Pagoda SL Group

W113 Pagoda SL Group => Electrical and Instruments => Topic started by: Jowe on March 01, 2015, 19:08:16

Title: Done maintenance of air & heater controls
Post by: Jowe on March 01, 2015, 19:08:16

As many of you have experienced, the air & heater control levers can be hard to adjust after may years of neglected service. Our Technical Manual has a very good description on how to disassemble and lube the air & heater control system. So did I. When I disassembled the control unit, the aluminium frame holding the levers cracked apart. Obviously, the frame had become vulnerable after many years (see first picture). I tired to put it together with epoxy, but it didn't last when mounting back in the car. My only chance to solve the disaster was to find a new(er) frame. I checked with the well known vendors of W113 parts but none of them sold the frame separately, only complete units with levers. My levers are in good condition and not needed to be exchanged so I turned to eBay instead. Luckily, i won a complete unit with cracked levers but the frame in good condition, at a reasonable cost. I switched over my controls on the new frame and mounted it perfectly in the car.

Lubing the control wires made everything moving easily, except the air distributor flap, which still was stuck. So I removed the air distributor box and found that the flap was stuck in the corners. Maybe the plastics has expanded somewhat since new. The mitigation was to grind off the corners and edges of the flap with a fine rasp. Eventually, the flap moved freely. Finally, this maintenance project was done  :)

Title: Re: Done maintenance of air & heater controls
Post by: Jonny B on March 02, 2015, 16:42:31

Wow! I don't think I have ever seen any kind of failure like this one. eBay indeed can be your friend.

Title: Re: Done maintenance of air & heater controls
Post by: batman on March 08, 2015, 06:33:43

Johan,

when  you say..."Lubing the control wires made everything moving easily"...what sort of lubrication did you use on the cables?

cheers

Title: Re: Done maintenance of air & heater controls
Post by: Jowe on March 08, 2015, 07:21:45

Mark,

I used WD-40 and sprayed into the cables.

Title: Re: Done maintenance of air & heater controls
Post by: Jack Jones on March 09, 2015, 00:30:50

Remove one of the cable ends from the control and install a piece of vacuum tubing over the end. Now insert the straw from a can of silicone spray over the other end of the vacuum hose making sure a tight fit and force the silicone into the cable. The results if dome correctly will move more freely then ever before.

Title: Re: Done maintenance of air & heater controls
Post by: ja17 on March 09, 2015, 00:39:48

I never saw a plastic frame, always metal in my world.

Title: Re: Done maintenance of air & heater controls
Post by: batman on March 09, 2015, 02:34:53

Jack -

Do you mean attaching an actual vacum cleaner and turning it on to suck the lub through?

Title: Re: Done maintenance of air & heater controls
Post by: Jack Jones on March 09, 2015, 02:51:11

Hi Mark,

I am referring to a piece of automotive vacuum hose than can be forced over the end of the outer casing of your heater control cables. Then use an aerosol can of silicone with a straw that will insert into the spray nozzle on the can and fit it into the open end of the vacuum hose. You want a tight connection so when you spray the silicone into the hose it is forced into the control cables between the wire and the outer plastic housing. 

Title: Re: Done maintenance of air & heater controls
Post by: batman on March 09, 2015, 10:44:35

Thanks Jack.

I am replacing all my levers in the coming months and creating a list of other things I should do at same time.

cheers

Title: Re: Done maintenance of air & heater controls
Post by: wwheeler on March 21, 2015, 12:47:08

I lubed all of my W111 cables including the hood release with this. Works incredibly well and these are available at most motorcycle shops. Not expensive either. You do have to put a rag on the other end because lube will come out.

http://www.motorcycle-superstore.com/4838/i/motion-pro-cable-luber

Title: Re: Done maintenance of air & heater controls
Post by: 66andBlue on March 21, 2015, 17:42:50

Hi Wallace,
nice gadget. Looks like having two screws to tighten the sleeve around the cable helps to push the cleaning/lubricating fluid down.
I have tried an earlier version that Michael S. advocated some time ago but sometimes the fluid leaked around the sleeve and would not go down the cable:
http://www.sl113.org/forums/index.php?topic=3345.msg19620#msg19620

Title: Re: Done maintenance of air & heater controls
Post by: wwheeler on March 21, 2015, 18:28:26

That is a similar device and maybe having the two screws is the secret or possibly a better rubber seal. The outer cable sleeve is a critical part. If is too big or small, it will leak. But the Mercedes heater cables should be in the size range that this device will work on. Worked before and I have my dash apart for a wood refurbish and I am going to do it again very soon. With a good seal, you will for sure be able to push the lube ALL the way through. So have the rags handy at the other end. Kind of fun too see the dirty old stuff come out.

I personally wouldn't use WD-40 as it is a so-so long term lubricant. A good penetrant and cleaner, but the lubricity goes away pretty soon. There are far better cable lubes in a spray. As hard as it is to do this process, do it right the first time.