, and I didnt get a new expansion valve . System had been opened with the IC install and drier installation, and I blocked off the ends with some fuel system plugs I'd had, so air wasnt circulating around in there. Got that evacuated, and installed some Duracool, which is supposed to be the best thing since the EPA took R12 off the shelves. I initally had 20psi low/ 160psi high (or so, it was 2-3wks ago), and thought maybe it wasnt getting enough pressure to do its thing, so I pumped it up to 200psi high, which gave me about 34-36psi low, bordering on too much. Vent temps are cool at best, and on an 85 deg day in stop and go traffic, I am better off with the windows down.

It cools Ok going down the road, but warms up as I get to a stop light.

Fan kicks on after about 2min stopped.

Siting in the driveway at 11-1300rpm, the evaporator does NOT get real cold- nowhere near icing over. Evap has no leaves or junk around it. Just not cold.

Could my condensor being behind the intercooler be a contributing factor? Though 1stGens with the Banks kit had an IC in front of the AC, right? Or did they? CShafer?

What else could be an issue? Is there a way to flush the AC system like the cooling system, without taking every component out and cleaning it individually? I am about to the point of saying "it's the best it is going to get, live with it." I have crossed the breakeven point with doing it this way, vs having the shop do it "profesionally" for $60/hr (SE MO half a$$ing), not to mention the time I've wasted trying to polish this turd.

Any ideas or avenuse I have not considered are appreciated. If anyone has an AC evacuator, bring it to SOP.

Daniel

[Begle1]

You could try cleaning out the condenser fins, maybe... I've heard of people saying that electric fans help a whole bunch for the air conditioner temps, so that would lead me to think that the condenser is a weak point.

I don't really have any experience with A/C at all, not since I took it out as soon as I bought my truck so that I could go faster.

[KTA]

I would suggest recovering it and replacing the expansion valve, it also could be you have too much restriction in front of the condensor causing your low side pressure to go up. You are probably also low on refrigerant, how many lbs did you put in? I am not familiar with the duracool, but the R134 jobs I have done on these trucks at say 1500 rpm sitting still on a hot day90+ with the proper lbs of charge I often times see pressures of 275-325 on the high side and 30-40 on the low side. Using an infrared gun my usual vent temp is about 50deg. As a test if the condensor is the problem you can douse it with water and see how it cools, your pressures should drop dramatically and it should cool alot better, if it doesn't you have something else wrong.

[PToombs]

DP, the more air you have over the condenser, the better it cools. On the stuff at work, it says you should have 40* at the vent at 1500-1800 rpm. I had a loader that put out 52* at idle. When I backed it out of the shop, it dropped to 40*.

[dpuckett]

Thanks guys.

First, how does one go about recovering the refrigerant without going to a shop? I have about 12-15oz of stuff in it. For 40oz of R12, it recommends 12oz of Duracool. I am not sure how much I have in it, weight wise. Is there anything else that can happen if I put a little more in there? I know there is a point of diminishing returns, but when one gets to that point is the question.

I tried the water in front trick, and if it had any effect, it didnt last long enough for me to go around to the cab. I had considered the condensor location being a culprit. Moving it would mean half a day's worth of refabrication for my IC mounts, plus possibly having to evacuate and recharge the system. But, it will be fall soon, and I do have SOME AC function, so I may just live with it for now.

DP

[PToombs]

You have to have the equipment to recover it. Can't do it at home, unless the GF brings a unit home for you. If you didn't measure it going in, you don't have a clue how much is in there. Not enough, won't work, too much, won't work! It might be a good idea to have it evac'ed, then have the proper amount put in. Then you know how much is in there.
I've been there, on that loader. I went and added some, then more, wouldn't work. I think it was overcharged. I sucked it out, and filled with the right amount. Then it worked good. (At 1500 rpm)