How I flushed my AC system. (1 Viewer)

[GeoRoss]

This is a real time work in progress and I've been working offline with @flintknapper and @1972FJ55 on how to do this. If seen this mentioned, but no detailed "how to".

Background, my compressor would make the occasional grinding noise on start up, but worked fine. I just assumed it was the idler. Well the AC system went down and now 2 years later I've decided to deal with it.

1972FJ55 has hooked me up with a new compressor, expansion valve, schrader valves and o-rings. I had the system evacuated and proceed to go to work last month.

I took the cooling unit out using @alia176 really good thread. My evaporator was filthy. I cleaned it with Simple Green.

The blower wasn't too bad.

Flash forward to today. I used the FSM to remove the compressor. Pretty easy. I pulled the low side line from the evaporator and the high side line to the condenser. You will need to take out the ps marker light and front grill to get the high side line. I rotated my PAIR hose to make it easier.

I removed the DS marker light to remove the dryer and condenser-to-dryer line.

 

[GeoRoss]

Now, flintnapper and Rex told me to check for debris since my compressor may have grenaded. I haven't rented the flush kit yet so I just poured some of the solvent in the high side line and blew compressed air through.

You can see the black particles. You can't really see all the flecks of metal in the there in the photo.

I back blew compressed air through the condenser and caught with a clean rag.

You can see the particles. It has air flow, but I'm going to replace it on flintknapper's advice. I could try to back flush it in place. I don't think I could do a very good job flushing in place. If I have to remove it, I might as well replace it. They are in the $130 range for a Denso.

This is where I'm at. I'm off to get a condenser and rent the flush kit and a vacuum pump.

 

[GeoRoss]

Well, no Denso condensers in stock locally. It looks like I can order one from RockAuto for $70 or $150 from Napa and the like.

The project is on hold for a week.

 

[cahill]

Bummer. Waiting for parts can be tough, but it always feels good to have it buttoned back up and running as it should. Thanks for documenting the work as well. I have a feeling I will need to be doing this as well some day.

 

[Red Merle]

Sub'ed. I will be doing this soon too. If you have the time, please share the source and cost of each part, if you found good pricing.

 

[Twinair]

The receiver/drier catches anything that may be floating around in the condenser. Flush with a solvent with a low boiling point as best you can and you should be ok. If its air tight I wouldn't hesitate reusing it. Your flush procedure mentioned earlier in the thread would work just fine. The trick is adding enough flush so that liquid comes out the opposite end. One trick you can use is to draw the solvent in one end by sucking with a shopvac on the other end. Once a sufficient amount of solvent is in the coil blow it out with compressed air or, better yet, dry nitrogen.

 

[Red Merle]

Who has canned nitrogen?

 

[cahill]

I am guessing he is referring to nitrogen tanks used for welding?

 

[GeoRoss]

The receiver/drier catches anything that may be floating around in the condenser. Flush with a solvent with a low boiling point as best you can and you should be ok. If its air tight I wouldn't hesitate reusing it. Your flush procedure mentioned earlier in the thread would work just fine. The trick is adding enough flush so that liquid comes out the opposite end. One trick you can use is to draw the solvent in one end by sucking with a shopvac on the other end. Once a sufficient amount of solvent is in the coil blow it out with compressed air or, better yet, dry nitrogen.

I think I could do that, especially if I were desperate, time or money. The amount of metal that came out though is a cause for concern. To really flush it in my inexperienced hands I'd feel better pulling the condenser. If I have to do that I might as well put in a new one for $70. It will save me the effort of flushing the condenser.

I will be checking the lines downstream of the dryer. I hope it caught everything that got past the dryer.

 

[GeoRoss]

Sub'ed. I will be doing this soon too. If you have the time, please share the source and cost of each part, if you found good pricing.

I will.

 

[GeoRoss]

Bummer. Waiting for parts can be tough, but it always feels good to have it buttoned back up and running as it should. Thanks for documenting the work as well. I have a feeling I will need to be doing this as well some day.

I exchange my tools for pruning shears. We have a city brush and bulky pick up coming so time for fighting with the oleanders and mesquite trees. I'm lucky the cruiser isn't my daily driver so it can sit.

 

[Red Merle]

I am guessing he is referring to nitrogen tanks used for welding?

That makes sense. I am still trying to find a deal on a welder that I can do body work with and I should know that, but I am teaching myself. Thanks for answering the noob question.