PT20J

How many threads are we going to have on this issue? We may set a record!

I believe most instances are from failing to close the latch completely before flight. On the models with an internal latch, it is possible to improperly reset this latch after use which might cause it to open in flight. Also, if the cover is missing it might be possible for something in the baggage compartment to shift and catch the latch.

The 3” extensions affect pedal angle moving the top of the pedals aft. My 1994 M20J has different master cylinders, but it looks looks like the technique I used would work on yours. Leave everything connected. Loosen the jam nut. Then you can rotate the shaft. There is a lot of leverage and I didn’t need to turn it more than a couple of turns. More info here…

Any that have the factory inside handle will open when locked from the outside.

No, but you are probably the only one who will admit it

Someone must make them — It seems pretty common for Cessnas to have one for an avionics master.

The GAD 27 provides power to 14V G3X/EIS during engine start brownout so you probably have to pull both breakers to shut down the G3X. But it shouldn’t have any other effect on the autopilot.

Just remember that those are circuit breaker switches, so you need to either find a different breaker/switch or install breakers with the new switches.

I had something similar initially. When pulling the G3X breaker, the G5 would not pass PFT an would show continuous PFT and PTRIM indications and so the auto pilot would not engage. Updating the software to 9.0 fixed it. You might have the dealer update (or reload if you already have the latest).

The GFC 500 has software in multiple components. The G3X and G5 contain part of the logic, and the servos contain part of the logic. The mode controller is primarily a user interface. So, when you pull the G3X breaker, it shuts down the autopilot because that part of the logic is now gone. You can manually restart the autopilot and it will now use the G5 logic in place of the G3X. You shouldn’t have to do anything with the AP circuit breaker. I don’t recall if the G5 PFT runs after a G3X power down, but if it does you will have to wait for it to complete before the FD or AP will work. Skip

I don’t know. My 1978 M20J had Klixons, and my 1994 M20J has E-T-As.

It’s really a good idea to examine the filter media. Lycoming has a service instruction that describes what to look for. Your friendly A&P may cut it open for you or loan you the tool, but the tool is not expensive. I used to carefully cut them open with a hacksaw which, if you are slow and careful, can be done without contaminating the filter media.

Doesn’t the yaw damper servo go beside the pitch servo on the same bracket that has to be installed for the basic autopilot?

If you are talking about the spark plug, Lycoming uses a special serrated helicoil to make sure it stays in place. There is a special tool to do it correctly. https://www.aircraft-tool.com/shop/detail.aspx?id=4260-18

There are usually some for sale on eBay.