Heater control lever replacement

[coloradoconner]

How does one go about replacing the 4 heater control levers?  Mine are all broken up and I have the replacements, but...

[Richard Madison]

Requires getting into the dash area...it's a difficult job only because the space is so tight...there are a few hidden screws. Took me and a helper about 6 hours...we both had scratched wrists.

Also a good idea to replace the dash lights, instrument seals, etc. as long as you are in there.

The Tech Manual has a step by step with pictures.

http://www.sl113.org/wiki/pmwiki.php?n=Electrical.ReplaceHeaterLeavers

Richard M, NYC

[ja17]

There are some aftermarket replacement levers engineered to be installed through the front without any dis-assembly. Takes about an hour. They look different but work most of the time. A good temporary fix or they can be left in if you are not into originality.

The name is Duralever, I believe.  You can look at the installation instructions on their web site.

[coloradoconner]

quote:Originally posted by 280SL71

Requires getting into the dash area...it's a difficult job only because the space is so tight...there are a few hidden screws. Took me and a helper about 6 hours...we both had scratched wrists.

Also a good idea to replace the dash lights, instrument seals, etc. as long as you are in there.

The Tech Manual has a step by step with pictures.

http://www.sl113.org/wiki/pmwiki.php?n=Electrical.ReplaceHeaterLeavers

Richard M, NYC

Thanks for the information and great pictures.  Since I have the replacement levers, I'll try diving in to replace them.  The tips on replacing lights, etc are good ones, I will be sure to check those.  Won't be able to start on it until mid-July but planning ahead is necessary.

[rwmastel]

quote:Originally posted by coloradoconner

The tips on replacing lights, etc are good ones, I will be sure to check those.  Won't be able to start on it until mid-July but planning ahead is necessary.

If you consider pulling out your instruments, first do a Search on "capilary tube".

[johnshenry]

Dredging up a very old, but probably well read thread.  I will have to do this job on my '69 280 soon.  I have the replacement levers already.  My questions are:

How accessible are the other ends of the cables?  That is, can the 4 cables be fully removed from the car so they can be properly cleaned and lubed?  I have no intentions of doing this job unless I can make the cables move very freely.  I already saw the how to on the heater core valve/cable removal, so I know where the end of that one is. 

I presume that the other other 3 cables are just flap operators and must be pretty short?

Lastly, I may not be able to get to this job before my wife and I take the car on a 3 day weekend to Vermont.  The heater valve is stuck open and the levers all broken off.  Is there a way to manually operate the heater valve, maybe from inside the engine bay?  I saw the pics of the rubber cover, could it maybe just be hand rotated with some pliers via that hole?

My thought is we won't need the heat in May, but if I shut it off and we get some cold weather, it would be nice to be able to turn it back on.

Thanks for any advice.  I am not going to tackle the lever job unless I have a HUGE pile of patience, and no deadline to finish it.............!!

JH

[Wes Bender]

The fresh air flap cable (upper left lever) is accessible after you remove the hood scoop and loosen the air flap. The left and right heat control cables (the bottom levers) attach to flaps that you can access  after removing the fresh air control flap and the filter element.  The one that will require the most work is the cable that directs air to either the lower openings or the defrosters (upper right lever).  You will need to remove the air distribution box (just below the blower assembly) in order to access it.

For your immediate problem, you might try to manually turn the water tap off through the round access hole in the firewall.  Or, if you wish, you can cut the hose that feeds hot water to the heater core and insert a ball valve temporarily.

The heat system in my 280 SL has elicited the comment "What were they thinking?" from me many times.    Works great new.  Was never designed to be maintained in its old age.  (I just finished replacing the heater core a couple of weeks ago.)

Cheers,
Wes

[bpossel]

JH,

Does your car have air-conditioning? This makes access more difficult, especially for the lower control cable that connects to the flap on the cage.
Bob

[johnshenry]

No, no A/C in mine.

I recently got a copy of the MB "Blue" book but have not perused it yet.  Does it cover this replacement and details on all the cables and such?

[Bernd]

They are not that difficult really.. Just tedious. While you are at it, clean the assembly and lube the wires in the cables.

Bernd

[bpossel]

Wes,

I am afraid that I cant be much help here.  I replaced the cable to the distribution box (cage) while it was out of my car during the resto.  I installed the cable in the box and then installed the box in the car.  Not sure if the cable can be replaced without removing the entire box/cage?

Has anyone replaced the cable with the distribution box still in place  

Bob  

[johnshenry]

Thanks for the pics, those will be helpful.  So the "cage" refers to the big box that the blower attaches to, and the "control" unit its the thing up top that the levers are part of?  How hard is it to get the cage out?  My car is fully assembled now, but I really only want to do this once.  I had heard too that having the blower motor refurbed is s good idea?

[Wes Bender]

Wes,

I am afraid that I cant be much help here.  I replaced the cable to the distribution box (cage) while it was out of my car during the resto.  I installed the cable in the box and then installed the box in the car.  Not sure if the cable can be replaced without removing the entire box/cage?

Has anyone replaced the cable with the distribution box still in place  

Bob  

I don't think there's any way to disconnect the cable without removing the distribution box.  You have no access to it while it's in the car.  On my recent rebuild of the entire system I cleaned everything up and lubricated that particular cable without disconnecting it, but it was out of the car.  I would add that, while everything in the system was dusty and the various foam gaskets had turned to dust, due to the car being in Arizona and New Mexico its entire life, nothing was corroded.

I would also add that I'm retired and could devote as much or as little time as I wished to the project each day.  I can't imagine the frustrations involved in doing that complete job on a tight time schedule.

cheers,

[graphic66]

I have used this tool for years to lube all my cables.  http://www.motorcycle-superstore.com/1/4/65/4838/ITEM/Motion-Pro-Cable-Luber.aspx  This tool is a must have for you gadget  addicts out there. It really does the job.

[Bernd]

Great find..love the design!

[johnshenry]

Yeah, I'll have to get one of those cable lubers.

I think I am specifically NOT going to start this job before we take the car away in early May..... as Wes said, this is NOT the kind of thing you want to do when there is any kind of time pressure.  I think I will just try to wrench the water valve shut from inside the engine bay and pray for warm weather.  If the valve is free, I can bring tools and wrench it open on the road if need be (to reduce wife-whining).

2 Qs about that water valve:

Do I understand that you can just pop that cupped cable end off the ball on the valve lever?  Just an interference fit? 

And if I really have to, can I pull the valve core without draining the coolant (cold engine)?  I found a good pic series on that in the tech manual here.  I see no reason why the coolant would need to be drained, its definitely the high point in the system.  If the valve is corroded open and I have to pull it to make it operable, I may do that.....

[bpossel]

Yes, just pop it off, unless its rusted on...  then will require a bit more effort.... but just a ball & socket design...
Yes, you can remove the valve w/o draining the fluid.
Just be really careful when removing the valve.  Dont let it fall into the core...  follow the steps in the Tech Manual and ask questions in this forum along the way.
You also may want to plan ahead and buy a new rubber o-ring and some plumbers lube before you pull the valve...
Bob

[johnshenry]

Thanks.  Yeah, I saw the precautions about making sure you don't drop the valve.  Good write-up and tips.