PC Wing lever

[WPrince]

Recently purchase a 66 M20C and am looking and tracking down the issue to why its not working. I have opened up the servo compartments and found the rubber boots to be in good shape (pictured). But I looked underneath the panel to see the vacuum lines conditions and found this line extremely cracked line and it had fallen off. It does look like all the lines have been updated in the last few years. Obviously this will be replaced but trying to understand the system more. Looked at every diagram and trying to understand where this line even goes! 

[carusoam]

Welcome aboard WP!

You have found the first of many things age does to that system…

There are threads around here how to handle the rest…

 

There are collectors of old parts if you want to buy replacements… find @Alan Fox

The Brittain company also still exists… they sell new tubes and such, but not much else…

Best regards,

-a-

[WPrince]

I have read about all the forums, I just can fully figure out which part I am looking at and where it goes. I appreciate the contact for Alan Fox as well, I will reach out.

[carusoam]

5 minutes ago, WPrince said:

I have read about all the forums,

This is quite a task…

It has taken me several years to read all of the forums… 

 

Are you looking for a tubing diagram?

or manuals for the Brittain system?

 

Or just this one tube became disconnected?

 

What boxes do you have that came with your system?

 

What do your logs say about maintenance for your installed equipment?

 

Expect to have to write a lot of detail….

Best regards,

-a-

 

 

[RLCarter]

I have the Britten Manuals I can send you which will help…send me a private message with your email and I’ll get them out to you this evening when I get home

[takair]

Looks like your gyro. One line goes to the filter and the other to the vacuum regulator….

[WPrince]

Just looking for the information on where everything goes, not a ton of information. Just trying to track down the system and see what is going on as I cannot get it to work at all. I bought the plane and the owner passed and sold in an estate sale. A local mechanic tore it down and pretty much rebuilt every thing, new motor/prop, avionics and rebuilt the PC wing level and that is why all my vacuum lines are pretty new. 

That diagram above really helps! Was that from Brittan? 

[FlyingDude]

Sorry to hijack your post, but it reminded me of something that I've been meaning to ask:

What's that lamp that I circled in blue? Thank you

[WPrince]

I just discovered that while I was underneath, going to start following the wires, not a clue

[carusoam]

If you are under the instrument panel…

That light is pointing right at the fuel selector valve…

Most people probably don’t know it is there…. Its bulb may be original.

Probably gets used on a familiarization flight after dark once…. 

Best regards,

-a-

[FlyingDude]

4 minutes ago, carusoam said:

Most people probably don’t know it is there…. Its bulb may be original.

I've logged many night hours with my plane but I have to admit I haven't noticed it. Thinking back, I didn't recall having to switch tanks in the dark either. It might even be broken! Is it driven by nav lights switch?

[211º]

@WPrince See this link: https://www.windfield.farm/positive-control for a bunch of information that I've curated from MooneySpace.  That cracked hose is (not kidding) windshield washer hose. 3/16 or 3/8", I can't recall. There are also areas about altitude hold and heading hold on that site

[Guest]

The fuel selector light is controlled by the light rheostat.  It also has an adjustable aperture to dim it further.

[AIREMATT]

11 hours ago, WPrince said:

Recently purchase a 66 M20C and am looking and tracking down the issue to why its not working. I have opened up the servo compartments and found the rubber boots to be in good shape (pictured). But I looked underneath the panel to see the vacuum lines conditions and found this line extremely cracked line and it had fallen off. It does look like all the lines have been updated in the last few years. Obviously this will be replaced but trying to understand the system more. Looked at every diagram and trying to understand where this line even goes! 

 

 

I have a 67C that looks about the same. I’ll see if I can get under there with my camera Tuesday or Wednesday and get a couple pix to compare for you.
Dan

[FlyingDude]

13 hours ago, M20Doc said:

The fuel selector light is controlled by the light rheostat.

Thank you.  I think I'm going to replace it with an LED, along with the red and green gear bulbs and overhead red lights.  The ones I opened up draw 1A, I've noticed.  We're talking 4A in lights already.  They get hot and amount to 8% of generator output...  

[WPrince]

17 hours ago, 211º said:

@WPrince See this link: https://www.windfield.farm/positive-control for a bunch of information that I've curated from MooneySpace.  That cracked hose is (not kidding) windshield washer hose. 3/16 or 3/8", I can't recall. There are also areas about altitude hold and heading hold on that site

Some great info there, looking more and more into it I found that the line only going into the filter. I finally found this schematic and looks like 65, 66 and 67 were all a bit different in the design, going to starting down any vacuum leaks.

66 Schematic.pdf

[AIREMATT]

4 hours ago, WPrince said:

Some great info there, looking more and more into it I found that the line only going into the filter. I finally found this schematic and looks like 65, 66 and 67 were all a bit different in the design

I guess mine is different. It’s a 67 built in 12/1966 but it looks like different plumbing hookups. I only see Red and Green, no white tube. Not even sure I have the rudder servo plumbing. Haven’t found it yet anyway…

[WPrince]

35 minutes ago, AIREMATT said:

I guess mine is different. It’s a 67 built in 12/1966 but it looks like different plumbing hookups. I only see Red and Green, no white tube. Not even sure I have the rudder servo plumbing. Haven’t found it yet anyway…

Here is the file for 65-67, found it to be very helpful information. Looks pretty different than what I am running underneath. 

65-67 PC.pdf

[carusoam]

10 hours ago, WPrince said:

Some great info there, looking more and more into it I found that the line only going into the filter. I finally found this schematic and looks like 65, 66 and 67 were all a bit different in the design, going to starting down any vacuum leaks.

66 Schematic.pdf 186.84 kB · 6 downloads

1965 was a major overhaul year… every system got touched, added, or changed…. It was the first year for the wing leveler on every Mooney…

Every year after that included more adjustments…

The 65 wing leveler used a separate gyro in the back to operate the Brittain system….

Newer systems used a Brittain TC mounted on the panel….

-a-

[Bob R]

On 1/18/2022 at 4:29 PM, WPrince said:

Here is the file for 65-67, found it to be very helpful information. Looks pretty different than what I am running underneath. 

65-67 PC.pdf 788.22 kB · 5 downloads

The Red and Green tubing indicate the wing it feeds. When I overhauled my PC system, I needed to replace the left wing tubing which runs to a T behind the left-hand baggage compartment panel. Could not find a smaller quantity of the Parker red tubing for the left wing so used opaque and marked it with red electrical tape.

[WPrince]

So I would like to update this for anyone that finds themselves in a similar situation, 66 model Mooneys had a separate "remote" gyro installed on the pilots side underneath the panel which can also be accessed through the outside of the plane from a panel located between the main top engine cover and the windscreen. In 1967 Mooney installed the gyro into the turn coordinator. If you have the trim knob on the yolk, you have a remote gyro. Porter Strait Instrument has a past employee of Britain that built these levelers working there with great knowledge and will still rebuild some of these units. The simple way of testing the system is to apply suction via mouth to each of the red and green lines, you will see the yolk move to one side with red and back the other way with green. I found that red was just fine, green couldn't hold vacuum. Both red and green have a T in the line and that is located in the baggage area behind the interior paneling. (the panel farthest from you looking into the baggage area). This T has line going into the tail servos (which can be access through the tail inspection panel on the pilots side) and the other is routed directly to the ailerons. After disconnecting the T you can vacuum check both the tail and ailerons vacuum for leaks. I very quickly found a leak on the green side of the line in the tail servos rubber boot hidden on the back side. I've been told people have had success using bike tube repairs. I'm going to have the boot replaced (hopefully). Hope this helps anyone out there with similar issues. After many many hours of research, calling around and talking with some guys I feel like I know this system almost like the back of my hand now. To anyone searching around and looking at the maintenance manual(highly recommend on in the download section), be very specific with what year of the diagram you are looking at because they are all lumped together.

Also replacing the o-rings inside the push button cutoff valve in the yoke will make a great difference and that simply just pops right out by hand.

For my original post the black cracked line goes into a vacuum filter located behind the pilot side paneling.

[carusoam]

Nice follow up WP!

Best regards,

-a-

[65MooneyPilot]

When I first bought my Mooney the PC system did not work and it took me approximately 5 years to get it going. I started with the gyro and had it overhauled. Then I found I had plastic servo cans that were completely cracked out, so I got a new set from Britten and changed the red tube in the left wing because of cracks in the wheel well. So at that point my system was tight and still not working. The next step was the pressure relief button on the yoke. I changed the O rings and that sealed it but did not fix it. I took the clock out and while flying I stuck a pencil in the grey vacuum line and the PC started working so then I knew the yoke button was the problem. However the problem turned out to be the holes where they are drilled in the yoke itself. The plastic on the yoke was pealing off so I removed it and saw the metal tape used under the plastic had fallen off under the cracked plastic and exposed the drilled holes. I removed the yoke and installed set screws in the holes, had the yoke powder coated and the PC system has worked ever since. 
I used a hand vacuum pump with a gauge on the servos instead of my mouth and that worked for me. 

[Bob R]

3 hours ago, 65MooneyPilot said:

When I first bought my Mooney the PC system did not work and it took me approximately 5 years to get it going. I started with the gyro and had it overhauled. Then I found I had plastic servo cans that were completely cracked out, so I got a new set from Britten and changed the red tube in the left wing because of cracks in the wheel well. So at that point my system was tight and still not working. The next step was the pressure relief button on the yoke. I changed the O rings and that sealed it but did not fix it. I took the clock out and while flying I stuck a pencil in the grey vacuum line and the PC started working so then I knew the yoke button was the problem. However the problem turned out to be the holes where they are drilled in the yoke itself. The plastic on the yoke was pealing off so I removed it and saw the metal tape used under the plastic had fallen off under the cracked plastic and exposed the drilled holes. I removed the yoke and installed set screws in the holes, had the yoke powder coated and the PC system has worked ever since. 
I used a hand vacuum pump with a gauge on the servos instead of my mouth and that worked for me. 

If you are interested, I have 2 pilot side yokes I am interested in parting with. Both are freshly powder coated in the off-white. If interested, make me an offer and I can send you pics.

[65MooneyPilot]

My yokes are already powder coated, but maybe someone is interested.