replacing a/c compressor

[billnflorida]

Hey all I have a question about replacing compressor. When I do this what all should be replaced and should I do the condensor. My explorer has 225000 on it and I am wondering if I should replace and do serious repairs or just say adios. By serious repairs I am not talking about any engine repairs. What is the life expectancy of the 4.0 engine in your guys opinions....thanks the fla weather is about to get mighty warm with no ac...

 

[BubbaFL]

Definitely replace the accumulator, and the expansion valve if it's not too difficult to reach (haven't done one on an Ex, so couldn't tell you where it is). I wouldn't replace the condenser unless it is leaking - just pull it out and flush it (there is some special chemical for this).

When you remove AC parts, drain as much oil out of them as you can into a container and measure it - put that much new oil into the parts you're installing, and replace all of the o-rings you come across.

Before you replace the compressor, check the accumulator - [link]http://www.imcool.com/articles/aircondition/corroded_accumulator.htm[/link]. That problem happened on my V6, and was very easy to fix (borrowed a vacuum pump and gauges from a buddy).

 

[imp]

Definitely replace the accumulator, and the expansion valve if it's not too difficult to reach (haven't done one on an Ex, so couldn't tell you where it is). I wouldn't replace the condenser unless it is leaking - just pull it out and flush it (there is some special chemical for this).
a vacuum pump and gauges from a buddy)........

In the 90s or so, Ford began using a different technique for metering the "freon" into the evaporator....instead of an expansion valve, a pressure switch was incorporated which cycles the compressor, instead of controlling the amount of liquid flow with a valve. I THINK it's still being done that way.

The accumulator, sometimes called a "receiver-dryer", contains dessicant material to absorb any moisture which might find it's way into the system. Moisture is the reason why A/C systems must have AIR sucked out of them before putting in the refrigerant material. With high-mileage and usage, replacement of the accumulator would be a pretty good idea, I should think.

If I'm "out of date" with this info, someone please jump me, as I am a theory guy more than a mechanic...... imp

 

[BubbaFL]

There has to be an expansion valve or orifice tube somewhere - not sure. Some cars it's in the engine compartment on the firewall; in others it's in the dash near the evaporator.

The pressure switch prevents the system from building too much pressure on the high side (and exploding violently).

The accumulator on some years came wrapped in an insulating blanket, that trapped condensation and caused it to rust out under the insulation and leak. If the system is sealed and holds a charge it should never need replaced, but replacement is recommended if other components are replaced or the refrigerant leaks out completely and air (moisture) gets in.