just for comparison, what kind of output temps are you guys getting on your R-134 converted systems?

I'm not sure I'm getting mine properly charged. can instructions say 25-45psi, but is this with the the a/c running, or even with the system off?

vacuum comes down to 30" and holds no problem, but my output temp is only around 65 degrees, at best, with ambient air temp of 85 degrees. I've heard that the system is only supposed to produce a 20 degree drop, but I think something's wrong and I wonder at the proper charge. I hear people talking about getting high 30's and 40's output at the dash at idle with the doors open.

I should clarify that that's 64 degrees at idle with the doors open, set to max cool (recirc), and the fan on 2 or 3.

if I drive around slowly at say 25mph or so between 2000 & 3000 rpm, I can get it down to about 52-54 degrees with the windows closed.

while charging, there are bubbles in the sight glass, then no bubbles, which is supposed to indicate proper charge. I suppose it's possible I may be overcharged.

again...
R-134 retrofit kit refrigerant specs say the system is properly charged when the low pressure side (suction) is between 25-45psi. is this with the system running, or even with the a/c off? I think I'm only getting around 30psi with the system running.

On my home inspection report, they checked that my house AC temp diff was 14 to 20 deg below ambient just for comparison. So your 20 deg delta sounds pretty good to me. If you look on ackits.com they recommend that you go with a bigger condenser for retrofits. You could also check that your condenser is clean so that you get more efficient heat exchange, and also I have always been under the assumption that flipping the switch over to recirculating would produce the coolest air since you were cooling the same air over and over.

Aim for 30-35 psi at idle with the a/c on.

20* drop is not as cold as others, but remember... Most of these reports are coming from 4Runner owners. We already have an aux. condenser in front of the radiator.

Maybe you could retrofit an old 4Runner's condenser system into your truck? You can't buy the aux. condenser new anymore, but you should have little problem finding a used unit cheeeep.

BTW: I get about a 35* drop out of my 87 4Runner at idle. It can cause dew to form on the outside of the windows when it's below 90* and humid out (only in rainy weather or at dusk/dawn).

When it is in the high 80's I get low 40's air coming out at the vents. Although the truck is black and when much above high 80's the system just makes it OK, nor as cold as I would like. If I remember correctly I think I was 35psi or a little above that. (87 4Runner 22re)

thanks for the info so far, guys.
your reported output temps -- are those ballpark estimates, or have you guys actually put thermometers in your vents? trying to be as empirical as practically possible for consistent comparisons.

any additional information about your retrofit process you feel comfortable sharing is greatly appreciated.

Yes I put a thermometer in the vent, no I don't remember the number. But in both cases of doing R134 conversions on older Toyota trucks, I could get it cold as heck.

Fox -- did you do your own conversion or have it done?
if you did it yourself, would you care to elaborate on your process?

also, when you say cold as heck -- is this right away, or after some driving?

it's getting warm around here now. if you have access to a thermometer, would you post some before & after numbers, please?

yesterday, after driving around for about 20 minutes, I was able to get down to about 52* output. I do recall last summer, after installing the flexalite mechanical flex-fan, getting down to around 47* on my way home, I think, after some highway driving. I take the fan off when the weather cools down though, and swap back to the stock one. the flex-fan's too loud for my taste. I think I might reinstall it for the season. that certainly make a case for the importance of proper condenser cooling.

cory, you mentioned that ackits recommends going with a larger condenser -- is this typically a fabbed option? they don't list different sizes for my app.

Check out the parallel flow condensers...

ac kits condensers

so they're a generic type?
good idea, but I'll have to have a closer look at our mounts. I don't mind trying to mount a condenser; it's the plumbing I don't want to mess with.

I dropped off my old second vehicle at the shop this morning for the 134 retrofit. we'll see how it works out. on the way back into the office, I put the thermometer in the vents of a friend's car -- 38* at its coldest. way better than my struggling 54* after 20 minutes of driving.

I've done it myself, several times.

The cheap, easy & effective way is to just vacuum pump down the old system, and charge it up with the $35 kit you get at Walmart and the like. It works.

The more difficult but appreciably quieter route is to disassemble the compressor and suck the whole system of oil. Then use a "proper" R-134 oil and recharge. I've done this twice now, and it was very noticable the change in compressor noise. But it's a tedious job.

The trucks all would cool poorly if the system was low. Be it R-134, or the older R12. Being ever high tech, I would throw a can in, and be satisfied. The wifes car was/is low enough that I might throw a second can into it.

None of them cool as well at idle as they running down the road. The compressor is spinning faster, and it cools better. But set up correctly, all of them were quite cool sitting in traffic, 100+ degrees, baking in the sun.

Is yours idling up the engine enough at idle to compensate for the load? And does yours have that control unit that frequently cuts the compressor out at idle? The earlier Toyota trucks were infamous for having no cooling at idle because of this.

I've played with my fancy manifold, read the gauges, made notes, and it got me nowhere but more confused generally. Bottom line for me is, is it cold? I don't care if my gauges are reading wrong values, is it cold?

I have noticed that the R-134 converted systems are more sensitive to a loss of refrigerant, and seem to require a higher overall pressure than they are supposed to need. But that's observed without a whole lot of experience.