2009 F150 AC debris flush (any suggestions)

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My 2009 F150 4x4 Supercrew AC compressor destroyed itself. Clearly, the low pressure lines are chock a block full of metallic debris/powder. Strangely, the high pressure side is visibly clean, although I'm sure it's also contaminated.

I've removed some lines for cleaning. But not yet the lines from the evaporator.

I'm concerned the evaporator is full of debris. I'll try various methods to flush it out, but I'd love suggestions. For those who don't know, the evaporator lines disconnect at the firewall. So I could fabricate something to flush from there.
 
Some treat it as a heater core and gently flush it with compressed air and the citric flush solution while in the vehicle, but I've read it technically needs to be taken out. I would personally try avoiding the latter.

Hook a hose up to the bottom line and run it into a container so you can catch and see whatever debris you've flushed.
 
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That's a good idea. I'm not happy about wasting a week taking the dashboard out to replace the evaporator.
 
Debris is usually flushed out of a/c parts using mineral spirits, and finished with lacquer thinner or alcohol.
 
Chris I am showing my age do people still install inline filters to catch the debris?
 
There should be a screen entering side of expansion value or orifice that should stop anything large from entering evaporator. Replace condenser is a must and only use ac flush. Autozone has the flush and the tool(loaner program) to put it in.
 
Denatured alcohol is what we used to use to flush the lines. Maybe this will work in the evaporator.

Does your a/c have an expansion valve ?
If it does, you may need to replace it also.
We never had luck flushing those out.
 
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Originally Posted By: CT8
Chris I am showing my age do people still install inline filters to catch the debris?
not as much as they used to. The special hoses and tight quarters make filters hard to fit.
 
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Originally Posted By: Cujet
the low pressure lines are chock a block full of metallic debris/powder. Strangely, the high pressure side is visibly clean, although I'm sure it's also contaminated.


Usually, it's the other way around: compressor dies and contaminates the high pressure side, requiring condenser replacement.

The evaporator almost never gets contaminated, unless the restrictor orifice is blown out.

Originally Posted By: Kestas
Debris is usually flushed out of a/c parts using mineral spirits, and finished with lacquer thinner or alcohol.


Yes, whatever will dissolve the oil used.
 
Originally Posted By: CT8
Chris I am showing my age do people still install inline filters to catch the debris?


That's the job of the receiver/dryer.
 
We do a lot of "completely blown" systems in trucks. In Florida, in the [censored] trucks, it's real popular.

Condenser is gone. Don't bother inspecting or cleaning. Just toss that thing.

Orifice tube or expansion valve is gone. Toss it.

Toss the receiver/drier too.

Flush using AC flush (most auto parts stores have it in a can, which makes it easy), then finish by flushing with denatured alcohol, and then a lot of dry compressed air.

The hoses should be fine, so long as they don't have any "mufflers" or filters.
 
Originally Posted By: DoubleWasp
We do a lot of "completely blown" systems in trucks. In Florida, in the [censored] trucks, it's real popular.

Condenser is gone. Don't bother inspecting or cleaning. Just toss that thing.

Orifice tube or expansion valve is gone. Toss it.

Toss the receiver/drier too.

Flush using AC flush (most auto parts stores have it in a can, which makes it easy), then finish by flushing with denatured alcohol, and then a lot of dry compressed air.

The hoses should be fine, so long as they don't have any "mufflers" or filters.


Thank you for the input. The compressor discharge hose has a small accumulator/filter/canister on it. I'm sure it has debris inside. But I'm not sure what that canister really is. Maybe I'll cut it apart and find out.

The condenser has the R/D located on the inlet side, internal to the condenser.
 
I did this on a 91 Caprice . It has a screen on the incoming side of the orifice . I figured if the metal particles were small enough to get past the screen & not stop up the orifice , I would not worry about the ecaporator .

I used an A/C flush that I think was essentially R-11 refrigerant . Not cheap . I would not use any of the " home brew " flushes .

Flushed the lines , evaporator & condenser ( both directions ) and replaced the compressor , the accumulator / dryer & the orifice .

I used R-134a and the oil specifies for R-134a . POE , if I recall correctly .

Best of luck to you , :)
 
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Here is a pic of the Evaporator outlet. Yikes.
 
Originally Posted By: Kestas
Debris is usually flushed out of a/c parts using mineral spirits, and finished with lacquer thinner or alcohol.

That's what I did on my old car - low-odor paint thinner and I used brake cleaner or perc to chase out the stoddard solvent.

This stuff also works good but it's pricey. I used it for the more critical evaporator - https://www.amazon.com/Four-Seasons-69991-Flush-Solvent/dp/B000E0Z6NM

But really in a modern car the condenser and evap are gone - R-134a systems call for multi-flow or parallel flow heat exchangers with tiny passages. Flushing those is strictly a YMMV procedure but there will be some residual solvent no matter how careful you are. I'd replace the evap/condenser/TXV/drier and any hoses with mufflers on them. Flush out anything that's simple straight-through with a good AC flush("pop" the components as well with compressed air or nitrogen if you have access to it) and if you can get one, a nice long vacuum with a real HVAC vacuum pump to boil off any residual solvent wouldn't hurt.
 
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A contaminated expansion valve

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I drilled out the expansion side and threaded in some fittings for the flush. An amazing amount of aluminum debris came out. So far, I've used Mineral spirits and denatured alcohol. I will follow up with other chemicals to remove any residue. I'm not convinced I can get all the debris out.

I may consider a suction side filter. I've not seen a good one that would fit. Maybe I could make one.

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Since the debris is large chunks, they will be less likely to "float" their way out on the exiting charge of solvent/air.

Don't worry about the solvent/alcohol. You will definitely need to do a looooooooong vacuum cycle. I'd recommend vacuuming overnight. Now might be a good time to pick up an HF vacuum pump.

It's going to look immensely nasty as you are flushing. Just keep it up, and don't be shy with the compressed air. Those evaporators were designed to take a lot of pressure. I have no truck with giving one a full slug of 150psi air. not like the interior is actually going to see that pressure as the air expands and shoots its way out.

For the really stubborn ones, I've taken a new HF electric leaf blower, taped the nozzle outlet closed with a load of Gorilla tape, drilled a hole, secured a hose barb of the correct size to the nozzle body, hooked it up to the evaporator, and turned it on.

You'd be amazed at what suddenly finds its way out then. But that's strictly a last resort.
 
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