Best way to clean out the A/C evaporator and heater core?
 

Hi guys,

I've been searching on this topic, but wanted to get some 'live' advice.

My A/C and heater has a nasty musty smell when in-use. I suspect that the fins on the a/c evaporator and/or the heater cores are probably coated with build-up over the years, just like my other cars.

With the other cars, I have a way to open up the "input" side of the evaporator/heater and gently clean it off, usually with a garden pressure sprayer that has a very dilute mixture of Simple Green and water. I usually finish off with clear water until everything is clear. Works wonders.

What are the options WITHOUT tearing apart the dash and removing the evaporator. I've read the threads on that, and it is way more effort than worth it for just cleaning things.

I have read that people remove the blower assembly and then go in with a sprayer that way. Is that the only method? Best method?

Thoughts?

Thanks,

Packman

I can't speak for the W123 but on my W126, I removed the knee bolsters and had access to the evaporator so I could stick a pressure washer wand in there. I used the pressure washer at a manual car wash. First, I soaked the evap in coil cleaner.

I have used the lubegard evaporator cleaner on a chevy impala and 2 toyota camrys with success. The stuff draining out the evaporator was like ink

Hmm. I believe I saw that at the NAPA store. I seems to consist of an aerosol can of foam cleaner where you push it up through the evaporator drain/vent hole of the W123 (just above the tranny) and you just spray it around. It supposedly goes out as a foam and quickly breaks up into a liquid, which then comes back out of the drain hole.

It sounds like a reasonable first approach... but was hoping for something better...

Packman

Be careful shooting anything up the drain tube. MB used some very soft and brittle foam material that has usually disintegrated by now. You probably don't want a center console full of evap cleaner... To go that route, I would remove the side panel by the radio and shoot the foam in the tube that the drain hose connects to.

Access through the blower assembly is the only reasonable way to access the evap and heater core.

Coil cleaner or simple green would do well, coupled with the garden hose.

people swear by the toyota kit. if you have a toyota dealer nearby they should have it. its a two part kit, a foam cleaner/spray and then a spray mold reducer/eliminator. i'm sure there are equivalent products sold elsewhere.

A suggestion
 

Scrubbing bubbles for evaporator core cleaning.
http://www.scrubbingbubbles.com/Pages/default.aspx?sid=SEM_G_328.kw9364

Be sure to remove the carpets.

.

How on earth would you get that stuff up into evaporator core? I'm confused.

Thanks,

Packman.

Tear it all apart, it will give you the chance to replace any bad pods and all the foam that lines the flaps in the heater box.....this way you will have it working as it was attended....I am currently doing this to my euro...

Answer
 

I plug the drains and flood the climate control box with Scrubbing Bubbles® | SC Johnson
A vacuum pump is handy for moving the air blend doors, to assure total flooding.

Remove the plugs, allow to drool / drip for an hour, plug the drains, flood the box with water, drain, repeat as needed.


.

OK! This is exactly the kind of thing I was hoping for, but I'm still a bit unclear on the exact process, e.g.

1) Where are the plugs?
2) How do you flood the climate control box? i.e. where and how do you spray the scrubbing bubbles?
3) How do you use the vacuum tool to manipulate the blend doors?
4) How do you flood the climate control box with water?

Sorry to be such a noob... is there a pictorial?

Thanks,

Packman

i cleaned my evap in my w123 and my dad's old w123 with foaming coil clean from home depot. i dropped the blower and was able to completely clean it. i used my garden hose sprayer on different patterns to get all the crap out and kept my shop vac running to prevent the water from over flowing if the condensation drain were to clog. did the same on my w126. i would not keep the garden hose spraying for long periods as the water can't drain as quickly. also make sure your condensation drain isn't rotten as you will flood your car. if you stick a crevice attachment on your shop vac, you can get all the leaves, ect from the back corner but be very careful because you can easily damage the fins. as for the heater core, i wouldn't worry because the evaporator has probably filtered everything :) i stuck my phone in there to take pics and see if i missed any spots too! these pics were from the w126...

Thank you, this is quite helpful. I'll give it a try.

Thanks much,

Packman

Glad I could help! :)

found a pic from about a month ago of my w123's evap. i cleaned it over a year ago and it's staying clean. the air volume is VERY good with all vents open. before i cleaned it, i always closed the passenger vents in the summer because it was a pathetic amount of air flow. the coil clean has a good smell too :) not a chemical smell, but a new window air conditioner smell :D

Thanks so much, that gives me more encouragement. Just need for it to warm up a bit and I'll give it a go!

Thanks,

Packman

No kidding! Tired of this weather... you'll be blowing your sun visors back when summer comes around:cool:

Evaporator 1984 W123
 

When you pull the blower motor assembly and look at the evaporator is this the side that the air flows through/input. Thanks for any info

Yes

Thanks for the info, my problem is my center vent temp is about 37 degrees on low blower setting and about 58 degrees on high blower setting 94 degree ambient/80% humid. I have replaced the R4 with a sanden compressor and running R12,I suspect it is a dirty evaporator also air velosity out of vents is good but not great.

I noticed from this picture and the 2 others you posted earlier,
that the shots were taken from the same opening or access.
Was this opening big enough to fit a hand into it with a toothbrush
and a foam spray cleaner (no-rinse) to clean the fins?

Any tips you can share in taking down the blower motor?

I have a 300D 1984 USA model to work on and I've been gathering
pointers from Brian Carlton from another forum of a similar subject.

I also want to replace the motor brushes if I can find a good source.
Any tips on this too?

I'll look forward to your answers.

Thanks.

i was able to reach my hand inside with a toothbrush without issue. i tried to hold a can and put it through the opening but i couldn't. so i had to get the evaporator cleaner that has the hose attached to the can. in that case it was easy to reach up inside with the nozzle while pushing the spray button with my other hand. for rinsing i used a small pressure sprayer with a long hose.

there is nothing to taking down the motor. unclip the electrical connector, then there are just a handful of very obvious screws that attach the blower to the housing.

I am in the process now of refurbishing the whole climate control assembly for my car. After taking two of them apart, I can only recommend complete disassembly. Both have been completely full off dirt, dust, and garbage, not to mention that every bit of old foam is rotten.