Same thing here...

I'm about to tackle this same project on my 88'

 

i believe John Roncallo did this with pictures somewhere

 

Look here Mercedes Benz 107 SL SLC Roadster Information Common Repairs Page Service Manual's
Mick

 

I did this two winters ago. My advise is to take your time. This is not a job for the squeemish. Label everything as you disconnect it. Also put screws and clips back in their holes / positions after you take each piece out or you wont know where they go later. I had to remove the dash to take out the heater box. Taking out and putting back the dash is a real SOB. Expect damage to your dash if your not extremely careful and patient. I would think though that bad diaphragms would cause issues with where the heat is diverted to, rather than stop heat altogether. I had a problem with heat intermittently and erratically working, that problem was caused by a failed monovalve.

 

Would you be so kind as to take pictures of the process, if possible? I, too have this job on my 'to-do list'. Filed under 'Insanity", of course.

Given its' complexity, a documentation of the process would be sure to make it to 'sticky' status.

 

Unfortunately I took the dash apart and put it back together about 8 months before I found this forum, otherwise I would have been certain to document the process.

Scary part is I put on about 200 miles driving around with the dash out looking for a body shop to do the work I needed on the blower compartment.

See PDF below.

http://www.benzworld.org/forums/att...3-1985-500sl-rust-repair-restoration-project-blower-compartment-restoration.pdf

 

Thanks for the information, Werner. I'm going to pull the console and glove box anyway to re-dye them, so I'll look very carefully for the problem and possible fixes before I pull the dash. I'd like to identify what the indy did to disconnect the heater, then I'll "reconnect" it and try to troubleshoot the problem without removing the entire dash.

I guess I'm fortunate in that my early 107 does not have automatic temp control or any of the complexity that comes with that.

 

may i suggest rmsmith's Homepage
click on the links to pics (most of them Roncallo's, used with permission). A lot can be done from underneath...

 

Been there three time now and it sucked all three times.

It's not too scary as far as it doesn't require too much brains. But it does require as lot of time and patience. Its well documented in the CD except the CD really describes the procedure for the 1972 model and was not updated for the 560SL which as a few extra switches that need to be unplugged and the mirror switch must be dislodged to get the center console wood off. Hears some pics.

 

More pictures.

 

great help with the photos roncallo. thank you.

i have a question, how did you manage to removed the tabs that hold the foam for the defroster flaps, im trying to push the holding tabs out but no luck !!

and how did you remove the defroster flaps off the shaft?

thank you

 

More pictures

 

And then about 1 years later it really sucked when I had to pull the heater box out of Samson again to re-wire the car.

 

Did you really get all those wires back in there in the right place, or did you cut 'em all out and hope they weren't really needed?:bowdown:

 

I've just removed the heater box from my 73, it's fairly straightforward process removing all the dash etc. My mistake was I thought I could remove the box in one piece and spent ages trying to manouvere it out. It doesn't work! you have to remove the bottom section first. once apart I found a comb inside that was jamming the flap open

 

Your a brave sole. While your in there, it may have just been a comb for now but if there is no history of vacuum pod replacement I would consider doing at least the two inside as they are in a very inconvenient location and they will break with age. Also remove the 4 screws holding in the Windshield Wiper transmission and replace them using new screws with Locktight.

 

This information is so helpful. Thank you to RM Smith, John Roncallo and Killbill.

From the comments of the previous indy I thought that the flapper valves were hinged with some sort of foam or organic material that had deteriorated and the valves were just sort of floating. From the pics, the hinges are mechanical and he was probably referring to the sealing foam that shows in some of the pics. Possibly the foam has deteriorated and is preventing the flaps from sealing or closing properly. It looks like if the foam needs replacement, the heater box must come out and I have no choice but to pull the dash.

So, the plan is to pull the console and glove box as the next step and see what I can do without pulling the dash. My intuition tells me that the dash is going to need to come out...if that's the case it will make it easier to clean up the filthy mess left from years of a seeping oil pressure gauge.

 

The vent pods all have a rubber diaphragm which may have decayed and torn. Most of those pods can be accessed by taking out the glove box and the instrument cluster. There is one pod inside the bottom section of the heater box which can be removed without taking out the dash. Be careful with all the plastic components can be very fragile with age.

 

If you decide to go in an take out the heater box, take a good look and consider what you want to replace while your putting things back together. You really don't want to do it again. My AC evaporator was really ratty, corroded and full of mouse nesting materials. The price of a good quality OEM unit from Autohaus AZ was $160.00. Even though I haven't hooked it up to the system yet because of other AC component issues, I felt that for the money and the labor to replace, it wasn't worth putting the old one back in.
Also change the O rings on the heater core connections. Make sure they are good quality, the rubber has to take a lot of heat.

 

Thanks Werner. Yeah, if I pull the heater box(es) I plan to replace pretty much everything. I do not want to ever do this again.

I think I know the answer to this question, but if I pull the heater box are the heater core and AC evaporators attached? Will I need to drain some coolant and also purge the AC system before heater box removal?

 

Yes they are. Both are actually inside the heater box. The heater core is at the bottom and the AC evaporator is at the top. You will have to disconnect the hoses to the heater core from under the hood by taking off the blower motor cover. Working in there will be easier if you take out the blower motor also. Cross your fingers you don't find rust in there.

You will end up spilling a little coolant as you pull out the heater core. It's unavoidable.

 

If I remember correctly I think I used a little GE black silicone roofing caulk to seal the seams.

 

.



Linked this thread in the E. Germanica after realizing we had nothing there regarding the several climate control systems. I'll keep this at the top of the page for a while so post any suggestions for inclusion HERE.

 

So essentially, I should wait to fix the HVAC when I decide to handle the rust repairs since all the seats, carpet, etc will have to come out for that too.

Are there any other fuses to the HVAC system other than what's in the fuse panel on the passenger side footwell?

Here's to hoping it's just a fuse!

 

Fix your rust first. The heater box won't rust.Taking the seats and carpets out is easy. Taking the dash out is painfully slow because you have to take pics, make notes in detail and label EVERYTHING . I used the little ziplock bags for each separate item and clearly marked on them.
Aside from the cluster there are not that many wires to actually disconnect.Most are plugs.The hardest bit is moving the remaining main harness wiring out of the way so you can remove the heater box and then pushing it back in place. I think that was the main unexpected impediment- that and flexing the dash.

 

I know this is a closed link, but would like to advise that the links at this site (mb107) for this particular issue (heater box repair) no longer function.

 

Do you still need info for heater box repair? I have lots of pics if you're interested.

 

Thanks, Aussie but no. This was only supposed to be about refurbing the dash, I really hadn't been paying attention to what was/wasn't functioning with the HVAC, so I don't know what needs repair and what doesn't. I do know that removing the heater box is beyond me (I couldn't get the clips under and behind to even budge) so I've just gone ahead and replaced what diaphragms I could get at. Managed to mess up more stuff, you know how brittle plastic gets in 30 years...I was only here on a "name that part" mission.

 

Tom can tell you if the part is even available anymore. Good place to source parts also. Join MBCA and get a 15% discount on parts. You will be assigned a local MBCA chapter and meet other MB enthusiasts. Really worth the membership dues.

Tom Hanson
Supervisor, Parts Operations
Mercedes-Benz Classic Center USA
MBUSA, LLC
thomas.hanson@mbusa.com
949 598-4842 direct.