Was thinking today why my wifes A/C doesn't seem to blow very hard or cool like it used to. I was thinking about cleaning the evaporator. Has anyone done this? Did it help. I've already checked the freon. It was a little low, but still well within range. I topped it off anyway & there was no change. It also seems to be affected by weather. It will freeze you out when it's below 80 degrees outside, but anything over that you may as well roll down the windows, because the ac just won't keep up.

For those of you that have done it, what all do I have to dissasemble to get to it?

Thanks
C

I cleaned it on my car while I had the blower motor out, it was surprisingly dirty. I used compressed air and a toothbrush and finished up with a good dousing of scented Lysol. It looks better, and probably transfers heat (ok, cold) better as well. There are special foaming evaporator cleaners that should do a better job, I plan to buy some and use that next time.

My car is a 124 so unfortunately I can't provide tips on how to access the 123 evap...

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Dave
Boise, ID
Check out my website photos, documents, and movies!

I think I've got a similar issue, so I'll be watching this thread carefully...

I got lucky with the truck; I pulled the a/c system apart (going to convert to R-134a) and everything looked clean. I'll bet the same won't be true of the 123! I'm hoping that discharging the a/c system won't be needed...

DMorrison did.... and posted pictures I think... pretty clogged... but big job the way he did it...
I am still trying to figure out how to use spray/vacuum to do mine ...

Noooooo...! Don't convert to R-134a!! If you insist on ditching R-12, use ANY refrigerant that will work with your original mineral oil (Duracool, Autofrost, etc). The PAG/POE oils required for R-134a are terribly hygroscopic (absorb water which DOES NOT boil out in vacuum like it will from mineral oil), and require a TOTAL flush of the old mineral oil first - that means pulling the compressor & draining it, flushing with the new oil, as well as solvent flush of the condenser, evap, and lines. Bad bad bad. When you're all done you have less efficiency and tremendously higher head pressures, which are a strain for the compressor, and sap more power from the crank as well. Conversions from R-12 rarely last more than 2-4 years before getting the "Black Death" syndrome.

(can you tell I don't like R-134a conversions? factory 134 setups are less of a problem - it's just the conversions that are bad!)

SIgh!...........

LOL

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Jim

Tim knows better than to change from 12 to 134... I think he was just trying to get a reaction from some old guys...

HVAC guys have an acid wash for the coils, I think.

HVAC guys have washes for outside coils... ( stronger ) and inside coils.... we should only use the inside for our evaporators....I will look at my gallon concentrate bottle and see if a name is still visible...

The condenser wash is an acid that's fairly potent, I think. The evap wash is usually a milder foaming stuff to lift dirt away. Or at least that's what I hear on the playground.

I've done it. Have to admit it didn't make any revolutionary difference as far as I can tell. Here's my previous post on what I did. FWIW.




After seeing this: http://www.peachparts.com/shopforum/showthread.php?threadid=74964&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

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The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)

"The condenser wash is an acid that's fairly potent"
Yes, plenty of warnings about being sure to rinse well.... or you just eat the fins off your condensor...

Jbaj007, You did my research for me... thanks.... that is what I am going to try....

But Greg,

It is all those pesky little fins that trap the crud and reduce the effectiveness of the condenser. Wouldn't it be so much better to not have that worry :p :p :p

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Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

The bottom of my evaporator box is forming condensation on the outside, inside the passenger compartment, over the passenger's feet. Is this box supposed to be insulated? It was much worse before I cleaned the drain, water was backing up in the box.

I am trying to plan an expedition under the dash, I would like to do this only once and do all of the underdash work in one project.

Note that is regularly 90/90 here this time of year. 90 temp, 90% humidity.

Also my car is a Euro car and doesn't have the ACC.

1982 300D Euro, manual trans, aftermarket cruise, cloth seats, manual sunroof, aftermarket front electric windows,