Clean AC evaporator coil (externally).

[Eurasiaoverland]

My evaporator coil, while not damaged or corroded, is caked in 30+ years worth of dirt and fluff.

I have a junk coil which is similarly dirty and experimented cleaning it with a power washer from a safe distance where it would not damage the fins, but this only got rid of the loose stuff.

Can anyone recommend a product that will shift this stuck-down dirt? I was thinking maybe brake fluid which I have used successfully to get sticky stuff off plastic.

Thanks

EO

 

[Spike Strip]

Is there a shop around that can boil radiators and has a solution safe for aluminum?

Otherwise, just dishwashing liquid (dawn) or simple green (careful with Aluminum), let it soak, soak, soak, then pressure wash (gently) is all I've ever done.

 

[OSS]

I assume you’re referring to the condenser in front of the radiator. The evaporator is inside the cab.
There’s two things going on with these ancient aluminum condensers: corrosion and dirt.
The corrosion etches the aluminum which allows it then to grab dirt and road grime and hold it. kind of like a sponge.
Your best bet is an -aluminum safe- detergent. Unfortunately regular old Green Simple Green degreaser is not recommended to be used on aluminum (says so on bottle) and it definitely etches aluminum, since I made that mistake once myself (turning shiny bright polished aluminum dull gray very quickly).

I emailed the company and they recommended a different product for aluminum.

Simple Green (the company) does make an aluminum safe cleaner. It’s purple (in the USA) and labeled as Simple Green HD. Or there’s another product, Simple Green Extreme Aircraft (which is clear). That’s the stuff I used. Definitely safe on aluminum.

 

[LA Z]

This is what I've used on mine.
It worked pretty well getting rid of the dirt in the condenser and evaporator.

 

[OSS]

Since I never used my AC ever, I decided to get rid of the gunked up and corroded condenser. I’ve got to say, the radiator worked a whole lot better without that ‘wall’ bolted in front of it blocking all the air.

 

[Eurasiaoverland]

I assume you’re referring to the condenser in front of the radiator. The evaporator is inside the cab.
There’s two things going on with these ancient aluminum condensers: corrosion and dirt.
The corrosion etches the aluminum which allows it then to grab dirt and road grime and hold it. kind of like a sponge.
Your best bet is an -aluminum safe- detergent. Unfortunately regular old Green Simple Green degreaser is not recommended to be used on aluminum (says so on bottle) and it definitely etches aluminum, since I made that mistake once myself (turning shiny bright polished aluminum dull gray very quickly).

I emailed the company and they recommended a different product for aluminum.

Simple Green (the company) does make an aluminum safe cleaner. It’s purple (in the USA) and labeled as Simple Green HD. Or there’s another product, Simple Green Extreme Aircraft (which is clear). That’s the stuff I used. Definitely safe on aluminum.

It would have been safer to assume I am referring to the evaporator coil. When I say 'externally' I mean on the external surfaces of the evaporator, as opposed to referring (in a grammatically incorrect form) to the exterior of the vehicle.

Condenser is brand new, but Toyota no longer make the evaporator for RHD models, so it needs cleaning out.

Thanks for the tip on the product, I will see where I get with dish washing liquid and then brake fluid for the stubborn stuff.

 

[Eurasiaoverland]

This is what I've used on mine.
It worked pretty well getting rid of the dirt in the condenser and evaporator.

View attachment 3220994

Thanks. If I don't get satisfactory results with dishwashing liquid/brake fuid and power washing, I may see if anything like that can be found locally, but I somehow doubt it. Any idea what's in it?

 

[Spike Strip]

Toyota *did* sell an evaporator cleaner, but I don't know if it's still available and your availability.

But it is on fleabay

LINK

 

[LA Z]

Thanks. If I don't get satisfactory results with dishwashing liquid/brake fuid and power washing, I may see if anything like that can be found locally, but I somehow doubt it. Any idea what's in it?

Not sure if this will help, but here is what's in it.
I think I bought it at Grainger.

 

[CJF]

It would have been safer to assume I am referring to the evaporator coil. When I say 'externally' I mean on the external surfaces of the evaporator, as opposed to referring (in a grammatically incorrect form) to the exterior of the vehicle.

Condenser is brand new, but Toyota no longer make the evaporator for RHD models, so it needs cleaning out.

Thanks for the tip on the product, I will see where I get with dish washing liquid and then brake fluid for the stubborn stuff.

So do you mean with the evaporator removed from the vehicle? Or still installed and inside its housing? Or...?

 

[Eurasiaoverland]

So do you mean with the evaporator removed from the vehicle? Or still installed and inside its housing? Or...?

It has been removed from the vehicle.

 

[Eurasiaoverland]

Not sure if this will help, but here is what's in it.
I think I bought it at Grainger.


View attachment 3221217

That's really helpful, thanks! My guess is the glycol product is the alumminium-safe solvent to break down what makes things stick to the evaporator, with the ether to evaporate off leaving it as a dry residue which can be brushed or blown out. I'll try glycol brake fluid and see what that does. Brake fluid has become my preferred product to get sticky contaminants off plastic and aluminium.

Currently the coil has been soaking in soapy water overnight (Thanks Spike Strip), I have been gently scrubbing the fins with a toothbrush to release 30+ years of dust and dog hair. This came from Australia and the dust is deep red.

As it came from the wreckers:

Following soaking and a bit of scrubbing (more needed):

Notice how the bottom of this 12 cm deep tray is obscured by the dirt in the water!

Thanks for the input everyone, I'll report back with progress.

EIO

 

[LCnAZ]

That's really helpful, thanks! My guess is the glycol product is the alumminium-safe solvent to break down what makes things stick to the evaporator, with the ether to evaporate off leaving it as a dry residue which can be brushed or blown out. I'll try glycol brake fluid and see what that does. Brake fluid has become my preferred product to get sticky contaminants off plastic and aluminium.

Currently the coil has been soaking in soapy water overnight (Thanks Spike Strip), I have been gently scrubbing the fins with a toothbrush to release 30+ years of dust and dog hair. This came from Australia and the dust is deep red.

As it came from the wreckers:
View attachment 3221258

Following soaking and a bit of scrubbing (more needed):

View attachment 3221260

Notice how the bottom of this 12 cm deep tray is obscured by the dirt in the water!

Thanks for the input everyone, I'll report back with progress.

EIO

Holy crap! I think I would have tried a strong vacuum with a brush attachment initially while dry. It seems to me that agitation flow through is what is needed...in the direction that air normally travels through it. Perhaps change out your pan water frequently and just keep lifting and lowering, unfortunately for a long time. How about running it through the dishwasher? lol Anybody tried that?

 

[Eurasiaoverland]

Holy crap! I think I would have tried a strong vacuum with a brush attachment initially while dry. It seems to me that agitation flow through is what is needed...in the direction that air normally travels through it. Perhaps change out your pan water frequently and just keep lifting and lowering, unfortunately for a long time. How about running it through the dishwasher? lol Anybody tried that?

Because there are many laters of fins in the unit and probably 90% of the crud is on the most up-stream of the fins, I am of the opinion that it is better to backflush it, so to push the crud out the way it came, rather than push it further in.

Having soaked for 24 hours and made the water in the pan filthy, I took it out and pressure washed it (keeping the nozzle at least a metre away from it). A satisfying pool of red Australian dust formed on my driveway.

Yet still, the first row of fins is red-brown with dirt. Once it has dried I am going to generously paint the front with brake fluid (glycol), let it soak, get what I can off with a toothbrush, then give it another power wash and call the job done.

EO

 

[dogcruiser]

That's really helpful, thanks! My guess is the glycol product is the alumminium-safe solvent to break down what makes things stick to the evaporator, with the ether to evaporate off leaving it as a dry residue which can be brushed or blown out. I'll try glycol brake fluid and see what that does. Brake fluid has become my preferred product to get sticky contaminants off plastic and aluminium.

Currently the coil has been soaking in soapy water overnight (Thanks Spike Strip), I have been gently scrubbing the fins with a toothbrush to release 30+ years of dust and dog hair. This came from Australia and the dust is deep red.

As it came from the wreckers:
View attachment 3221258

Following soaking and a bit of scrubbing (more needed):

View attachment 3221260

Notice how the bottom of this 12 cm deep tray is obscured by the dirt in the water!

Thanks for the input everyone, I'll report back with progress.

EIO

Oh wow, it is your evap coil. And you weren’t joking about the filth stuck in it.

 

[ceylonfj40nut]

Do you have access to a sonicator? Warm soapy water and buzz.

Or place in pot and place on simmer with stronger soap.

 

[ToyotaMatt]

Do you have access to a sonicator? Warm soapy water and buzz.

Or place in pot and place on simmer with stronger soap.

were you the person that was adding a low pressure cut off switch recently ?

 

[ceylonfj40nut]

were you the person that was adding a low pressure cut off switch recently ?

No

 

[Eurasiaoverland]

Do you have access to a sonicator? Warm soapy water and buzz.

Or place in pot and place on simmer with stronger soap.

Both nice ideas, thanks. Sadly I don't have an ultrasonic cleaner, though they look like a very nice thing to have. Heat and stronger soap might be a good option if the brake fluid does nothing.

 

[LCnAZ]

Because there are many laters of fins in the unit and probably 90% of the crud is on the most up-stream of the fins, I am of the opinion that it is better to backflush it, so to push the crud out the way it came, rather than push it further in.

Perhaps the airflow direction through it is not what I thought. Perhaps it's so completely trashed through and through that it will not much matter in that respect.