Not blowing cold air

[1BadBowtie]

Just got my AC serviced. New Compressor, filter and recharged all with new refrigerant. It takes the system forever and a day to blow somewhat colder air at the best. What could be the deal? Thanks

 

[JAW's]

There is an orafice (filter type deal) that sits inside the air conditioner line just off of the condenser. It is very common for these to clog on our trucks. If they did not replace this simple <$2 part than this could very well be your problem.

 

[1BadBowtie]

Is that something I can replace myself or does the whole system have to be emptied out..

 

[JAW's]

The entire system is eptied in the process. It is in the main air conditioner line.

Did you redo your system or did someone else?

 

[1BadBowtie]

Someone else did

 

[JAW's]

Well with a full system your going to want to find someone who has a machine that can suck out the refrigerant, replace the oraphace, and then put the refrigerant back into the truck.

 

[Toms94z71]

I agree with the orifice tube, make sure it was replaced. If they didn't vacuum the system properly, trapped air will make it slow to cool, or not want to cool at all.

 

[SAATR]

I would have somebody put some gauges on it before you go to the trouble to evacuate the system and pull the orifice tube. With a plugged orifice you should see the system simultaneously build very high pressure on the high side and pull the low side down to a very low pressure (less than thirty PSI) very quickly. Often, in a properly charged system with a plugged orifice you will see the compressor cycle very quickly and cool very poorly, as you have very little refrigerant flow through the metering orifice (orifice tube/expansion valve) to pull heat out of the evaporator and cool the air. It acts much the same as an overcharged system, which will peg out the high side pressure and hit the high pressure switch before the low side can draw down low enough to provide proper expansion of the refrigerant to cool.

The other end of the spectrum is the system in which the compressor runs continuously with poor cooling. That is usually indicative of a low charge, bad compressor that is not building good system pressures, or an otherwise good functioning system with an inefficient low pressure heat exchanger (read dirty evaporator core, in this case). Again, a good set of gauges goes a long way to finding your answers, and a good tech that knows what they are doing is invaluable when diagnosing AC issues without just going for the shotgun approach. A thorough cleaning of the evap core and case will fix the issue if it's simply plugged. The other issues you would need to take up with whomever did your work. If they were worth their salt (and many aren't) the orifice should have been replaced and the system flushed, thoroughly. Oh, and the parallel flow condensers (bar and plate, not tube and fin) can't be effectively flushed and should be replaced when the system is serviced. That said, most folks don't replace them and have no issues. A shop, however, should have at least recommended it as most manufacturers require that for the warranty on their compressors. If they didn't replace it and didn't flush the system, it is possible that the orifice is plugged. That would also be on their heads, if they did not recommend replacement of the condenser. Just food for thought!

Edit: Good example of a plugged orifice tube, taken from a Ford a few days ago:

You must be registered for see images attach