Everyone rebuilding their A/C system should clean out their HVAC assembly box!
 

When I went through my A/C about 5-6 years ago, I knew I should of did this to my then 25 year old car. Now I'm disgusted to know that I, as well as my family and friends, have been breathing in this crap all these years.

Outside air intake shot immediately after I pulled the whole HVAC unit.
http://www.peachparts.com/shopforum/...1&d=1369085087

Upper outside air plenum. Filthy interior shot with the cover removed.
http://www.peachparts.com/shopforum/...1&d=1369085095

Evaporator - Filled with so much crap that part of the evap is in poor material condition from corrosion.
http://www.peachparts.com/shopforum/...1&d=1369085104

Heater core also took in a lot of dirt.
http://www.peachparts.com/shopforum/...1&d=1369085113


:eek:


I now need to figure out how to implement a cabin filter to keep this box clean.

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Man, that is some nasty stuff there. It appears old car = lots of gunk in the air system. When I see things like this it makes me wonder how the air handling systems on commercial passenger aircraft look like......we can only imagine.....

Bummer no change or straws :D

I'll do this when my heater core fails or I find a mint condition w123 that I can afford....till then my climate control involves rolling the windows down...technically not much better...

I did find a dime down in the Heat Exchanger slot.:)


http://www.peachparts.com/shopforum/...1&d=1369088305



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Nasty! What was the reason to take it to bits this time? I'm sure mine is as dirty. I'm considering doing this solely for air conditioning performance and smell improvements.

Air flow performance was an issue every year in this 105 plus degree heat we have here. Vent temperatures were great though. I figured I'd redo everything including a Sanden compressor upgrade, use of a bigger parallel flow condenser then previously used and finally sound proof the fire wall.

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I could pay you a dime to do mine!!!

When I did my A/C rebuild last year, I was pretty sure that everything was fairly clean. However, I did not pull apart the HVAC system. Maybe I can run vacuum hose in there if I find a good dash and do the swap.

I have a piece of wood wedged in my blower compartment to keep the fresh air flap 100% closed. I did that to maximize A/C efficiency but I can see the other benefits. Keep us posted on what kind of filter setup you design.

Almost .....
 

DeliveryValve ----

Your evaporator didn't look as bad as mine and you got paid more :( I only found a penny down in the defrost area. I like the idea of a cabin vent. Maybe something over the bottom of the blower???



Just for comparisons sake, here's what the 1984 Light Ivory evaporator looked like:

http://i485.photobucket.com/albums/r...x/DSCF0643.jpg
http://i485.photobucket.com/albums/r...x/DSCF0644.jpg
http://i485.photobucket.com/albums/r...x/DSCF0645.jpg
http://i485.photobucket.com/albums/r...x/DSCF0647.jpg

I once removed a 98 camry evaporator ( for a college student freind) - that car also does not use a filter, and it was similar to these pictures, Toyota sold a product in a can that was really powerful it was expanding foam and it pushed itself through the evaporator, heater core etc literally melting the dirt. btw I had to do 4 passes back and forth to make it brand new again.

But just saying, I think the product being sold on pelican with a long straw is similar.

oddball bit

toyota provided a slot for a filter in that car - yet they forgot to install it in the factory.

maybe you could duct the climate control air inlet to the engine air filter, and use the same air filter for both applications?

throwing out ideas, however ridiculous

I think you'd want to throw that idea in the brown file. I wouldn't want hot or cold blowby coming through my vents!

well, that would certainly be bad. :D

I was thinking more along the lines of an aftermarket cone airfilter with a T right after the cone, and ducting that runs to the engine from there.

however, for that amount of work, he might as well just adapt a cabin air filter from some other application that fits nicely.

I've been thinking of doing this with my DD. I can only imagine the crap stuck in there.

Now there's some comforting pictures - thanks for posting them folks!

I agree, is there a thread here where deliveryvalve has done a step by step on this process?

basically, every car needs a cabin air filter.

Another pic to make you feel happy stretch. :D Not MB, but same problem of no air filter-

http://i1217.photobucket.com/albums/...etta/015-1.jpg

I've been working on A/C systems for 30+ years... them's pristine... you ought to see what a coil looks like in a rental house that originally had a floor furnace, converted to a 30x36 return air grille... that's SUPPOSED to have a filter changed each month for the 15 or so years the tennant has lived there with dogs and cats and kids...
imagine the blower cage on the car is 16" across, the coil is 30" square, and BOTH are completely filled with hair, and leaves, and toys, and dead animals, and clothes, and shoes, and food, and, and and and and...
I'll clean car systems ANYDAY!!!
renters SUCK!

hotel wall units are only MARGINALLY better...

Oh great I'm never going out now - even when the children have grown up...

I can totally relate to that. the place I am in I believe did not have the blower serviced in about a decade or so, when I removed the squirrel cage, firstly it was not working as a fan as the little blades were now cylinders. I counted 20 roach mummies and tons of other stuff like lint, hair etc. I cleaned the coil in situ the best I could with drip pans and otc products.

I will almost never want to do that job ever again. YUCK.

on the plus side... I usually find hundreds of marbles when I clean out one of those systems...

You can get that foam cleaner at Home Depot or anywhere that refrigeration supplies are sold. It works great, but does not substitute for disassembly and cleaning.

I used the foam cleaner on the evaporator and heater core. It would have had very limited cleansing power without disassembly. In addition, these type of products don't require rinsing on coils that produce condensation.

X2, Renters suck.:mad: been there.

I rent now and take care of the place as if I owned it, but when I rented out a place I once owned ( I know getting a little :offtopic:Here) the place had Electric Heaters in ea room. I had installed a Fireplace Insert. wasn`t getting my rent money so went up there to see what`s up. I see a tin pipe sticking out one of the rear Bedroom windows. they had dragged the Insert to the Bedroom, set it on some bricks and had the fire going in the insert. :eek:


I have a 240D Air/Heat box I took apart, and it`s AC Condenser was pretty full of debris too. I really don`t see how spraying is some Condenser Cleaner will make all that stuff disappear.

Charlie

This foam was not the home depot type thing, the can said made in japan something and it came out like heavy shaving foam under massive velocity, it would react (start to grow) when it touched dirt and the foam would turn gray and finally into black ink colored stuff after about 10 minutes.

Smelled heavily like lemony butane.

msybe vstech knows of something similar coz that toyota dealer says they dont have it anymore and its no longer supplied as all newer models have cabin filters.

I had to change the expansion valve on that one so when I had the dash apart I cleaned out everything, all ducts were major dirt caves too.

I don't know, that evap of mine seemed to be 85% clogged. The dirt and resulting water from the evap caused it to deteriorate.

New unit is coming soon. BTW - the w123 evaporators according to my local parts guy will be discontinued this year.


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I'm planning to use the limited space in the cowling to add in a cabin filter for the outside air intake. I am also going to put a cabin filter for the inside air intake.

So far this is for the outside air intake.

This is the cowling opened up with the windshield wiper assembly removed. Not shown, but part of the wiper motor sits on top of the HVAC intake. It would of been easier to add in a filter if this was not the case.
http://www.peachparts.com/shopforum/...1&d=1369188471


Another shot.
http://www.peachparts.com/shopforum/...1&d=1369188480


Hopefully the filters I choose will be sufficient because they are on the small side. They are for the 1999 - 2002 Chevrolet Silverado. They come in a pack of two and Measures 5 1/4" x 9 1/8". Originally suppose to be installed side by side in the Silverado HVAC box. But I will use one for the outside air side and one for the inside air side.
http://www.peachparts.com/shopforum/...1&d=1369188487


I chose this filter because of the space limitations in the cowling. This is where I plan to place the filter. I am going to make some ducting from fiberglass to snake around the windshield wiper motor and connecting rods.

http://www.peachparts.com/shopforum/...1&d=1369188494



Any thoughts?



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How long did it take to get the air box out? I have heard people say many day's work, but maybe there is a trick they don't know. I have looked at several 300D's partially stripped in the junkyard, but it looks like a lot of work even after removing much of the console. Specifically, I need to change the heater core in one of my cars, plus a cleaning inside.

From someone who spends 100+ nights a year in hotels now I am totally disgusted.

Almost every Hampton Inn in the country has that stupid through the wall buzz box system.

I removed a manual airbox in the junkyard in less than 3 hours. Cleaning takes longer because you have to decide what to do on all the flaps. Do you re-install insulation or not. You might want to look over in my 1984 Light Ivory 300D thread. Re-installation of the airbox is long; still working on it.

I would say it would take that long as daw_two stated, I've been taking my good ole time on this.



dmorrison did a write up already.

PeachPartsWiki: Replacing the A/C Evaporator


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I originally had the cheeky idea to just cut a hole in the HVAC box to access the "fresh" air side of the evaporator for cleaning... too bad that's the side that's against the firewall :(

-J

So. If the engine weren't in the way, permament installation of a firewall door with further access to the evaporator would have been a good option. Tongue in cheek.

Of course, my motivating was not to clean the evaporator, but to get rid of all of the vacuum pods and the ACC. Manual airbox all the way!!!!

Yikes! From scrolling through the wiki about Dave's removal, it might be easier to pull the engine and cut a hole for access. He definitely did the right thing by taking a lot of pictures. I've done heater and evaporator changes on cars in the past but none of them appeared as painstaking as the W123. I wonder if the W126 series is any easier.

I used Dave Morrison's thread to guide me. In addition, I had removed a manual airbox from a 240D in the junkyard. Here's the pics I took in taking the manual airbox apart:
How To Disassemble A W123 Manual Airbox Photos by daw_two | Photobucket

Re-assembly is the reverse, right? Yeah, right!

Here's what the 240D donor car for the manual airbox looked like when I left it.
http://i485.photobucket.com/albums/r...x/DSCF0418.jpg

The W126 evaporator can be accessed with the blower removed. It's tight but I have done it many times. Water hose and a wet vac does wonders after brushing and vacuuming the fuzz off.

On a side note, did that car have that awful sound insulation on the firewall in which there is a outer layer of plastic, then foam glued on the sheet metal?

Mine has that crap, I ripped it all out!
Damn you Mercedes Engineers! You should of known you would build a 30 year plus service life car and that all the foam underneath the plastic shielding is rotting away and contributing to my increasing hearing loss! More pain in the arse!
$@##!! @%%&*! >$"^^!!!

http://www.peachparts.com/shopforum/...1&d=1369799168

http://www.peachparts.com/shopforum/...1&d=1369799177


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That's good to know. Will have to do that on my next w126.


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87 Champagne with an almost virgin engine and transmission would make the trip to CA. :D

I did do that (I made a long nozzle using a piece of copper tubing), not sure I got it all clean though :(

-J

um... that's not foam... it's asphalt.

yup... hotels swap out the wall units when they no longer cool/heat... and the "maintenance man" crew gets to "repair" or "renew" them...
I get called in when that no longer works... and I get to see the NASTYNESS that guests toss in there, and what gets past the filter...

yep, if its peeling off then refinish with heavy butyl sheet and ensolite foam.

I dont' think that is foam. I had one little piece tear off on the passenger side of the transmission tunnel --- I need to update my car thread with lots of pics. I need to put something over it, because it is still gooey before re-installing the carpet panels. That's probably months away...anyhow, so I'm not too concerned right now.

There are a lot of sound suppressing products available for automotive use. this is the first I had heard of Ensolite Foam, so had to go search.

Ensolite IUO --- 1 yard (14 sq ft), Glue On version ( I recommend the PS version for most installs as far easier to work) - RAAMaudio Inc.

Mat and Foam Products - RAAMaudio Inc.

Ensolite is the blue pads that Back Packers use and have rolled up in their back packs. Read this on a Camping Forum in my search.

Here is another source.

Foammart

Zilfigar, the Butyl sheet, is this like the stick on tar pad that Lowes and Home Depot sell in a roll? It has been mentioned in other Threads.


Almost every car in PNP that I have removed the front carpet, Dash and AC/Heater box, the acoustical tar pad stuff MB used 30 yrs ago is old hard and crumbles with slight finger pressure. It lost is original purpose long ago.

Charlie

EXCELLENT IDEA! Especially true since few people clean their cars yearly with ammonia to kill germs, or de-ionize them.

Guests losing their marbles over the crappy A/C?

From another thread, you said you used an Ackits PF 16 x 24 condenser and had Freeze 12 at the time. Is this the condenser? 12-0508B - Parallel Flow Condenser (16 X 24)

Did you have a post on the PF condenser install?

You'd changed your AC system quite a bit since 2013. I'd be interested in a description of the changes made and performance differences as a result of each change.

Actually my first Parallel flow condenser was 14x22.5 inches from AC Kits.
12-0437C - PF Condenser (14 X 22.5)

At that particular moment, sometime in 2007, AC kits didn't offer any other size that would work in a w123 when I needed one.

I posted the entire AC condenser and rebuilt R4 compressor install on the old schumanautomotive forum website. That was before that site went all paranoid and made everything private few years after 2007.

At the time, I thought the cooling was adequate with Freeze 12. But ultimately I swapped it out with R12 because I couldn't stand the drag the higher pressure Freeze 12 was putting on the R4 Compressor. As soon as I made the change, I remember the cooling went from low 40's/high 30's F with Freeze 12 down to low 30's with the R12. It froze me out sometimes with temps hovering at 32° out of the vents.
But when the car sat awhile in the 100° plus sun, I could feel I had a circulation issue, which brought me to the main topic in this thread. This endeavor was spearheaded by the untimely death from a catastrophic internal destruction of the rebuilt R4 that was installed 5 years earlier.




1) I made the jump to clean out the evaporator, which in the end greatly improved the air flow.

2) As I mentioned earlier, I had a compressor failure which blew up internally. Not a pretty sight, basically sending shrapnel through the lines. I was forced replace the majority of the lines and replacing the condenser as well from the shrapnel contamination.
I would end up buying a cheap eBay 16x22 inch condenser. Slightly bigger than the 14x22.5 AC kits condenser I had. I would also end up installing a later 2nd gen w126 electric fan to improve the air flow.
http://www.peachparts.com/shopforum/...8-09.34.17.jpg
Here is the thread: http://www.peachparts.com/shopforum/diesel-discussion/377850-86-91-w126-aux-fan-into-w123-300d.html#post3598398
As of right now, I would say the eBay condenser and 2nd gen w126 fan has done it’s job and cooled very well. I can’t really say if performance has improved upon what I had before, because it is all one system working together. But would guess it has.

3) One of my main concerns was the evaporator getting clogged up with dirt again. So I made a modification to the firewall and installed a fresh air cabin filter.
http://i252.photobucket.com/albums/h...psozbj4k6x.jpg
http://i252.photobucket.com/albums/h...psawh804yk.jpg
Here is the thread: http://www.peachparts.com/shopforum/diesel-discussion/357274-w123-outside-air-cabin-filter-addition.html#post3357291
I have to say this mod has been working out really well. I am using a basic 2005-2014 Mustang cabin filter. I found the charcoal activated filter types restrict the air flow a bit.

4) The other modification I did to the system had to do with the recirculation flaps. I live in an area with some dairy farms. If you know what I am talking about, it can get stinky. Sometimes, my system would draw in fresh air when I want them closed near those farms. I made an override switch. Which also helps with cooling down the cabin quicker occasionally.
http://www.peachparts.com/shopforum/...atingmod11.jpg
Here is the thread: http://www.peachparts.com/shopforum/diesel-discussion/366902-w123-hvac-recirculation-modification.html


5) Since I had a catastrophic compressor failure, I opted to go with a 7 cylinder Sanden 7h15 compressor using R12 refrigerant and Rollguys First Gen bracket kit.
Here it is mocked up on my spare motor.
http://www.peachparts.com/shopforum/..._rearhead1.jpg
I do feel the Sanden is a smoother operating compressor vs the R4. But performance wise, engine drag maybe the same and I am getting the same 32° F vent temps as before. So I feel I haven’t really upgraded in that aspect.

Issues… I do have issues with belt stretch and is trying to find a sweet spot on the Contitech belt size. I also was kind of stubborn and decided to try to make the hoses somewhat factory looking using the original A/C hose manifold to the connect to the compressor. As I type this, the manifold has cracked a second time at the braze repair from the first crack that it suffered previously. I have now lost my second 2.9 lbs charge of R12 to the atmosphere. I will have to determine if the crack was due to a faulty braze repair or was due to the use of a poorly modified R4 manifold.

I hope I answered the question you were asking.

Just to let you know, I have a stack of R4 manifolds. They are free for the taking, or you pay for the shipping and you can have as many as you need. If I were using the stock manifold, I would weld on a male fitting like I do for the pipe on top of the engine. That way the rubber hose portion can be disconnected if replacement is needed. Of course I would replace the hose anyway, and crimp on the proper fitting to screw on the manifold. I have everything to do so, it is just that the systems I do, I run a new hose above the engine, and not below.

Another thought, your manifold cracking could be because of the lack of brackets holding the manifold to the engine and/or compressor. Vibration is a major contributor to all the component failures of this system, so I can't imagine the stock manifold lasting without being tightly bolted to something. That is also the reason I use steel fittings on everything. There may be one exception, it is an inline charge port fitting for r12 that never sees vibration (I can't find them in steel).

How much room between your w126 aux fan and your parallel flow condenser do you have? I just swapped to a parallel flow but my stock fan shroud is about an inch from the condenser. I am thinking about switching to the oversized fan next time one shows up at the junkyard