At Least the Evaporator is Apparantly not Leaking - Page 3 - PeachParts Mercedes-Benz Forum

samiam4 · #31 07-23-2004, 12:10 AM

Good evening Larry,

Yea, I'm with you on a/c performance right now. I decided the 86' would get all new actuators just because of the age.

I haven't had any heater core problems(?). Just noticed a faint wetness on one of the orginal hoses.

Just a thought- I've run into several cars- GM, Ford and Mercedes which have behaved this way. All of those cars had dirty evaporator cores. For the W123, I was used a comercial "no-rinse" product. For the quick and dirty jobs .. I drilled an access hole and plugged.
I know they make the no-rinse with a flexible hose extension. I'll probably do it when I've got apart. I think the automotive stuff runs $10-15 a can. Talking with shop guys.. they only seem to acknowledge mild killing stuff. All the comercial HVAC guys are familiar with these products and use them.

Michael

#32 07-23-2004, 08:21 AM

I don't doubt that the evap could use cleaning, but I don't think that is my problem because the refrigeration portion performs so well. It performs beyond the performance specs in the manual.

If it were recirculating as it should I could make ice cubes.

I am glad you brought this up though. If I can get to the evaporator to clean it while I'm in there I will do so.

Have a great day,

samiam4 · #33 07-23-2004, 01:50 PM

I'm sure you will have access when you are in there...

It will make the air seem much fresher- even if you don't think you need it!
Reduced airflow is ussually the key element I see. Check the pressures and vacuum elements... then I investigate cleaning.

Michael

#34 07-23-2004, 04:50 PM

Well, as it turns out I have to drive to Kansas next week, so I am going to postpone this job once more. I hate to try to do it in one very hot weekend.

When I get back, I shouldn't have to travel again until Aug 23, so I should have enough time to tear it apart and no be so hard pressed to get it back together.

Have a great day,

#35 07-31-2004, 09:28 PM

I got the car positioned on the lift so that the front doors would open. I positioned a squirrel cage fan to blow through from one side to the other.

I raised it up far enough to disconnect the speedo cable and drain the coolant, then let it back down to a level where the bumper is slightly above waste high. This height really works well for getting under the dash and still it is easy to climb in and out of the car.

I got the instrument panel off and all has gone pretty well so far. The only bad thing that happened was that I broke the rocker switch carrier where it snaps into catches on either side of the upper most portion of the console. I might be able to JB Weld the piece back onto the carrier.

I have about four hours in the job so far, but part of that was hauling the fan and getting it in place, getting the car positioned just right on the lift and so forth.

It looks like I have a lot of work left to do. I estimate about 3 to 4 hours to get all the pods replaced and to replace the heater core. Then I expect it will be every bit of 4 hours after that to get the dash back on and fill the cooling system, etc.

I hate working under the dash and I'm not near through yet, but so far it's not as bad as I thought that it would be.

Have a great day,

psfred · #36 08-01-2004, 12:57 PM

Larry:

Having just finished the job myself (plus evaporator), here's some tips!

You do not have to pull the AC box to replace the servos, but it will be a PITA (less than pumping down a leak-free AC system, though!).

You will need an 8mm nut driver and 8mm ratchet, and a 10mm wrench, plus a 24mm to remove the headlight switch nut. Small and large phillips.

You must, alas, remove the console to replace the floor flap servo, but if you don't need that one, you can leave it in.

You need a flexible blade putty knife to get the trim strips off the speaker covers, preferably blunt so you don's scratch anything or cut yourself like I did.

Removing the trim on the A pillar is a huge pain, my clips didn't come (they are still in there) and the guys who replaced the windshield a couple years ago glued them to the glass, so I suspect the are ruined anyway. You have to persuade the clip of out of the A pillar from behind -- DO NOT USE A SCREWDRIVER unless you want to replace the windshield if you slip.....

All but one of the servos is held on by little twist lock feet and a locking tab. The center vent on on top has three posts and pushon clips -- get new clips, I shot two of them across the room since I had to break the pins off to get the sero off.

Otherwise, fairly easy, if very fiddlesome.

If the servo inside the box (diverter flap) is bad, you must remove the AC box on pre 1990 models. later models let you reach through the top.

For just servo replacement, you don't have to remove the cross member under the dash.

Going back in, I found it much easier to remove the center vent than to get the hoses connected with it in place -- one screw on the right side, two spring clips on the left. A small Torx screwdriver fits nicely into the hole on the spring clip so you can pull it inward to release the clip.

More notes available if you need them.

Peter

samiam4 · #37 08-01-2004, 07:23 PM

Hey larry,

I've got my box of vacuum actuators right here! Maybe I should drive up at leave the car with you for a week...

Much more industrious! But, hey I've got a new member of the family occupying my time since 7/17. Got to say- he's a cute.

Michael

samiam4 · #38 08-01-2004, 07:29 PM

Arrh?

"If the servo inside the box (diverter flap) is bad, you must remove the AC box on pre 1990 models. later models let you reach through the top."

Are you absolutely sure? I was going to go with the post 94 airbox assy, but was assured that I could replace the diverter servo without removing the box.

Michael

#39 08-01-2004, 07:33 PM

psfred,

I appreciate all the tips, but I already have the instrument panel off.

I am also replacing the heater core, so the top cover must come off. There are two phillips screws in the front of that cover that are near impossible to get at. I can't get a stubby, a short phillips, a regular phillips or an offset on either one of them. The metal that protrudes rearward from the base of the windshield is in the way bigtime. When I was in the military, we had a phillips screwdriver with a long flexible shaft like a speedometer cable. We used it to get in some tight places on a missile control system. If I can find such a tool, I can get to them. I am stalled until I get these screws out. Any ideas?

samiam4,

When I started reading your post my first reaction was that if you show up wanting me to do a podectomy I will meet you at the door with a shotgun.

Then when I read about the new addition to the family my heart softened some, I would leave out the shotgun and only politely tell you to go away.

This job is a real pain and there are many clips and stuff to break. The person that I WOULD meet at the door with a shotgun would be the engineer responsible for making this thing such a PITA to work under the dash.

Have a great day,

samiam4 · #40 08-01-2004, 07:56 PM

.... Sorry to hear the pain. I'll get to mine next week.

I'm just in a concern about having the right parts and all the right parts... eeek! This thing about having to pull the airbox on the 86' is worrysome to say the least. If I've got the dash out and have to pull the evaporator- I'm going to be replacing a few more a/c components.

Way too hot lately without good a/c.

Michael

psfred · #41 08-01-2004, 09:35 PM

Larry:

Check all your right angle rubber connectors, too -- all of mine at the switchover valve were bad (some had already been replaced). AC works great, but I broke that switch rack, too. What happened to a couple screws or a spring clip rather than prying away at the plastic?

It's much easier to replace the vacuum elements with the AC box out.... but I'd rather mess about with the box in.

Those two screws are rather difficult with the box out, too. I used a small phillips at an angle, but I expect you are up against the windshield, too, right?

If you are using a small, inexpensive "phillips", check the point. If it's pointed rather than flat on the end, grind a bit off and it will fit better. A stubbie is too short, a standard that actually fits is probably too long.

Michael:

Yup, you have to take the case apart, no way to get your hand in through the diverter flap. Changed later, exact date I'd have to look up.

Change the lamps in the headlight, ashtray, vents, and climate control while you have the whole thing apart, you have to take most of them out anyway!

I'm not quite done yet -- have to get new right angle connectors and new push rivets for the glove box (they nearly all stuck coming out and I ruined them) and I dropped one of the climate control mount screws and so have to fish it out from under the front seat to wrap up.

Also have to get the gunk out of the ash tray pivots so it doesn't groan when it's opened and find some screws to mount it with -- they were missing (someone has been in here before me!).

Peter

samiam4 · #42 08-01-2004, 09:56 PM

Psfred,

I though you were to pop the diverter flap out of it's place carefully. I think Easley had a write up.

Michael

psfred · #43 08-01-2004, 10:06 PM

you can if you want, but you will have to have smaller hands than mine to reach in, it's too small as I remember, and no, I'm not gonna take it back out to check!

Manual is pretty specific, prior to 1990 sometime, you take the box apart, after than date you just take the top cover off.

you can check the servo from the switchover valve easy enough.

Peter

brewtoo · #44 08-01-2004, 10:58 PM

Hey Larry,

Show us some pictures!

#45 08-02-2004, 11:53 AM

The servo is good, I checked them all before tearing it apart and only the fresh air and defroster leaked. I will replace them all while I'm there.

I need the two screws out so I can replace the heater core. According to factory service info and what I see taking out those two forward screws will indeed provide access to the servo AND the heater core.

I am going for a flexible phillips screwdriver at lunch and I found something called a "Skewdriver" in the ToolSource catalog. I am pretty determined to get these two screws out. I do NOT want to disturb the non leaking evaporator just to change the heater core. If I have to I will leave the heater core and that servo in place before I will TOUCH the evaporator.

As far as pictures, I think it's all too ugly to show pictures. I will see what I can do.

Thanks for the replies,