Author Topic: how to charge aircondition? (Read 2188 times)

85 4runr · « **on:** Nov 16, 2006, 03:36:53 PM »

does anyone know which side to add freon in the compressor on an 85 runner?

TRACKER · « **Reply #1 on:** Nov 16, 2006, 03:55:34 PM »

low side ....

Hottrod81 · « **Reply #2 on:** Nov 16, 2006, 04:06:01 PM »

Where are you going to find freon? You'll probably have to convert it unless you have some saved.

Willy Mammoth · « **Reply #3 on:** Nov 16, 2006, 04:08:50 PM »

Yup, the low side. Question is, is the system low or out of refrigerant? And where is the leak? If the system has run in a vacuum and the leak is on the low side it will have air and moisture in it. If it is R134a it would be best to change the oil and pull an evacuation (after fixing the leak) before charging. Excessive head pressure can result from air and moisture being in the system. This will also cause a restricted metering device and compressor damage.

So by just adding gas you are only biding your time till something major goes wrong.

I am EPA universal certified HVACR tech 801 and 802, but seems Joe public can buy R134a over the counter without a license.

One more thing is if the system is R12 you will have to convert to R134a which means changing the oil type and the hoses.

Note that R134a has a smaller molecule size and will leak faster through the same size hole. This is the reason for the hose change.

This would be a good time to have a leak check done before making repairs so you know what you are looking at.

85 4runr · « **Reply #4 on:** Nov 16, 2006, 06:18:26 PM »

Thanks for the info but which is the low side the one that goes into the cab or the core? It has worked good for the last three years but went to run it today and the compresor would not kick on my neighbor has all the stuff to do it but questioned which was the low side

Willy Mammoth · « **Reply #5 on:** Nov 16, 2006, 06:35:01 PM »

You will see a H & L on the compressor. If you follow the lines to the fitting you will know. Not sure on the model you are working on so this should help you locate the proper fitting.

One of the lines will go to the condenser in front of the radiator. That is the high side. The other one will go inside the cab, that one is the low side. You should watch both sides with the gauges and make sure you don't over charge it.

Here is a PT Chart to help you out. You want about 20* to 30* above the outside air temp for the high side.
The pressure will relate to temp, by using this chart you can figure out the temp by pressure. I am guessing you want about a 35* to 40* evap temp and what ever is 20* to 30* above ambient temp for the high.

Note that if you have a TXV system and I think you may it will control the low side pressure. So you want to be careful not to over charge. Watch your head pressure and make sure it don't go to high or you could pop a hose.

http://www.aircondition.com/pressure.htm

Anymore questions?

79coyotefrg · « **Reply #6 on:** Nov 16, 2006, 06:38:14 PM »

hey Mark, can you use the vacuum from the trucks engine to evac the system???

Willy Mammoth · « **Reply #7 on:** Nov 16, 2006, 06:44:16 PM »

Quote from: 79Coyotefrg on Nov 16, 2006, 06:38:14 PM

hey Mark, can you use the vacuum from the trucks engine to evac the system???

That is a good question. I guess you could, but not sure how strong of a vacuum it will pull. 29.9" of mercury is a perfect vacuum. The low side gauge should read to 30", but without a micron gauge you will never know for sure. Not critical for this type of system.

I think you will only get 15" from the manifold.

kneedownnate · « **Reply #8 on:** Nov 16, 2006, 08:19:47 PM »

They used to have several pounds of r12 where I work, and twice I filled my system. My boss didn't care cause he thought my system couldn't possibly use more than .5 lb or less :grin:

Willy Mammoth · « **Reply #9 on:** Nov 17, 2006, 04:44:18 AM »

"De minimus"

insane04 · « **Reply #10 on:** Nov 17, 2006, 06:43:06 PM »

i got 60 lbs of r-12

kneedownnate · « **Reply #11 on:** Nov 17, 2006, 06:47:50 PM »

Puff puff give!

insane04 · « **Reply #12 on:** Nov 17, 2006, 07:16:09 PM »

you got a hose to go all the way to tennessee? or you can come get a little

Willy Mammoth · « **Reply #13 on:** Nov 17, 2006, 07:23:38 PM »

You will have to keep it for your own use or find some other place to pawn it.

Unless you have a license to distribute or handle it I would be carefull talking about it.

Lets not go there again.

insane04 · « **Reply #14 on:** Nov 17, 2006, 08:37:44 PM »

got the MACS certification so no prob.

thanks

NeverEnough188 · « **Reply #15 on:** Nov 18, 2006, 01:33:34 AM »

since we are on the topic of air conditioners. i bought my truck a few months ago and it doesnt have the belt on the ac compressor. the compressor spins, but not smoothly. i know this isnt normal. but could it possibly work?

also what is normally charged to convert from r12 to r134?

Willy Mammoth · « **Reply #16 on:** Nov 18, 2006, 06:09:13 AM »

You need to change the compressor for one with the propper oil and if you have an expansion valve (TXV) system the TXV should be changed too. The hoses are a differant type for 134 and you need to flush out as much of the old oil as you can.

Unless you need to change the compressor it may not be worth the expense. You could drain the oil and put the correct oil in but this is not recommended for long term as the mixing oils will cause problems.

I doubt they are still allowing any in term refrigerants like Hot Shot for automotive use. We use R416a to replace R12 in refrigeration use, but it is not approved for automotive use. Mainly because it is a blend and needs to be charged in liquid state or the blend will change.

insane04 · « **Reply #17 on:** Nov 18, 2006, 07:52:58 AM »

if you know someone that knows waht they are doing you can use PROPANE. DO NOT TRY THIS IF YOU DONT KNOW WHAT YOU ARE DOING!!!!!!!

Willy Mammoth · « **Reply #18 on:** Nov 18, 2006, 08:58:59 AM »

Bad Idea, There has been plenty of cars catch fire because of that.

NeverEnough188 · « **Reply #19 on:** Nov 21, 2006, 01:32:57 PM »

hmmm. my compressor from my s10 is just sitting around. i could probly swap over to a v belt clutch and just use that with some custom brackets. now i wish i wouldnt have thrown away all the rest of the ac crap from that truck....

85 4runr [OP]

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