I have a zillion questions to ask regarding pulling the dash, but I will wait until I know for sure that I will have to pull it.

If I do pull it, will it be the 15 hour job to get to the pods? If so, I will have to decide whether or not to just do the evap while I'm there. Since the system is not leaking I really don't want to even touch a refrigerant containing component.

Wish me luck,

Larry, this may be of some help in diagnosing those pods.

The post came from this thread:
http://www.peachparts.com/shopforum/showthread.php?threadid=42865




Good Luck!

__________________
-Paul-
'01 E430, Sport 72,000 mi
'98 C280, 126,500 mi

Well folks, some slow violin music is definitely in order. Line numbers 1 and 2 from the 7 port manifold won't hold vacuum. It takes about 5 seconds to leak off about 3.5 in. Hg. Also line 7 leaks. It seems like I remember the defroster not working earlier in the year, so that is now explained.

In another thread I was reading about someone having put in 3 different evaporators. My system seems to be holding refrigerant well, so I don't think I will do the evaporator. I hope this decision does not turn out to be the kiss of death for the evaporator.

I have all the service information printed out from the CD. The only thing about the operation other than just the time it will take away from other things, is pulling the airbag. jcyuhn, did that bother you in any way? The instructions for "disarming" the airbag seem straight forward, but it still concerns me.

We have been fortunate so far with the Texas heat. It's about 85 today, but the triple digits may not be more than a few days away.

I have to give this some thought since I don't have to drive this car every day. It is merely a backup. My wifes 4Runner wouldn't start last week while I was out of town so she drove this car to work until I could get home. BTW I simply had to put a fuel filter in her Toyota. The a/c was just like it is now and she didn't complain about it. We're talking about a woman that absolutely cannot live without air conditioning.

It is cooling, but not real well. I expect that when the triple digits hit, it just won't cut it, especially for her.

There is always at least a LITTLE good news in everything. If I take it apart, I don't have to rush to get it back together. Also if I go down to these actuators, I will have a lot of experience and hopefully confidence behind me if I ever have to do the evaporator.

Thoughts and comments are appreciated.

BTW, jcyuhn. If I would have taken your bet maybe all would have to do now is fork over some money instead of tackling this beast.

Have a great day,

I just had a thought. The way these are connected together, if one leaks, then in effect, they both leak since they are connected together before being connected at the manifold.

Is the one behind the glovebox replacable without pulling the dash? If so and IF I were VERY LUCKY, that might be the only one that is leaking and replacing it would make it operational again. Keeping me from having to do this job in the heat. It's something I would much rather do in October than July or August in Texas.

Thanks for your responses,

Larry,

Have you considered as to whether or not the repair is essential? You are probably like me and cannot stand the thought of something not working as it should. In a situation like this though, I would be asking myself if I could live with the problem (if no damage will occur) until there was a greater need to pull the dash apart (eg. evaporator failure). If it simply means that the air-con will not be quite as cold as it should, then I think I could live with it for a while.

I realise that your 124s got the pushbutton full auto climate control whereas ours got what I refer to as the "manual" climate control with dual temperature thumbwheels and rotary controls for air direction and air volume/fan speed. I therefore don't know how much is common between the two systems. I have mentioned here previously how we don't seem to get as many problems with ours with the lack of the pushbutton unit and associated electronics and our 124 evaporators don't seem to have the same reputation as yours. One obvious difference is that ours have separate left and right heater cores and where you have a mono-valve we have a dual version (a duo-valve?).

I'm fairly sure with ours, air volume and direction are controlled directly by the person moving the controls, so we presumably do not have the vacuum actuators/pods associated with these functions. We do still have a recirculation pushbutton and therefore at least one vacuum pod (maybe the same two as yours) for this function. I don't know if we have several stages of fresh vs recirculated air as mentioned by Jim Y, but I do know that a few minutes after starting the air-con on a hot day with a high fan speed selected, there is an audible change in the air path (not air speed as remember our fan speed control is manual). This suggests to me a change over of fresh vs recirculated air and that there is still some degree of automation in our "manual" system. My understanding was that normally, fresh air was used unless the recirc button was lit (this function self cancels after a period of time to prevent build up of stale air/CO2).

I'm probably getting off the track here with all my waffle, but the point I'm getting around to is that, to the best of my knowledge, our system uses refrigerated fresh air most of the time and copes with our Aussie climate in summer just fine (often around 40 degrees C). That is even in our '90 300TE which has 134a retrofit and the greater internal volume of the wagon to cool (although being a wagon, it has the larger version of the Nippondenso compressor). In the six years we have owned it I have had refrigerant added once. If ours works in our climate with refrigerated fresh air and that is the "failed mode" of yours, can you live with it in your climate?

I once had to make a similar decision with my '73 350SLC. One of the air direction flaps on the driver's side jammed preventing me turning off the heat on that side. I was faced with the choice of pulling the dash apart to fix it properly or simply disconnecting the linkage to that flap from under the dash which could be accessed fairly easily. The latter option (which I chose) simply means that when the heater is switched on for either the driver's or passenger's side of the car, the driver's side gets heat. There is also less progressive control of the heat on the driver's side. At the time I figured I could live with that fault until I had to pull the dash apart for something major. As it turns out, that was about 18 years ago! Nothing major has necessitated removal of the whole dash yet.

Again I ask, can you live with it until something really requiring removal of the dash such as the evaporator occurs? Not that I would wish something like that on you.

Greg

__________________
107.023: 350SLC, 3-speed auto, icon gold, parchment MBtex (sold 2012 after 29 years ownership).
107.026: 500SLC, 4-speed auto, thistle green, green velour.
124.090: 300TE, 4-speed auto, arctic white, cream-beige MBtex.
201.028: 190E 2.3 Sportline, 5-speed manual, arctic white, blue leather.
201.028: 190E 2.3, 4-speed auto, blue-black, grey MBtex.
201.034: 190E 2.3-16, 5-speed manual, blue-black, black leather.

Greg,

I appreciate and I enjoyed reading your response. Yes, of course, I am considering just leaving it. I don't think I will make that decision for another few weeks. In 2 to 3 weeks, maybe less, we will be dealing with high temperatures above 40 degrees C and low temps of about 32 degrees C.

I will drive it one of those brutal afternoons and see if it can keep up at all. I also must factor in the use of the car, which at this point is a backup, but I also use it for a long distance car since my primary is a very small, great handling but associated rough riding vehicle.

Occasionally I have to take a long, driving trip for business reasons. If one of those trips were to come up two weeks from now, I could always tape over 90% of the fresh air vent and make the trip.

All this sort of reasoning is a little too rational for me. As you correctly surmised, part of the motivation to tear apart the dash is that I want the car to be correct. Also, I am a terminal carnut. I don't do my own car work because I have to, I do it because of the satisfaction and pride that I feel from doing it myself. I know, that makes me pretty sick, a glutton for punishment I suppose. I rationalize this some by the fact that it seems that every time I get someone else to do car work I experience grief due to their incompetence.

In this particular case, I do have someone that I know could do this right, but is it worth it to shell out $800 or $1,000 to have it done?

I take pride in the mechanical condition of this car and how nice it is to drive. Cosmetically it doesn't look very good at all.

As for your manual climate control, there are many of us in the US who are very jealous. I have a European version 240D that I drove over a half million miles with good ol' manual climate control. It never gave any trouble that I couldn't fix in a few minutes and those times were very rare. I have posted before how much I would appreciate this car if it were manual everything right down to manual roll up windows. In the US I am very lucky to have manual transmission. Only about 300 of them made it to the US in '88 with a manual and I searched a long time to find it.

I still hope that someone will let me know if I can replace the right side pod from the glove box access. If I can, then I might be able to get it fixed with very little trouble if I'm really lucky.

Thanks Greg and everyone. Please keep the comments and violin music coming.

Have a great day,

Good morning all -

I did not pull the airbag or steering wheel when removing the dash. All the U.S. cars have the telescoping steering wheel; I just ran it all the way out. This makes sufficient room to pull the instrument cluster and remove the dash.

I think it took about three hours to pull the dash and center console. I don't think Larry is looking at more than 5-6 hours total work here. It's much simpler to replace the vacuum elements only as opposed to the evaporator. Dave (gsxr) should be able to give a good estimate of the work time, I know he's performed several pod-ectomies on 124 cars.

I don't know for certain on the 124 cars, but on other chassis the internals/mechanicals of the hvac system were identical worldwide; only the "front end" controls differed between the automated U.S. and manual systems used elsewhere. They all used the same vacuum elements, it was just a matter whether those elements were controlled by an automatic brain box or directly by manual switches.

- JimY

Hi Larry

Should you decide to go in and conquer the beast there is a plastic bell-crank that is associated with the operation of the Fresh/Recirc system which does break at times.

Just and FYI in the event you need to locate it: the bell-crank is located in the 201 HVAC parts system, I was unable to find it listed with any 124 information.

Good Luck

Well, I just called Phil and ordered the pods. I just can't make myself tape up the fresh air intake. I can't stand to have my stuff patched up with baling wire or tape.

I am tempted to start tearing it apart this weekend, but I would probably be better served to wait 'til the parts arrive.

I also ordered a new cap for my windshield washer reservoir. I wonder which will be the easiest job, replacing the washer reservoir cap or the pods?

Thanks for all your comments and please keep any suggestions or words of wisdom coming. I hope this does not just turn out to be a practice session for evaporator replacement.

I would rather do an entire engine rebuild than to do ANYTHING under the dash. At least it appears that I won't have to spend much time standing on my head for this one.

My brother in law, who is an dealership MB tech, insists that pulling the steering wheel is so easy to do that there is no need to leave it on. He insists that as long as the ignition is off there is no way that the air bag can blow.

I'm tempted to put it on the lift about three or four feet in the air. That way I can stand or lean over to get under the dash and climb into the car for the work over the dash.

Wish me luck,

I feel the same way.

Over the past few months I removed/replaced the dash in the '81 300D. It was alot less trouble than I had anticipated.

__________________
Jim

The Brown Truck left the set of vacuum pods today. I built the LED Pulse Counter tester and figured out how to check the Climate Control Unit for trouble codes. There are none set.

I wanted to do this before I started tearing everything apart in case there were a temperature sensor or something in there that might also need replacement. I don't want to do this more than once.

So, unless something else comes up, I'm going to aim every fan I can find at the front passenger compartment and start the project. We had our first 100 degree day today, so I'm sure this will be a sweaty project.

Wish me luck,

At the last minute (Thursday) I remembered that I had strongly suspected a leaking heater core sometime back and ran some bars leaks through the heater core. It has not leaked or smelled of antifreeze inside since. Because I have to pull the heater core to get to the floor flap pods, I ordered a heater core from Phil and got it Friday.

On Friday morning my boss called and said that we are having a meeting at his lake house in Missourri beginning on Tuesday. He said to bring swim trunks and golf clubs, so I guess he's just getting us together there so he can write off the lake house.

Anyway, it will be about 450 miles one way, so I decided not to tear apart the car this weekend. I planned on taping off the fresh air vent for the trip. I covered about 80% of the vent with metal film tape and gave it a test drive. It made little if any difference. I then taped it off entirely except for the little center screen. I think that the center screen is for the water drain only. I still saw no difference. I pulled the tape and ran another 10 miles or so and still no difference.

With a 96 degree outside temp, I was making about 46 to 48 degrees vent temp. That exceeds the performance test parameters in the MB manual.

Since I don't know and can't visualize the positions of the recirc doors, I don't know if taping the fresh air vent at the cowl is having the effect that I thought. After pulling the tape I ran it at speed with the climate control off and still got air through the vents. I should have tried that with it still taped to see if there was air through the vents.

Even with it 96 degrees I was quite comfortable, but this was all driving at speed on country roads. I think if I had to drive stoplight to stoplight it might not keep up.

So, I expect to do the podectomy next weekend assuming that our "meeting" is over.

Your experience and theories are still welcome and solicited.

Have a great day,

Larry,
As a brief aside & followup to something you just said, do you know the route of the water drain below & in the middle of the cowl screen? For example, do they connect to the a/c drains or act as a separate drain? Where does the water exit the car? Thanks.

__________________
87 300e (white/black; amg body kit)
88 300ce (red/cream; amg body kit)
93 300ce cabrio (white/blue/blue top)
93 300ce cabrio (black/grey/black top)
98 ml 320 (totaled @ 137,000 miles)
99 clk320 (black/grey/black top)

No, I don't know the water drain route, but maybe I will after this ordeal is behind me.

I drove the car 900 miles or so in the last three days. Unless I am in stop and go traffic in 95 degree ambient, it cools pretty darn well even with that hot fresh air.

Have a great day,

Larry,

If/when you start, I highly recommend taking digital pictures of EVERY fastener that might look like it could go back together a different way. Especially if a removable clip is involved, I found the pictures I took to be invaluable in figuring out what went where, and in what orientation.

I don't believe the pass. side recirc pod is removable with the dash in. There is a pod on the R side of the heater box that is for defrost and is doable, but I suspect it is a "hard" doable.

With the proper pages from the manual, the dash R&R isn't too hard, just very very very time consuming. It took me 18 hours over three days to do mine (for the first time), but I wasn't in a hurry.