126 evaporator cleaned (and minty fresh )
 

After seeing this: http://www.peachparts.com/shopforum/tech-help/74964-evaporator-out-300td.html?highlight=evaporator , and always being in search of better air conditioning, I decided to see if I could clean my evaporator while it was still in the car, since evaporator replacement wasn't in my holiday plans. ;)

I've used aerosol foam evap cleaner on other vehicles; where you shoot it in the air box on the coils through a drilled hole or a screw hole and knew that this wouldn't cut it for what I saw in the picture.

I did the following:

1. Remove A/C fan thru the usual methods (good time to check brushes and lube motor with Singer sewing machine oil or ATF).

2. Stick my medium sized hand in the air plenum until I could feel the right side of the evap and get an idea of layout. Looked to be ~ 24 in (measured with flexible tape) from the plenum opening to the left (driver's) side of the air box.

3. Shop vac attached to a reducer and 1/4" hose with brush end (firmly attached) that is made for vacuuming computer stuff. Wormed in from blower fan opening and vacuumed as best I could (probably not overly effective, but I stuck with it).

4. Taped up a larger (1" diam.) test tube brush to a thin flexible bamboo nursery stake (~1 ft. long) and taped a vinyl hose (~1/4") along the stake so the end would squirt onto the brush. Then pushed the end of the vinyl hose on to a high pressure brass nozzle on a garden hose.

5. CHECKED TO BE SURE MY A/C CONDENSATE DRAINS WORKED PROPERLY.(or you'll be swimming in your car!)

6. Stuck my brush/hose/ bamboo handle assembly into the evap box through the blower fan opening and turned the hose on low. I used a spray foam disenfectant/cleaner also, and gently cleaned the evap in an up and down motion (following the fin direction), starting at the left and moving right , section by section, removing the brush assembly occasionally to clean the lint, dirt and hair off of it. I had to break off some of my bamboo "handle" as I moved right in order to finagle into some of the areas. Water flowing freely out the evap box drains and onto the pavement under the car.

7. After doing this gently (removing it often to clean the brush and squirt cleaner in) for about 20+ minutes, I bandaged up the cuts on the back of my hand and put it all back together. Have some rags ready for the inevitable water spills and don't drop anything into the air box (maybe a safety string?)

Risk of accelerating a pinhole corrosion of evaporator = unknown.

Don't know if it will truly help airco get cooler or more efficient, but I think it will help because I pulled out a LOT of CRUD. It was what you might imagine, viewing the picture in the referenced thread. With the electric sunshade, parallel flow condensor and some other A/C tweaks I've done, I'm getting ready for summer.;)
FWIW.;)

Just how dirty was the evap? Looking at the pic in the other thread, any cleaning would be a good thing. I recently replaced the evap in my Volvo 960 wagon and it had some dirt and leaves in one corner. The car has no filter. My V70 has a filter so shouldn't suffer from crud inhailation. I suppose the 300SE has not filter. Maybe I should vacuum out any crud.

From the amount of stuff I pulled off the brush, and some country reckoning of what went down the drain, I'd say my 1984 300SD was about 1/3-1/2 as dirty as the picture Dave Morrison showed.

evaporator coil cleaner?
 

i am thinking of doing this in my 1984 like jbaj007 did. through the blower motor opening, the evaporator feels linty and dirty to the touch and i think it is limiting air flow on this 22 year old part.

hvac supply sells a non-acid base evaporator coil cleaner Akti Kleen (Virginia KMP); it claims it is self rinsing, system condensate rinses dirt and detergent away, helps maintains max efficiency, fast acting, removes dirt, oil, grease, lint, smoke film and slime accumulations it is green in color and has a scent.
$12.75 gallon. apply with sprayer or hose after mixing.
what do you guys think?

my drain is not clogged and drains fine, my only fear is i might aggravate something on the evap coil/tube or fins...like a leak or rust spot.

How about this stuff?

http://www.autoacsystems.com/_store/storeopen_odor.html

Anyone try it?

Charles, I think I would use other things to clean first... it does not claim to be much cleaner and seems to leave some kind of film on the fins... which might be ok once the thing is really cleaned.

Not sure if this applies to all cars, but when I was low on refrigerant, and the A/C was on overdrive trying to cool the car with warm air, I noticed an elevator-like door that slowly rose up, blocking, or down, exposing, the evaporator through the center vents.

It would have been really easy to spray a solvent/cleaner in there through a standard aerosol can straw/hose, or any other that would fit through the vent opening.