New to me '65 M20C - Annoying radio mounting, water in my fuel, and other questions

[DCarlton]

 Looks like you ** might ** be able to upgrade to a more modern cap / fill neck assembly.  No idea what paper trail would be required.  Worth investigating.  I’m excited about the new caps and necks that come with the bladder kit.  It’s the little things.  

[jeremyc209]

59 minutes ago, DCarlton said:

I may have time to check the parts manual tomorrow too.  Theres a chance it’s the same part.  BTW, before I reconditioned my fuel caps I used to cover them with masking tape prior to any major rainy periods.  

Yeah I grabbed a set of those rubber cap covers off spruce since I didn't know how long it will take me to sort out the repair, they seem to be great quality and were holding on fine in the 38kt gusts out at the airport today when I swung by. The fuselage cover was hanging on for dear life but getting the job done 

[jeremyc209]

41 minutes ago, DCarlton said:

 Looks like you ** might ** be able to upgrade to a more modern cap / fill neck assembly.  No idea what paper trail would be required.  Worth investigating.  I’m excited about the new caps and necks that come with the bladder kit.  It’s the little things.  

Yeah it seems like most options aside from serviceable originals are very spendy. Stainless would be great but not for 800/wing in parts alone right now if I could even get them.

I wonder if I have something similar to that poster going on though, my left tank is pretty decent while the right side is pretty bad. I need to take a closer look. 

[AJ88V]

10 hours ago, DCarlton said:

We just removed the fuel cap flanges on my ‘67F to install bladders.  They come with new fuel caps.   If they are the same part, you can have them for the cost of shipping.  If interested I’ll make some pics.  I’ll need to make certain we won’t need the parts.  

That's an amazingly generous offer @DCarlton.  Good on you!!!

[DCarlton]

On 3/12/2025 at 9:52 PM, jeremyc209 said:

Yes! That sounds great, I'll look up the catalog for your F to compare part numbers and PM you. Thank you!

Two fuel cap adapter plates are on the way priority mail.  Sorry for the delay.  I had to check one more time to make absolutely sure we didn't need any of the parts for my bladder installation.  If you don't need them or can't use them, please pass them along to someone who can.  Good luck.

[jeremyc209]

Awesome! I bought a set of these cap covers to use in the meantime since we tend to have a lot of weather come through this time of year and they've definitely got a lot of good use already. (pic from spruce)

[jeremyc209]

Got the wingtips sorted. Some decent matching paint came with the plane.

Are these same switches available from spruce or elsewhere? The fuel pump switch is pretty "loose" in particular but a couple of them are getting there. 

My beacon occasionally doesn't work as well but I haven't confirmed if it's the switch. Wouldn't surprise me though. It's a strobe, not sure if they're prone to other intermittent issues. (It works without the other strobes on)

I secured a small hangar at my home airport though, one of the few private hangars came up and I asked around at the right time. The public hangars are probably a 5 year wait so I'm definitely happy!

[jeremyc209]

Anyone know what this is? Under the copilot side of the panel by right knee. Two red capped ports and another with clear PVC attached but it's just open under the panel, it doesn't attach to anything else. Small connector with a few wires and a "14v" sticker.

[Andy95W]

That looks like an avionics cooling fan.

[jeremyc209]

10 hours ago, Andy95W said:

That looks like an avionics cooling fan.

That makes sense, is the tube supposed to just dump air a little higher than the box but behind the radios? Seems like a lot of trouble to move air a foot or so in the same air space. 

[Andy95W]

Older avionics had/have a tube on the back of the rack that the hose would fit on.  Modern avionics tend to not need additional air cooling unless they’re being operated in significant heat like the desert.

It’s possible that the avionics shop that did some of the installations didn’t bother to connect the hose to any of the radios but just capped off most of the ports and pointed the one remaining to the backs of the whole radio stack.  Easier than removing a functioning fan that could still do some good.