a/c noise
 

06 grand caravan 3.3 130k. A/C works ok not the best so I thought I would add a can of A/C PRO . Pressure was 3/4 up in the v-spot. Added as directions said . Now psi is 1/4 up in the v-spot. Did not help the a/c any.
Why would psi drop now? Thank You.

I am not sure of ac pro but I believe those cans that say they refrigerant usually aint. they something else. most refrigerants you need license to buy. so probably mixing the 2 aint going to be good.

But why would the pressure drop if you adding? also i have had a noise like everyone else gets. At low idle a/c on, theres like a box of marbles when a/c cycles on. What do you think it might be?

Have no idea why pressure would drop if you added refrigerant unless during the process refrigerant was actually lost somehow or maybe a bad gauge on the crappy AC PRO kit. That stuff is bad news FYI and you should NEVER add refrigerant with stopleak because the stopleak can actually plug up the system and even seize a compressor. You should always find and fix the problem. They will never tell you this a the auto parts store.

Read here about stop leak - http://www.autoacforum.com/macs/sealer.pdf

As far as the box of marbles is concerned - the compressor pulley bearing is probably shot. Check here for instructions about removing the bearing and even the clutch - http://www.freeengineinfo.com/dodge-...eplacement.htm

From my experience adding refrigerant, it is very easy for it to escape as you are adding it. This is because the usual connection hose type that you use to pierce the can does not work very well. So I would suggest that you may have thought it was entering the system but it was escaping at the valve on the can, and in pressing in the valve on the a/c line in the car, you actually released some of what was already in there, and lowered the pressure! The trick to adding ordinary R134a is to put the connection on the can before you connect it to the car, and then open the valve on the can until you hear a very slight release of Freon, then turn the valve back to stop the release. Then put it on the car, and you know then when you open the valve from that point the Freon is going into the car. It only takes a minute or so for a 12 oz can to empty, and as it empties it begins to feel freezing in your hand, so use a cloth around the can.

Wow, they don't tell you that info on the can or website. The a/c does blow cold but makes noise at idle. I am gonna be driving a long round trip with no time to fix right now, so I hope there wont be any problems with that. Thanks for the quick reply.