Now that the weather up here in Minnesota is turning cold, I'm wrestling with a really stiff left side prop control on my Geronimo. It was this way last winter too. I've removed the turtle deck and cowling on the left engine and lubed it back as far as I can with Sil-kroil, with a small improvement. There is a lot of cable that is unreachable in the wing root cable tube and under the floorboards behind the heat ductwork.
Is it useful to remove the radio stack and try to get at it from behind the panel?
Is there a special attachment that clamps onto the cable so one can use a pressure can to blow solvent through it?
Can the innards of the cable be removed from the housing (vis-a vis the tach cable) so it can be cleaned and serviced and reinstalled?
You should buy a 1 quart pressure canister, either for a paint spray gun, or one used for oil. Hook up a regulator to supply between 5 to 15 psi air pressure to the cup. Attach a 3/8 inch x 30 inch long hose to the outlet. Remove your cables from the engine connections and place the end of the hose over the cable and secure with a hose clamp. Get a pint of Avblend and put it in the pressure canister. Start with 5 psi of air pressure to make sure you don't have any gross leaks at the engine. Then go to the control pedestal and move the control back and forth until you feel it free up. Put a rag under the pedestal too. You will smell the Avblend in the cabin when it makes its way all the way to the end. The cable will feel like new. Do this at each annual and you will never replace a cable again.
Or, you might check and see when the last time they were replaced. If they came with the plane when it was manufactured you might think about replacing them. Throttle, Prop and Mixture. Might want to look at NTSB report concerning N8828N. They were lubed regularly also, but....
McFarlene carries them, I think I paid $187.00 for each for my Arrow.
Thanks for the suggestions. I do have a pressure cannister I use for pressure bleeding the brakes- I never thought to use it for servicing the engine controls.
As for replacing the entire cable assembly- mine was manufactured in 1958 and all cable housings are original. The carb heat inner wires have been replaced a few times, and I just removed, cleaned and lubed the right tach cable-that was pretty easy to do. The prop, mixture and throttle cables are different, however. Like Glenn mentioned, the inner push wire cannot be removed. For that matter, the way the airplane was constructed makes it next to impossible to remove the entire cable assembly unless you are destroying the airplane. I've disassembled three Apaches and getting the engine control cables OUT was a miserable job- I can't imagine what getting them back IN must be like! They are nothing like a PA28.
Here's the update on the stiff control...
We used Stoddard solvent and the brake pressure tank set at about 10 to 15psi. It took us about 2 hours to get it worked out- just slowly working the prop control back and forth until it moved freely. In fact, it is now the loosest and smoothest of the six engine controls. Made a bit of a mess, but didn't stink up the cockpit like I was afraid it might. Annual comes due here in January, so I'll do the rest then.
Thanks for the handy tip, Glenn!
Happy New Year-
Mike Beard
