I was wondering how difficult these are to use. I would much rather spend $200-$300 on a machine from craigslist than pay a guy the same to charge a system. My compressor came loose and the fittings at the compressor now leak. I can change the o-rings easy enough but I hate to pay somebody to evacuate and recharge the system. is there an easy way to make sure a used machine is functional?

also, for an 82 300cd, whay seal is provided at the pump? are these o-rings or will I need new lines?

Thanx

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1982 300CD Turbo (Otis, "ups & downs") parts for sale
2003 TJ with Hemi (to go anywhere, quickly) sold
2001 Excursion Powerstroke (to go dependably)
1970 Mustang 428SCJ (to go fast)
1962 Corvette LS1 (to go in style)
2001 Schwinn Grape Krate 10spd (if all else fails)

I guess you could have the guy show you on your car that the machine you are thinking of buying is working correctly ?
Is the machine you are looking at a combo machine .. 134 AND R12 or just one of them ?

i dont have a specific one in mind but something like this. I see them all the time for 2-3 hundred

http://tampa.craigslist.org/tls/637231598.html

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1982 300CD Turbo (Otis, "ups & downs") parts for sale
2003 TJ with Hemi (to go anywhere, quickly) sold
2001 Excursion Powerstroke (to go dependably)
1970 Mustang 428SCJ (to go fast)
1962 Corvette LS1 (to go in style)
2001 Schwinn Grape Krate 10spd (if all else fails)

You do have 134a in your vehicles ?

You can probably get it at a good price....most people are not wanting to get this nitty gritty with their cars.... start low... you might be surprised at what bargain you wind up with... except I do suggest he show you both that it works....and how to work it...
I got one from one of our members.... picked it up at that Centerville get together... but the CD with the instructions was lost in the transfer... and I could not find them....
I understand that the potential for making some money exists if you own one of these... sometimes local salvage yards need someone certified to extract R12 or 134 out of wrecks that still have the system together... you might have a weekly route to salvage the stuff and give them the paperwork they need to be in compliance....

I would seriously consider this. You will be way ahead of others out there who do have to go to a shop and if you want your certification, this will come in handy. I would take it in to have it looked at however. I don't know who in your area would service these, but there are service centers in almost every metropolitan area. Here in Phoenix, ours is a company called AAPAK, for instance. If it works and just needs some TLC, I say go for it!

If it works for that price, you're doing well. Robinair is a current and good manufacturer.

I've bid on plenty of those, they don't go cheap (usually) if they work.

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Gone to the dark side

- Jeff

Seems like serious overkill for what you're trying to do. Go find an old refridgerator with no freon charge in it, remove the compressor & solder a fitting on the suction side to connect your gauges to. (If you find one that still has a freon charge, it most likely died from a bad compressor, one with no freon probably has a keak in the evaporator & the compressor is still good.) You now have a vacuum pump. A gauge set can be bought brand new from HF for $50.00 or less and a universal can tap isn't that expensive. That's all you'll need to do the job, except a leak detector, if you want to double check around the compressor for leaks.
Here's one I made years ago. Still works great & gets me down to 30" of vac on the gauges. Pump it down for at least 1 hr, shut gauge valves, turn off vac pump, observe vacuum at gauges. If it holds vac for 15 min without dropping, you're good to charge, if not you've got a leak. This will work for all A/C systems, not just 134a & it takes up much less room in the garage, not to mention, no filters or maintenance required.
Your system uses o rings to seal the lines to the comp. You can get them at any AP store, just get the ones for any early 80's GM vehicle with R4 comp.
Double check you lines to make sure they don't have any cracks from the vibration.

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82 300SD 202K
82 300SD 233K
83 300TD 340K
82 300TD 98k euro (parts on the hoof)
85 300TD 282K
83 300TD 197K

hey thats great advice, what is the fitting that you soldered on? will I need an additional hose and where can I get it? can you give example of how this home made pump is connected to the system? I guess through the low pressure port since the charge is introduced in the hight pressure side?

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1982 300CD Turbo (Otis, "ups & downs") parts for sale
2003 TJ with Hemi (to go anywhere, quickly) sold
2001 Excursion Powerstroke (to go dependably)
1970 Mustang 428SCJ (to go fast)
1962 Corvette LS1 (to go in style)
2001 Schwinn Grape Krate 10spd (if all else fails)

The home-made compressor is good advice, I may just do that instead of doing an Autozone rental of a pump if I can even find one. Plenty of free fridges on craigslist or I could go to an A/C repair shop and ask for any old compressor. You connect the vacuum pump to the (usually yellow) line on your manifold gauges, blue hose connected to low side, red hose connected to high, turn on the vacuum pump and open up both valves to the high and low side to create a vacuum to boil out moisture. I would like to know the fitting too... To solder it on, you use a heavy gauge solder around the fitting and a regular soldering iron to heat it I'm assuming?

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1980 240d
1999 SL500

Dose anyone know if this is true. I have read that ounce the Reciever Dryer is exposed to the air (as when your charge leaks out) it rust up inside very quickly (which often plugs it up) and that it should be replced.
Ditto on letting the vacuum pump work on the system for at least 1 hour. This helps to get any moisture inside to evaporate and get out of your system.

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84 300D, 82 Volvo 244Gl Diesel

I understand that it's always a good idea to replace the filter/dryer when the system is open, it's a filter after all. The dryer part is a dessicant I believe, and is useless once it has absorbed its capacity of moisture from the atmosphere.

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Gone to the dark side

- Jeff

I built one of those vacuum pumps out of refrigerator compressor also. Works very well. You can get a 134A fitting from a 134A refrigerant can and solder it on the copper pipe.

what is an r124 refrigerant can? is it the professional type cans? maybe I could get one from a repair place?

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1982 300CD Turbo (Otis, "ups & downs") parts for sale
2003 TJ with Hemi (to go anywhere, quickly) sold
2001 Excursion Powerstroke (to go dependably)
1970 Mustang 428SCJ (to go fast)
1962 Corvette LS1 (to go in style)
2001 Schwinn Grape Krate 10spd (if all else fails)

For those of us not industrious enough to build our own vacuum pump, you can get one here for $135. I bought it and it works great.

http://www.ackits.com/merchant.mvc?Screen=PROD&Store_Code=01&Product_Code=90059&Category_Code=Vacuumpump

Scott

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Scott
1982 Mercedes 240D, 4 speed, 275,000
1988 Porsche 944 Turbo S (70,000)
1987 Porsche 911 Coupe 109,000 (sold)
1998 Mercedes E300 TurboDiesel 147,000 (sold)
1985 Mercedes 300D 227,000 (totaled by inattentive driver with no insurance!)
1997 Mercedes E300 Diesel 236,000 (sold)
1995 Ducati 900SS (sold)
1987 VW Jetta GLI 157,000 (sold)
1986 Camaro 125,000 (sold - P.O.S.)
1977 Corvette L82 125,000 (sold)
1965 Pontiac GTO 15,000 restored (sold)

I assume that you have a r134A manifold gauge set.

All you need is the top from an ordinary r134A can that can be found at your local Walmart. You just cut the top off and solder it on to the copper suction pipe. Things need to be clean as I found it is difficult to solder.

But, with refrigerant running at $9.00 per can, it would be expensive to buy a can just for the fitting.