A/C Recharge '99 v70r

KEWROCK · Post by **KEWROCK** » 18 Apr 2010, 11:48

Hello Forum.

1999 V70R T5 AWD

Compressor cycles on and off about every second in park. No Cold air. Been like this for about 10,000 miles.

I bought a can of freon(or134A) with the gauge on top. The gauge is fluctuating from 10psi to 70psi with the cycling of the compressor. won't take any freon.

I only find one connector marked "6nM". I'm assuming this is low pressure because it matches the fitting on the hose.

Any help, greatly appreciated.....Rocco

Post by **stone36** » 18 Apr 2010, 11:59

the fluctuating from 10-70 probably means the the compressor is turning on and off, but there is not enough refrigerant in the system to keep it on. When these pressure in the system gets too low the compressor will kick off as a precaution. Just keep that bottle upside down and all the way open until the pressure starts to even out. Eventually you will get enough in there to keep the compressor on and it will keep taking the charge. If your system pressure is at 10, you will probably need more than one can, though one will probably get it at least "cool" again, but maybe not cold.

There is also a thread on here that I added a picture and description of how to "jump start" the compressor to make it take a charge.

Post by **matthew1** » 18 Apr 2010, 13:01

Further a/c recharge reading

More further aircon recharge reading

Post by **JRL** » 18 Apr 2010, 13:18

Also stick the freon in a pail of warm water.
Stuff is so cold at times it does not want to go in, the water fixes this.

KEWROCK · Post by **KEWROCK** » 19 Apr 2010, 09:25

Thanks Guys. I don't know what went wrong the first time I tried, but the second time it sucked down the whole can in seconds. The compressor immediately stopped cycling, and stayed on continueously. One large can was the perfect amount according to the pressure gauge and ambient temperature chart the can came with.

I hope I didn't shorten the life of the compressor by letting it cycle on and off for so long. At least 10,000 miles, plus however long the previous owner used it like that.

Post by **stone36** » 19 Apr 2010, 10:34

KEWROCK wrote:I hope I didn't shorten the life of the compressor by letting it cycle on and off for so long. At least 10,000 miles, plus however long the previous owner used it like that.

FWIW, mine has been doing that for 5 years and I have to keep recharging at the beginning of each season and keep topping off all summer.

KEWROCK · Post by **KEWROCK** » 22 Apr 2010, 10:03

Well, 4 days later. Still keeping the same pressure. I wonder where the original freon went? If the system was previously disassembled there shouldn't have been enough pressure to cycle the compressor at all.

Post by **jblackburn** » 22 Apr 2010, 10:12

The evaporators rust away and start to leak after so many years. I have to fill mine up every month or two. It's a looming, extremely difficult repair, but just ignore it and keep putting freon in when the cycling comes back again until it gets worse and won't hold a charge for more than a few days.

HVAC Dude · Post by **HVAC Dude** » 22 Apr 2010, 19:46

Hi Folks, 1st time posting to answer a few questions. I can get windy on this stuff so pass on it if you find yourself dozing off...

"I wonder where the original freon went?" It went into the atmosphere. All of it goes there. All vehicle AC systems leak. Some leak more than others but when the car was built it left the factory with a fine leak. It is unintentional and not part of the design; it just has to do with the limitations on o-rings and sealing technology. Now it may have leaked 10 g/yr for the last 10 years. On a 500 gram charge, 20% of the original charge would now be gone. 10 g/yr is actually a very low leakage rate that vehicle manufacturers are just now capable of getting down to and will have to do so with new EPA rules on refrigerant emissions beginning in the 2012 model year.

"I hope I didn't shorten the life of the compressor by letting it cycle on and off for so long." Lots of things can kill a compressor and each compressor type has a different failure mode. I believe our compressors are piston (not sure because I have not had the vagn that long and have not looked) and those mostly go to lack of lubrication. The refrigerant is what circulates the oil that lubricates the compressor. If you are low on refrigerant, less oil circulates back to the compressor. The compressor cycling off is in reaction to that, to protect the compressor.

"The evaporators rust away and start to leak after so many years. I have to fill mine up every month or two." Since you are replacing a can of refrigerant every month or two, you may want to add oil to the system the next time you do that for the reason mentioned above. When you have a leak the oil and the refrigerant leak out. The oil lubricates the compressor as I mentioned above and it keeps it cool. If you lose your oil, your compressor will seize. The oil is sold right next to the refrigerant cans.

Changes are coming to the DIY refrigerant market. A new refrigerant has been proposed that is "better for the environment." I put that in quotes to acknowledge there are differing views on that subject and not to take any sides. Beginning in 2013 the new refrigerant will be phased in. All the issues we had going from Freon to 134-a are coming back. Service fittings will be different and incompatible with today's service equipment. Gauge sets will need service fitting adaptors. The oil will be different too. The good news is that the refrigerant is nearly a drop-in replacement making adaptation simpler than getting a late 80s car running on 134-a. That could come in handy if 134-a undergoes restricted access as Freon did. The bad news is that the new refrigerant will not be available to the DIY market at all. Only licensed technicians can get the stuff.

Post by **Ozark Lee** » 22 Apr 2010, 19:56

The good news is that the refrigerant is nearly a drop-in replacement making adaptation simpler than getting a late 80s car running on 134-a. That could come in handy if 134-a undergoes restricted access as Freon did. The bad news is that the new refrigerant will not be available to the DIY market at all. Only licensed technicians can get the stuff.

For starters, welcome to MVS.

Beyond that I am very disappointed. Does Dupont have another patent expiring?

We have been warned, stock up on 134A now.

The licensing doesn't scare me at all but the fee to get licensed does. How much is the test these days?

...Lee