Heater Cable Lubrication

[BigLou]

By removing radio and speaker, I have pretty good access to the heater/air control unit of my 1969 280SL. All the controls work, but they are somewhat tight, and I'd like to inject some lubricant into the cable ends, all of which are accessible. I literally plan to use a commercial (non-medical) syringe, after crimping the end of the "needle" to make it fit into the tight opening at the end of the cable. I do not have the skill or experience to remove the control unit or the cables for better access, nor do I know of a repair place for this operation. Some questions: (1) Am I crazy to do this? (2) What lubricant should I use? Remember that it must be thin enough to flow through a syringe with a crimped "needle." (3) The cables do work, so should I just "leave well-enough alone"? Thanks for any advice you can give me. Regards, BigLou

[Jonny B]

Go to the main search function (the one in the row of items beginning with "Home" (this will search the entire forum). On the search page use - heater cable lubricant. You should get a single page of the different approaches others have used.

[BigLou]

Jonny, good suggestion and helpful, but no definitive answer except not to use WD-40. The cable that operates the heater core valve and driver-side heater air flow is the easiest to reach. I think I’ll try that one first to see what happens. Maybe I'll try PB Blaster as the loosener/lubricant. Thanks.

[wwheeler]

Try this. Works very well.

https://www.youtube.com/watch?v=NG6JO9f0Q6U

I have used a similar brand on my cables.

[BigLou]

Wallace, thanks. To use that device I'd need to release the cables from the notorious "wheels" that move them, and I don't have the courage to do that. I do have the lubricant shown, which is PJ1. I think I'll inject that into one of the cables and see what happens. I'll be relying on gravity to distribute the product throughout the cable. Another thought I've had is that stiff cables may result more from stiffness in the hinges they move (and, in the case of the lower passenger-side control, the heater core valve it also moves) than from the cables themselves. This thought occurred because of a forum post about a cable that loosened whenever the heater warmed up the hinges, and also because I have not had issues with the cables that open the hood and the soft-top compartment (knock on wood).  Regards, BigLou

[BaronYoungman]

I have used clock oil, they come in little syringes (pen oiler) you put a drop or two each day for 2 days then put some and work the lever seems to always work for me.  You use the needle part of the syringe and get it in between the rubber and cable... gravity does the rest. I do not remove from the wheels you just have to be flexible with the oiler. I get mine from Chicago Clock Company, they ship also.  1-800 771 2347. 

[BigLou]

Baron, thanks. I have something called Tri-Flow Pin Point Lubricator that I use for other things. I'll bet it's similar, though it doesn't mention clocks.

[mdsalemi]

https://www.youtube.com/watch?v=NG6JO9f0Q6U

If you do a search on Amazon for "Cable Lube Tool" you'll come up with a variety of similar items of similar design, all around a $10-$14 price point.
I used to have one (albeit a bit smaller I think) in my bicycle shop that I ran as a kid back in the 1970's so this is not new technology. They worked well, despite the fact that some reviews of these on recent forums call them snake oil...there are some people so darn cheap that they'd rather fumble around with baggies and home brew devices than buy the purpose made tool for the job for $10. We'd use Tri-Flow, WD40, or LPS3, run it until we saw some come out the other end--then we knew we had full penetration of the lube into the cable. Worked very well, and it wasn't a costly tool then or now.

Then, at one time some company came out with what they called "ultra glide" cables for bicycle brakes. They cable was coated with teflon, and the housing lined with it. They were absolutely perfect, albeit a bit costly. I still have them on my bicycle, some 40+ years later. Yeah, it's a vintage road racer!

[BigLou]

Thanks Michael. I'd use the bicycle tool if I had the ability to R&R the cables. I'm sure I could manage the first R, but the second R is where I'd leave a mess.

[Jack Jones]

I have had really good success placing a piece of vacuum hose over one end of the cable, inserting the straw from a can of silicone lubricant into the open end of the vacuum hose and spraying into the cable forcing it through the cable. If this does not free them replacements are cheap from MB. 

[BigLou]

Jack, not sure what a "vacuum hose" is. I agree that the parts are not expensive, but I'm not capable of installing them, and I'm not sure anyone near me is capable. Technicians trained in this 1960s heat/vent system are few and far between. The closest to me are in Atlanta and, possibly, Houston. Regards, BigLou

[Jack Jones]

BigLou,

When I say vacuum hose I am referring to the small diameter rubber hose used in areas such as the advance mechanism on the distributor. You need to remove one of the ends of the cable, force the hose over the outer plastic portion of the cable then use the straw on an aerosol can of silicone lubricant in the rubber hose. Keep the rubber hose sealed around the straw and spray the lubricant forcing it into the cable.

I have no experience with Buds Mercedes in the Atlanta area but they specialize in most models of older Mercedes. Others in this group can most likely provide feedback on Buds.     

[BigLou]

Got it Jack. Thanks. I'm now thinking of accessing the cables where they attach to the flaps. Your method would work great there. I'm about to launch a post asking how I can access all that. Regards, BigLou