The AC on my 99 Dakota Ext Cab V6 packed it in before the hot weather. Turned out have no coolant pressure. Mechanic said the condenser is leaking. Is this something I can replace myself. I'm looking at the Haynes manual and it seems simple enough but thought I would post here to get any input. The quote I got for the entire job was $750, with the condenser costing about $250.

 

After looking at the instructions, it sure looks like you could do it yourself, with the proper tools (mainly for evacuating and charging the system).
You might want to replace the accumulator (aka drier), and orifice tube while you are at it.
After you replace these parts, you will have to do a system evacuate and recharge. You MUST evacuate the system, as if you don't, the moisture in the system, and the air, can destroy the system. When you do a system evacuate, make sure you do the vacuum test (which can determine if there is a leak)
You will also need to add the following amount of refrigerant oil: 30 milliliters (1 fluid ounce) for the condensor, and 120 milliliters (4 fluid ounces) for the accumulator. The refrigerant capacity (R-134a) is 0.907 kg (32 ounces).

 

Is it really necessary to evacuate the system? I though the only reason mechanics are pushing this procedure is because you are not suppose to release this gas into the atmosphere. Since I already have the leak, I am already evacuated. As far as moisture, the system will only be opened for a brief time so will this be an issue. I am just curious.

WarrenC

 

Yes it will be an issue. The smallest amout of open air contains humidity....which is water. It only takes that much to allow the combination of the freon and the compressor oil to develop into an acid type substance. This will destroy your seals, pipes, and ultimately your compressor. So if you feel like replacing all that stuff in the very near future, go for it. But I highly recommend getting your hands on a vacuum pump so you can properly evacuate your system before charging it.

You reclaim the freon that is in the system now, in your case, it problably all leaked out.

Most shops will pressure test with nitrogen gas (nitrogen gas lacks water) before completely evacuating the system with a vacuum pump. Some places just pump it down to 13 or 14 in/hg, and shut the pump off to see if it holds a vacuum for a certain time period.

Mechanic's push this issue because if the epa/repa found out you were knowingly spewing freon into the air, heavy fines would be applicable. Considering freon contains cfc's and/or hfc's and /or hcfc's (ozone depleting molecules that aid in giving you just that much more of a sun tan every year).

Hope this shed some light.

 

To piggy back, like erock92kota said, yes, even the smallest amount of air in the system can containmate it. And the condensor is going to have the lines just filled with air.
Vacuum pumps can be found at a reasonable price. I bought one a few months ago, its operated by compressed air, and it cost me like $10. (A picture of the box is attached below) You can buy, or probably rent, electric vacuum pumps, but their not cheap. Just go to a local auto parts store and ask about a vacuum pump, they should be able to point you in the right direction.
As far as refrigerant goes, you don't really have "freon" per say (although the term seems to be used interchangeably). You have R-134a. Freon, for example, can only be bought by EPA approved people (and its expensive on top of that), where as R-134a can be picked up by any one at their local Wal*Mart. Freon is much worse for the atmosphere than R-134a, but, R-134a can still harm it, and your not supposed to release it into "the wild," however, the EPA ain't gonna come knockin on your door just because you bought a few cans of it. (However, R-134a is much more prone to leaking because I guess its "thinner," which is why A/C systems have to be serviced every couple of years)

Bottom line: you can replace the condensor (and other parts) yourself, but it can not be stressed enough that you must evacuate the system before charging and using the system. Even if you have to pay someone to evacuate the system, it should and must be done.

[IMG]local://upfiles/948/7E510F19E12F4AECB39BFDEB102F4A01.jpg[/IMG]

 

thanks for all the "insider" information. I always try to find out why things have to be done a certain way and now I know.

WarrenC

 

If you wanted to change the condensor yourself and save on that part you could. I know at the shop I work at we only charge like half an hour ($34) to evacuate and recharge an A/C system plus the cost of freon.

 

$34 would be good. I was quoted $150-160 to do the job.

Warren

 

For evacuating, I was quoted $80.... My questions: I have had my 2000 Plymouth grand Voyager evacuated, and I vacuumed it with my pump, it's not leaking. Anyone know how much R-134 I need to add, how much PAG oil I need to add, and what are the numbers, PSI-wise, I should be seeing on the high and low side after I have recharged it?

Thanks,

Matt