Why Flushing AC Systems Doesn't Work

Scotty Kilmer, mechanic for the last 45 years, shows why flushing a broken AC system often does not work on modern cars. They've made the passageways inside the system so small, that flushing can't push crud or metal particles out anymore. So if your AC compressor blows, it's a good idea to replace the AC condenser, not just try to flush crud out of it.

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5. Common Sense

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[scottykilmer]

Things I used in this video:
4. A penny
5. Common Sense

🛠Check out my Garage to see what I use every day and highly recommend:

❗️Check out the Scotty store:

👉Follow me on Instagram for the latest news, funnies, and exclusive info / pics:

[scottykilmer]

changing the expansion valve is always a good idea.

[JustAlanIsCool]

I can't agree more with this video. Took our 99 4runner, after I replaced only the compressor, to a local shop to have it recharged. Worked amazing for about one week, then nothing. I got to looking and found the line going directly from the compressor to the condensor was hot, but the condensor and other line were ambient temperature, telling me there was a clog at the condensor. Knock on wood, I don't think any real damage has been done but it none of the freon leaked out and the clutch would engage and run as normal when the button was pressed. I'd think the blockage would build up pressure and the pressure switch would see that and disengage the clutch but who knows.

Took it back to the same shop and they tell me all the freon leaked out from the compressor and it needs another one. Didn't specify where it leaked from (internal seals, housing, line fittings, etc). In hindsight I would've went with a new condensor, but at the time didn't think it needed it. O'Really's also said for the compressor to be warrantied that I'd have to buy a condensor and evaporator. I thought that was hogwash...the condensor part. Made a fool outta me. Thanks Scotty for the breakdown on the condensors!

[recoveringnewyorker]

Thanx Scotty! Shep here.You might remember that I don't charge for my labour (or I charge a very reduced rate if they can pay))when I fix cars at my Synagogue. Now I have proof that I'm not fibbing when I tell my congregation members that the condenser needs to be replaced along with the compressor and receiver drier.Some people say I'm crazy not to charge for my labour.But my waistline shows I've had a lot of good meals (Kosher of course) from gr8full people.Your vids are a G-dsend! THANX!

[killabee]

This man just don't talk the talk he shows you the proof. Great video !!!

[RagingMob]

Scotty, you inspire me to become a better mechanic and not just an over glorified parts changer. Diagnosing problems is a lost art in auto repair. Too many guys in my shop come through acting like they are an experienced tech and they just make things worse and blame the car.

[gocuexu]

Whether you like this guy or not, he is honest and to the point. Thank you Mr. Kilmer for putting on a channel worth watching. Great knowledge and explanation.

[scottykilmer]

Yes, other parts can be flushed if needed. But really, only the condenser and drier generally ever get metal pieces in them when the compressor blows, you'd only need to flush the lines going to those parts.

[scottykilmer]

the evaporator has much bigger holes in the tubes, plus rarely does metal make it that far, it gets stuck in the expansion valve or condenser instead.

[scottykilmer]

they made those so cheaply you just have to replace the entire line assembly when the valve goes bad. Great Chrysler engineering.

[rvscootin]

Since my cars are older I never would have thought about the newer thinned condenser coils. Thanks for the great video.

[HenrifyYourLife]

I love it when you do videos like this. c: They're short, informative, and involve some sort of "preventative" maintenance. That's the best kind of car repair. Haha, keep it up, Scotty!

[sneekysmurf]

Scotty you are the go to car God bud thank you on behalf of many and on behalf of my late best friend that pasted away, R.i.P Phil, he also was a car's man's man❗️. Thank you I will get a new condenser with bigger holes. P.s you are the man

[elkillerx]

Glad I watched this. I was thinking of using some A/C stop leak to fix a tiny leak I had but looking at that condenser it seems like it would clog super easily. Oh well. Just another reason for me to fix my a/c the right way. Thanks Scotty!

[eltrouble]

Hey Scotty. It's also worth mentioning that it also pays to replace the expansion valve or line filter if there's any crap in the system. Any debris that gets past the condensor usually ends up trapped there too.

Agree on the whole flushing the system thing. The only exception is if you want to be sure that the evaporator and A/C lines are clean of any debris. The flush is somewhat useful there, but I find that compressed air is usually fine in those situations.

[scottykilmer]

if ac works, condenser can last forever, it has no moving parts after all. Old ac systems should just be inspected for leaks every so often, and fix any leaks before something serious happens. Otherwise, car ac is a sealed system

[workonitm]

Agree 100 %. The condenser was probably the root cause of the compressor failure. Always replace both.

[kavanhorn]

Scotty,
It's just silly to imply that modern cars are in any way inferior to their predecessors. Pre-1980s (or so) cars were basically disposable at the 100K miles mark. Today I own 6 cars, all of which have over 100K miles, and all of those are highly reliable. I've never replaced an alternator or starter in my '06 Nissan Frontier that has over 190K miles on it while on the late 60s through late 70s cars I drove and worked on as a kid those parts were replaced regularly.

Love your videos overall, but looking back at the "glory days" of automating is pure fantasy. (This is not to say that there aren't many cars from an earlier time that I don't lust after, but they were in no way more reliable or of a higher build quality.)

[Vinnybrain]

I too just replaced a rebuilt comp I had put in my 94 astro van 5 years ago. It eventually failed, from leakage. Went with Scottys info-that if a comp is just leaking, and when you pull it and drain its oil you DONT see any metal flakes in the oil--a flush MIGHT not be needed. I put the NEW comp, 8ozs oil, hoses, accum, and orfice.pulled a vacuum all nite, closed off valves for 3hrs and checked-YaY NO LEAKS! Charged EXACTLY the 32ozs freon and It Cools SO GOOD! rebuilt comp=230 New=280. GO NEW!!!

[henrikaleksandernilsen]

These products are made cheaper and cheaper. And yet, they're expensive and break more often, and you as the car owner will gets the bill.