Clean your evaporator !!

[Stevesnj]

So my A/C non cooling issue started last year, and after charging it twice it turns out the evaporator core was rotted. I purchased the truck in june 2011 and worked till the next summer then stopped getting cold. Charged it again and it lasted till this May. I charged it again and the charge lasted 2 weeks. I happen to work at a Votec high school with an HVAC shop and they charged and dye tested it and sniffed it and they couldn't find a leak. The teacher said the only place they cant test is the evaporator core. So this weekend I removed it, 30 min, and there wasn't a lot of junk in there, leaves bugs etc. But enough to rot the bottom of the core. Seems the acids from the decomposing junk in there rots the cheap metal of the core. thus a leak started. I got 245k miles out of this core, unless the PO changed it, but if you get a chance take the time to clean out the core. It's worth the effort.

 

[John E Davies]

Use a bottle of this cleaner every couple of years and that won't happen

BG Frigi-Clean®
Odors, bacteria, mold, spores, fungi, road grime, nicotine oils and debris accumulate in your car’s air conditioning evaporator. BG Frigi-Clean® restores heating/cooling efficiency and freshens interior air. It is a unique cleaning solution designed to quickly and effectively remove foul odors, bacteria, mold, spores, fungi, road grime, nicotine oils and debris that accumulate in your car’s air conditioning evaporator. BG Frigi-Clean® is injected directly into the evaporator case. It foams up to completely fill the evaporator core where it also blasts away bug parts, pet hair, nicotine residue and other garbage. BG Frigi-Clean® is biodegradable, non-toxic, non-corrosive.

http://www.hondapartsdirect.com/air-conditioning/bg-frigi-clean-a/c-evaporator-cleaner/bg709/

It relies on condensation on the cooling fins to flush away the cleaner and crud, so it is best to do the job on a hot humid day, a day you would normally expect to see water coming out the drain. Don't expect it to work well on a dry winter day. If you have never used it before, park outside and be amazed at the goo that it leaves on your driveway!

Once you have found a suitable place to drill a 1/4 inch hole and screw in the service port, it is an easy job. You just have to let the foaming cleaner work for at least ten minutes before running the AC on High to flush the evaporator and cavity...

Any vehicle without a fresh air filter needs to have the evaporator cleaned routinely. I have three cans of the Frigi Clean sitting on a garage shelf. It's good stuff. $25 per can is a pretty good price - it is very expensive over the counter.

John Davies
Spokane WA USA

 

[nemoblackdog]

Be warned, once you get to a certain point, even the Frigi-Clean won't touch the accumulated grime. This is what an evap core can look like after two (expensive!) Frigi-clean treatments. (And several Frigi-fresh treatments, too).

Very stinky - especially if it's wet & humid out there. I also had a small leak caused by this rot. Only cure was a new core. To have fresh smelling air once again was more than worth the cost and effort!

 

[allan man]

Is it possible to clean the evaporator core without disconnecting the Freon lines? Maybe just take apart the housing underneath the glove box to avoid evacuating the whole system?

 

[Stevesnj]

If you can get to the screws on the bottom of the core casing then yes. But im sure it would be a chore.

 

[allan man]

How many screws are there in the bottom? Does the housing for the core separate into 2 halves?

 

[Stevesnj]

Yep it does separate into 2 halves. There are clips and screws and foam insulation that will get torn during separation.

 

[PHIL O]

just did mine. had to remove the whole box that houses the evaporator and blower. to clean the evaporator, i dissolved half a cup of flaked lye into a bucket of water fully submerging the evaporator. be careful not to get water into the evaporator pipe interior. wait for a few minutes and the lye solution will get to work dissolving all organic dirt in between the fins. after about 5 to 10 minutes soaking, spray with clean water. voila. cleaner than any frigi clean chemical can do. and very cheap

 

[1FZj80]

Remove the fan blower and the big resistor thingy and with a small shop vac you will be able to do a pretty good job cleaning the evaporator. The opening into the evap box is small, but you will be able to remove everything from the lower half of the evaporator which is where it gets clogged. You will also be surprised how much clag gets stuck in the blower and on the fan blades.

 

[Timpanogos Slim]

just did mine. had to remove the whole box that houses the evaporator and blower. to clean the evaporator, i dissolved half a cup of flaked lye into a bucket of water fully submerging the evaporator. be careful not to get water into the evaporator pipe interior. wait for a few minutes and the lye solution will get to work dissolving all organic dirt in between the fins. after about 5 to 10 minutes soaking, spray with clean water. voila. cleaner than any frigi clean chemical can do. and very cheap

Lye will eat the aluminum, no?

 

[Stevesnj]

In my other car i just used Simple green and a nice flow of water not a nozzle. Flushed the dirt right out. Cleaned it out just in time.

 

[PHIL O]

Lye will eat the aluminum, no?

if you leave it soaked for way too long and with high concentration. but at controlled amount and time, no harm. aircon shops use lye to clean evaporators

 

[luckysob]

My ac was working but had the smell of a fish tank (florida its whole life).

I took off the evap housing cover behind the antenna relay and used a variety of pipe cleaning brushes to clean the side that faces the fan alone with cleaned it w Simple Green * Fungicide * then followed up with vinegar. - i assumed the other side was clean ( and it was after checking w a bore scope).

Has anyone figured out a way to clean out the area in the lower part of the housing that connects to drip hose?

 

[COYS]

Is this a factory replacement part? If so what’s the parts # breakdown to do the job? Thank you.

 

[jpoole]

I had some success accessing and cleaning the evaporator through the opening left when the blower motor is removed. Not having carpet currently means that the overspray just runs out the floor drain plug.

After pulling the blower I was able to get a shop vac into the box holding the evaporator core for the big chunks. What was more helpful was spraying evaporator cleaner, letting it sit the prescribed length of time and then rinsing with the water hose thoroughly. In between those spray outs I scrape the gunk out with my hands and a plastic stick (trim pry bar) that fit well and didn't damage the core. I used a borescope to monitor my progress and I think I have ended up with a fairly clean box. I plan to repeat the process annually but for it to be a lot easier in future years.

Completely removing the evaporator is definitely going to lead to a better clean but the above does pretty well and is easy enough to do every year.