fireram

There is a tone of info about this on the net, none seems to help me..

Background - Three years ago, i paid an ac tech to diagnose and fix my ac problems, after three vacumes, and not seeing any drop, even overnight, and after adding florescent dye, and after adding sealant, the next year it still lost its charge. So I replaced the evap core, and heater core, while I was there..

Same thing, put the vac on it over night, no drop, so recharged it, then next season it quit working again.. I drove without it for a year...

That brings us to this season.. I decided I would take it back to the ac guy and just get him to recharge it for $100 again, and cross my fingures that it would last the season.. But then the sale at parts source on the redtk recharge kit, two small cans of tk12 and a filler hose with gauge.... $40.. so I thought I would give it a try.....

Had a heck of time getting the quick release fitting on the low side,,, Cause the ambiant pressure in there was over the readings on the gauge..

So I followed the directions, opened up the can, no gas came out, started the truck,. when the pump kicked in, the gauge dropped to between 60psi and 80, after 20 to 30 seconds, the pump kicks off, the gauge then goes back to full over 300psi. When the pump kicked on again, the gauge reads around back around 60, then 20 sec latter the pump shuts off, and the pressure spike again,. This happens for about 2 min, then the pump just wont come on again. When the pump is running it is producing cool air, and the lines get cold, when the pump stops the line gets warm and the cool air gets warm. There is lots of air flow from all the vents, and the door works, it switches from defrost to full ac just fine...

In summary: After sitting for a few minutes, start truck, ac blows cold, comp cycles for about 2 min, pressure on low side goes from low of 30 when comp running, slowly climbs to around 60, then comp shuts off and the pressure spikes to over 200.

I put a gauge on the high side, and nothing,,, there is no pressure at all on the high side.

Any ideas?? Could it be the oriface is plugged and only letting a little past, enough to cool for a few seconds until the low pressure switch on the high sid e kicks the comp. off????

Thanks

badme

You will probably have to use a commercial set of gauges to fix this. R134a does some weird things. I have had several vehicles with problems like yours and all that I would do is evacuate and recharge the system and it would work fine. The new sealers work good, I would evacuate the system. Then if it still holds a vacuum after 30 minutes with no drop, recharge it. If the a/c works good add some stop leak. The gauges should be 30-50 on the low side( 30 is better), and 250-350 on the high side.

patdaly

I would verify your new gauge is reading accurately.

I have one of them things and it reads nowhere near the readings of my "real" gauge set.

I would start there.

1-2-3

I too got one of the refil kits with the little gauge. Each time you put the gauge on, mine will read diffrent. Way diffrent. I got a good set of gauges and use those to take my refrences with and use the little gauge for just a way to add some 134 to a system. it does sound like your either way overcharged or have a blockage.

Too much freon can be just as bad as not enough freon sometimes. You may also be having a pressure switch issue.

supr

Cahliez, how do you like your Airtex? had it long?

On the AC, from what I understand, those gauges on the 134 cans are useless. I have been told to just hook up a can of 134, turn on AC max, windows down, and put in what it will hold. It will blow cold, unless there is a serious problem. Seems like all these Dodge trucks have leaky AC, bad evporators. It helps to take the airbox off to get good access to the low pressure valve.

fireram

Well, after figuring I had too much in it,,, Not sure how that would happen all on its own, I put the emptycan back on it to take some of the pressure, I am stupid and admit it, of course the can dose not reseal itself so when I took it off, i just lost the stuff to the air......

So , I put the other can on, the kit came with two, started the truck, when it started pump the pressure went down, I opened the can upside down, it stopped the pressure drop around 50, and when it started to climb i shut the can off, then the pressure went above 60 and the comp shut off.. when it cycled back on and dropped below 60, I opened the can and it stopped dropping around 40, and when it started to climb i shut the can off again, again when it hit 60 the comp shut down, and the pressure spikes to 300, when the comp restarted I whent for a 10 km drive, the cool air lasted about 5 min..

I will make an appointment to see the AC Doc. like I should have in the first place, If he finds anything other than low freon I will let you all know,,,

Thanks very much for all your help...

pipergsd

The AC systems on our trucks are criticly charged systems witch symply means that you should weigh in your charge after a good evacuation and pressure test.