Cowl flap indicator not working after annual

[epsalant]

I noticed after annual that the cowl flap on my 1989 M20J is not working well.  The cowl flaps themselves go all the way up and all the way down, but the indicator goes from all the way closed only to partially open.  The picture below shows how indicator shows the black indicator on "cruise" when, in fact, cowl flaps are all the way open.

How does the indicator work ?  Is it a cable or what ?  Any ideas what might be wrong.

Edited April 21, 2020 by epsalant

[squeaky.stow]

The black indicator is just the tip of a clear plastic rod that connects to a cable from your cowl flaps. If you are lucky, someone just forgot to reconnect it properly at the cowl flap end duRing your annual. 
If you are not so lucky, the clear plastic rod has become separated from the cable end just under the floor. They tend to do that after 30 years. It can still be repaired but it’s a bigger PITA. 
Lasar sells replacement parts for this.

 

[epsalant]

Which flap, Left or right, is it connected to? is this something I'll be able to see just looking through the bottom of the cowl?

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[squeaky.stow]

If you have an 89, I assume it has electric cowl flaps.

Should look something like this.

[epsalant]

Yes. I'll have to look carefully at diagram...

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[Vno]

I had a similar issue. Turns out the motor was broken (Shaft). It would close but airload would have cowl flaps trail open. On the ground see if you can move the cowl flaps manually (by Hand). If so my guess it the stops to make it shut off got misaligned and the motor kept spinning until it broke. 1992 J. If you are losing some speed in cruise I might believe the indicator is correct and the motor or linkage is broken.

For me it was a second rebuild at around $700. Make sure the stops are aligned correctly.

Brian

 

[epsalant]

10 hours ago, Vno said:

I had a similar issue. Turns out the motor was broken (Shaft). It would close but airload would have cowl flaps trail open. On the ground see if you can move the cowl flaps manually (by Hand). If so my guess it the stops to make it shut off got misaligned and the motor kept spinning until it broke. 1992 J. If you are losing some speed in cruise I might believe the indicator is correct and the motor or linkage is broken.

For me it was a second rebuild at around $700. Make sure the stops are aligned correctly.

Brian

 

On the ground I can see the cowl flaps work just fine, so I think the motor is fine.  When the flaps go up and down on the ground the indicator doesn't move, so I'm pretty sure it's an indicator problem.

[Keith20EH]

Reviving  this thread:

I now have the same problem in a ‘91 MSE, how in the heck do you get that cable out? The lower pedestal area that the indicator is in, looks riveted in, not sure how to proceed but think the “indicator” slipped off of the cable.  Anyone get in there yet? Or will I have to be first? I am not seeing how to do it.

[WilliamR]

Just went through this.  If the cable is well connected at the motor arm, then to get to the indicator plastic rod and its attach point to the cable you do have to take the center pedestal off.  Well part of it off.  As you note, the factory used some pull rivets to attach the pedestal.  So, you have to drill those out.  Looking back at my invoice it took a couple hours of work.  Note, I previously had good luck very carefully prying out the glass cover and reaching in to find the plastic indicator and just glued it back.  However, that repair lasted about 5 years.  The 2nd time it became disconnected, the indicator fell way down and the right side of the pedestal was disconnected to find it.

 

William

[Keith20EH]

Thanks for the reply, but I guess that is what I was afraid of..

[PT20J]

Updating this thread with my experience...

My indicator on my 1994 M20J broke. The acrylic plastic rod with the black tip is attached at the bottom end to a plastic slide that is moved up and down a slot in the mechanism by the cable attached at the cowl flap motor. The reason mine (and probably everyone else's) broke is that the slide is not centered with the channel in the indicator and this puts a side load on the acrylic rod which eventually causes it to break loose at the base where it is attached. Then it falls down to the bottom of the console. To fix this required removing the plastic cover of the console which requires removing all the nuts for various controls and drilling out a lot of pop rivets. The cowl flap position indicator and the wing flap/ trim position indicators are attached to this plastic console cover. I left the wing flap/trim indicator attached but removed the cowl flap indicator by removing the light bulb and two attaching screws. I could then pull the plastic cover aft enough to gain access to the cowl flap indicator mechanism and work through the front opening and glue the rod back to the plastic slide with some acrylic glue taking care to align it properly this time. To keep the indicator aligned while positioning and gluing the rod, I attached the plastic part of the indicator to the aluminum plate with double sided tape. This kept it in position until I could put the screws back in through the front of the console during reassembly. The picture below shows the rod after gluing to the slide and you can see the offset necessary to make it align properly with the indicator.

Skip

 

[Fly Boomer]

15 hours ago, PT20J said:

The picture below shows the rod after gluing to the slide and you can see the offset necessary to make it align properly with the indicator.

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