airco fill-up gone wrong?

[oakleyz101]

Hi there

I have a 2002 Volvo V70 2.5TDI

and yester i desided to let someone fill the airconditioning up

he said he extracted 250grams and filled it with new gas , a 1000grams
took about 45minutes

now today ( very hot day) i was driving for about 10 minutes with the airco full blowing, it was nice and icy cold and all of a sudden it went warm,
and i coulden t get it back cold on that drive , once home i waited a couple of hours and tried again , it worked , icy cold and after ten minutes it was warm again...
Could it be that he didn,t extraxt everything, and that now my airco system is overfilled ??
and that it shuts of do to some reason???
hope some one can help out

thanks in advance

[shorod]

First thing to check is to make sure the electric cooling fan is pulling (or pushing, depending on orientation) air through the condensor and radiator. I suspect though that the system is slightly undercharged and the evaporator core is freezing up. Was the flow of air out the vents still strong when the temp went warm, or did it maybe go warm because the air flow also decreased?

There should be a sticker in the engine compartment (may be affixed to the underside of the hood) that lists the system capacity for the R-134a. I'm used to the amount being listed in ounces. Maybe it's in grams for other countries, but see what the sticker says the capacity is and how that compares with what the technician claims he put in.

-Rod

[oakleyz101]

Originally Posted by shorod

First thing to check is to make sure the electric cooling fan is pulling (or pushing, depending on orientation) air through the condensor and radiator. I suspect though that the system is slightly undercharged and the evaporator core is freezing up. Was the flow of air out the vents still strong when the temp went warm, or did it maybe go warm because the air flow also decreased?

There should be a sticker in the engine compartment (may be affixed to the underside of the hood) that lists the system capacity for the R-134a. I'm used to the amount being listed in ounces. Maybe it's in grams for other countries, but see what the sticker says the capacity is and how that compares with what the technician claims he put in.

-Rod

hi there , thanks for the answer

your wright about the airflow being less when the air turned warm,

there is a sticker and is says 1000grams , but many cases on the net say that when the machine says it extracted it all , in real there is something left......wich could result into overpresure...... so i heard...
whats your take on this
thanks

[shorod]

If they properly evacuated the system, the only "thing" of significance left in the system would be the oil charge, and that's a good thing. What I would typically do is pull a vacuum on the system to evacuate the refrigerant and any moisture then turn off the vacuum pump. If after half an hour the system is still under vacuum you can be reasonably sure there are no large leaks in the system. At this point you are starting with effectively an empty system. If this was performed prior to recharging the system with the properly capacity of refrigerant, you should not have an overcharge condition.

There are certainly folks on this forum that are MUCH more experienced with A/C systems than me and hopefully they will correct me if anything above is incorrect.

-Rod

[oakleyz101]

Originally Posted by shorod

If they properly evacuated the system, the only "thing" of significance left in the system would be the oil charge, and that's a good thing. What I would typically do is pull a vacuum on the system to evacuate the refrigerant and any moisture then turn off the vacuum pump. If after half an hour the system is still under vacuum you can be reasonably sure there are no large leaks in the system. At this point you are starting with effectively an empty system. If this was performed prior to recharging the system with the properly capacity of refrigerant, you should not have an overcharge condition.

There are certainly folks on this forum that are MUCH more experienced with A/C systems than me and hopefully they will correct me if anything above is incorrect.

-Rod

thanks for the response again

I went to an airco. specialist today and when he emptied the system
he took out 1080gr

while the guy who filled it put in 1000gr, i had seen him give it
into the system , so he probably did a poor job of emptying it in the first place

the guy i went to today explained that on cars of 7 years or older and that have had the airco filled in a winter once experience these problems with left overs in the system wich result into overpresure
so he filled my system again with 950grams , just to be sure.....
and PROBLEM SOLVED

and for the guy that filled my system the first time.... I,ll be paying him a visit soon with the bill of the specialist!!!!
thanks guys

[jdmccright]

If the A/C hadn't been serviced in a while or has had to be recharged intermittently, it may have accumulated enough moisture to freeze up and block the orifice tube, causing the air to turn warm. Once it is turned off and the system warms up, the ice melts and it works again until it refreezes and blocks the tube again.

As mentioned, after evacuating, the system should be connected to a vacuum pump to remove all remaining refrigerant, air, and any moisture/water. The water is usually trapped by a dessicant in the receiver dryer or accumulator, but in your case it may have become saturated.

Hopefully, the second specialist suggested replacing the accumulator prior to vac pull down to provide fresh dry dessicant. Otherwise it can take a long time to achieve complete evacuation as the moisture is released during pull-down, and after 7 years it can begin to break down and get carried through the system.

I'm no expert either, so chime in. If you want to learn about it more, Haynes has a manual specific on how to diagnose and repair A/C systems...also helps with converting old R-12 to newer R-134a. I found it quite helpful and not too technical.

Hope this helps!