First off, it never had cold air to begin with so I don't have much to go off of so I was hoping that everything worked and I just needed to vacuum the system and refill. I doesn't seem that way so far, first I vacuumed the system for about ten minutes and nothing really seamed to have changed so I figured might as well move on and refill, well that didn't work either. The can of refrigerant was tapped but nothing happened, pressure built up but no gas left the can as far as I could tell (still the same wieght, and tried the hot water trick). Assuming that I followed the FSM correctly (magnetic clutch works, vacuum then refill) I must have a bad compressor for it not to give any refrigerant/moisture and not accept any either right? It looks to be about a $150 refurbished part, AWESOME! I know I will want the AC here in TX. <img src="/forums/images/graemlins/mrt.gif" alt="" />

Any thoughts or advice, Thanks guys.

What refrigerant are you using? If this system was down for a long time 10 minutes of vac is not long enough to extract moisture from the system. 30 minutes to an hour at 29.5"hg is recommended. Did you get 29.5? Usually before filling you want to close off the gauge valves to see if the system holds vacuum for at least 20 minutes to assure no leaks. If there was proper vacuum the first can of refrigerant should have gushed into the system (compressor off), if it did not then a fill valve is blocked or there is no vacuum. You haven't done enough troubleshooting yet to blame the compressor. I'd start over making sure the system is tight. I'd also recommend replacing the filter/dryer as well.

I don't think there is a vacuum, ran the pump again and it doesn't move from 0 PSI. I don't understand the 29.5? I have the PSI gauges. <img src="/forums/images/graemlins/confused.gif" alt="" /> I thinking I will take it into a shop to varify and just attempt to fix it myself.

Being it's a vacuum, how would a gauge go negative if it can't get below 0 PSI? I shouldn't have bought the gauges from AUTOZONE! <img src="/forums/images/graemlins/rolleyes.gif" alt="" />

29.5 inches of mercury is the what you try to pull on the system to boil out all the freon and water from the oil. The blue gauge should have two diff colors of markings in the outer band. I cant remember but i think the inches of mercury are marked in black usually. When you pull a vac on the system, the blue gauge needle will move into the negative area on the gauge, the black side. If you dont have those markings on the gauge, just pull a vac on the system with a vac pump and let it run for 20 mins. I cant believe that anyone would make AC gauges without a negative on the blue gauge. If you can get a vaccum pulled for 20 mins then you should close all the valves, turn off the pump, and monitor the needle and make sure it doesnt move back towards 0. If it does then you have a system leak. Then you should be able to connect a can of freon to the system and it will suck it in, actually be blown in by the pressure in the can, it will eat a can of freon fast. Remember to turn the valve on the can all the way in to puncture the seal on the freon then turn it almost all the way back out. I assume you have converted to r134. Make sure the valves on the connectors on the AC compressor are turned all the way in to depress the valves on the compressor and the valves on the gauges are turned on ( i cant remember if they turn in or out) as well. Fiddle with all the knobs everywhere and see if this helps. Take it ones step at a time again and it should work out. I have had some trouble with cheap gauges not depressing the valve on the compressor. Hope this helps.

sOUNDS BEYOND MY THRESHOLD, BUT I JUST PULLED A GOOD PUMP OFF A D50 I AM WORKING ON, ILL GLADLY SHIP IT TO YOU FOR THE COST OF SHIPPING AND FIFTEEN BUCKS FOR BEER AND PIZZA.

When you started work on the system, was there any pressure in it or had all the gas been lost?

No pressure usually says that you have a good sized leak.

I'm assuming you bypassed the low pressure switch to get the compressor to turn on? As far as vacuum and how long to leave a system pumped down, you need to get really close to a complete vacuum to get all the water out. If its warm out, the water will boil out with less vacuum. At 60?F you need to hit 29.4". It's been a while since i have looked at the charts, but I remember pumping down systems that had been open for two or more hours. On a cool day, I would run the pump for four of five hours.

Also, the AC vacuum pump should be some type of two stage rotary vane pump that's rated for this type of application. Not sure how well the ones that use compressed air work. Most pro sites say they are good for air removal but not enough to remove any moisture. On any system that's totally lost its charge it's possible the you also lost oil.

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Also, if the system lost all its charge or was open its good practice to replace the reciever dryer so that your starting with fresh desiccant.

Kevin

Well my system doesn't hold a vacuum, I'm not surprised. I returned the worthless manifold gauges with no negative HG readings to Autozone and was loaned the ones with them. Anymore ideas besides getting the dye, light and glasses kit to find a leak. Anyone ever use the UV light to find a leak? I assuming that the leak stop won't work on my system.

Also the vacuum pump that Autozone loans out is a 1.5 cfm for $200, funny how you can buy a 2.5 cfm from Harbour Frieght for $100. More and more I work on my truck I just get more and more fed up with these auto stores.

Isn't that $200 fee simply a deposit?

It was common practice for the technicians at the Nissan dealership I worked at to use the uv dye and glasses to locate leaks that weren't big enough for the handheld freon sniffer tool to locate. It's especially useful when the leak is a very slow one (not your case if your system won't hold a vacuum) since the tech could add the dye when charging the system and send the customer away knowing that he'd be able to locate the slow leak when the customer returned.

The freon leak detector (like this one: http://www.instrumart.com/products/31321/bacharach-informant-2-leak-detector) would probably be a better tool for you since you obviously have a significant leak, but I don't know if it's typically available to the general public as a loaner tool from anywhere - you'd probably have to purchase one yourself.