Ok we have got the condensor and compressor replaced. We were told the Orphus tube may be clogged. I just learned my 2002 Dodge Caravan may not use a orphus tube but it may have a Thermal Expansion valve. My ac blows cool at night but hot during the heat of the day. It's charged full. Can anyone enlighten me?

 

Welcome to DF
The techs call them expansion valves. Do you know if your van rear heating and A/C too. Thats beause if you front and rear a/c, you would have two expansion valves. They are like filters, to catch debris thats in the system.

 

no rear. just front. could this be clogged causing this not to cool as well

 

Chysler doesn't use orifice tube type AC systems. They have an expansion valve that that meters the flow of refrigerant from a high pressure liquid to a low pressure liquid. Under low pressure the refrigerant boils (or evaporates) in the evaporator and turns back into a low pressure gas on its way back to the compressor. The evaporator is where the heat exchange (cooling) occurs. The expansion valve is not a filter of any sort but can become clogged or inoperative. You could replace it as a precaution. A good AC tech would have caught that early on by checking your system pressures and or lack of cooling. The TXV may be bad but its hard to say without seeing the system operating.

An orifice tube serves the same function as an expansion valve but is much more simple and it DOES have a screen or filter that can become clogged. However, it is the job of the receiver/dryer to collect moisture from the refrigerant and to collect bits of metal or contaminants in the bottom of it. That's why it is so important to replace the receiver/dryer when ever a new compressor is installed.

Good luck

 

I'm trying to do all the repairs myself. Im not a mechanic, but I have smarts enough to figure it out. Is there any diagrams on the net that would show me where I can find out all I need to know about the 2002 Dodge Caravan A/C system. Pin point locations of parts, etc....? Thanks for the info

 

This is a picture of the front expansion valve, it is behind the air cleaner housing.



1 = high pressure transducer (sensor to measure system high side pressure)
2 = low side temp sensor (used for compressor cycling)
3 = expansion valve
4 = suction liine
5 = high side charge port
6 = liquid line

 

Thanks for the diagram. Can you give me the link to the site where you got the diagram. it seems they have good info.

 

no link but if you need more, just ask

 

please, how do i remove the rear expansion valve?
it looks like i have to take the panels off inside and remove the blower ?

 

What year do you have?