Fuel Selector Valve Rebuild?

[wrench]

Need your help please,

Anyone have recent experience with replacing or overhauling the Fuel Selector valve on the M20J. My A&P tells me it needs replacement or overhaul because you can't feel the L or R position detents anymore. Since I have owned the plane I never could feel any detents when changing selector positions but the high friction load on the selector valve handle pretty much guaranteed it wasn't going to move anyway. It takes about double the continuous effort to rotate the valve when changing tanks from what I'm used to when comparing to a Piper or Cessna's fuel selector valve. With as much effort as it takes for rotation I doubt a spring loaded detent could be felt anyway. At least in my plane.

So here's my questions,

#1 Do the Mooneys you boys and girls have experience in have definable detents that can be felt in the Left or Right fuel selector positions? Mine doesn't that's why I'm asking.

#2 Does anyone know of a source that reconditions or has replacements for these fuel selectors or even may have parts for a field rebuild?

Thanks for any help you can provide,

Bill

[Hank]

My C has distinct detents at all three positions. I think it is the older, non-rebuildable style. :-(

Still no emoticons, but I can post with my Droid phone now.

I'll be interested to see what happens.

[wrench]

What year is your J? Dan at LASAR rebuilds many of the fuel selector valves used in Mooneys. He won't or can't rebuild the fuel selector valve that was used when my 201 was made in 1978, however. I'm not sure why. A kit is available to upgrade to a later model, but it is around $1,500.00 and is not a direct bolt on replacement. Calling him to discuss might be a good place to start.

Jim

Jim

I have a 78 J model 24-600

Thanks for the reply,

Bill

[wrench]

Hi, Bill. Mine is 585. You've probably got the same valve I do. FWIW, my valve's friction feels about right to me. A little on the stiff side, maybe, but not too much so. I can feel a detent on one side but not the other, but it's operation has always been reliable and my mechanic recommended leaving it in service.

Jim

Thanks for the info Jim.

[Rainman737]

Hi Bill, I have a late model J, 24-3356. I can feel detents in all 3 positions. Is yours weeping or leaving any stains that you can see with the belly pan off?

[wrench]

Hi Bill, I have a late model J, 24-3356. I can feel detents in all 3 positions. Is yours weeping or leaving any stains that you can see with the belly pan off?

Not leaking. The A&P tells me the fact that you can't feel the detents is cause for rebuild or replacement. This is the first Mooney I ever owned and since I never could feel any detented positions on the fuel selector I wondered if it was a normal condition or not. It sounds like Lazar might have a solution but they are asking for more make, model#, serial# etc. fuel selector valve information before they can answer on replacement or overhaul. I will have to get that info on Monday since the plane is locked in a service hanger for the weekend.

Thanks for input.

[Guest]

The manual provides no information on repair of the valve.  However LASAR does them if your maintainer won’t take it apart and fix it for you.

Clarence

[A64Pilot]

I wouldn’t worry as much about detents as I woud if it’s real stiff to move.

[carusoam]

4 hours ago, philip_g said:

Moves real free but I don't like that it's super easy to move from left to off.

What mechanism causes the detents?

Possibly springs and ball bearings…. It’s been a while since I have seen them…

My M20C was missing the detents… and you never know if the valve is in the right place or not without them….

When the valve moves freely…  it may possibly move on its own when bumped…. (Not a very common occurrence….)

 

There are probably pics around here somewhere…

PP thoughts only, not a mechanic…

Best regards,

-a- 

[Guest]

11 hours ago, philip_g said:

Moves real free but I don't like that it's super easy to move from left to off.

What mechanism causes the detents?

There is a plate with the detents inside the valve.  Mooney used a number of different part numbers and designs over the years.

Clarence

[EricJ]

On 9/15/2012 at 11:32 AM, wrench said:

Not leaking. The A&P tells me the fact that you can't feel the detents is cause for rebuild or replacement.

FWIW, that's not an unreasonable position.   The FAA Airplane Flying Handbook (8083-3B) says that a lack of detents in the fuel selector is unacceptable in a preflight inspection (p2-3).   The NTSB published a Safety Alert a couple of years ago citing fuel selectors and detent wear as issues.

https://www.ntsb.gov/safety/safety-alerts/Documents/SA_076.pdf

 

[ilikethewoods]

Just throwing my little 2cents in. When switching fuel tanks, ya can 100% feel the detents in the selector valve. Mine was leaking, sent it to LAZAR. He rebuilt it for a reasonable price. He even extracted a screw that was broken off in the valve. Worth getting a quote. Stay up.

[Ragsf15e]

Just a laymen’s perspective, but that thing is a single point of catastrophic failure.  If it’s questionable, I’d definitely dig into it.  If something isn’t right and it comes loose when you’re switching tanks, it could get really quiet.

[Andy95W]

20 minutes ago, Ragsf15e said:

Just a laymen’s perspective, but that thing is a single point of catastrophic failure.  If it’s questionable, I’d definitely dig into it.  If something isn’t right and it comes loose when you’re switching tanks, it could get really quiet.

Didja ever count up the number of “single points of catastrophic failure” we have in our Mooneys?  Single pilot, single engine, single pushrod to the elevator/aileron/rudder, single throttle/mixture/prop control?  How about your one fuel line to your one fuel filter to your one Bendix fuel control unit to your one Bendix fuel divider, any of which can shut down your one engine?  The list goes on and on.

I agree with the need to perform proper maintenance.  Trying to exaggerate one point of failure as more scary than any of the others is a bit disingenuous. 

Edited July 6, 2021 by Andy95W

[Ragsf15e]

2 minutes ago, Andy95W said:

Didja ever count up the number of “single points of catastrophic failure” we have in our Mooneys?  Single pilot, single engine, single pushrod to the elevator/aileron/rudder, single throttle/mixture/prop control?  How about your one fuel line to your one fuel filter to your one Bendix fuel control unit to your one Bendix fuel divider, any of which can shut down your one engine?  The list goes on and on.

I agree with the need to perform proper maintenance.  Trying to exaggerate one point of failure as more scary than any of the others is a bit disingenuous. 

Oh yeah, I realize there’s risk.  I definitely accept some.  Just try to minimize where i can.  I fly over big mountains in the northwest, but I tend to do it in daytime and vfr.  I’ll also modify the route to minimize the time but sometimes you gonna accept the risk.  However, if my fuel selector, elevator pushrod, mixture, bendix, etc isn’t working right, I think I’d be more apt to get them fixed immediately vs maybe my VOR 2 or even flaps not exactly being right.

[Mooneymite]

51 minutes ago, Andy95W said:

Didja ever count up the number of “single points of catastrophic failure” we have in our Mooneys?

 

One is the lonliest number..

https://youtu.be/d5ab8BOu4LE

 

[Guest]

2 hours ago, philip_g said:

Btw LASAR said they can't touch this valve. They can overhaul the one between your knees but not the one behind the pedestal like mine

Take it apart and fix it.  It really can’t be too complicated.  Here’s one from EBay you can practice on.

https://www.ebay.com/itm/123927800261?hash=item1cdaac29c5:g:sMgAAOSwBY5dlYI1

Clarence

[PT20J]

Don Maxwell repairs a lot of stuff others won’t touch. 

[carusoam]

12 hours ago, philip_g said:

@Dmax

Can you guys overhaul the 201 selectors That aren't between the pilots knees?

Often @Pmaxwell might be a better contact around here… (DMax Jr…) 

And if that doesn’t work….  Phone number listed….  https://www.donmaxwell.com

Best regards,

-a-

[Joe Larussa]

Send it to Dan at Lasar. Turned mine around in a few days. Easy to remove and reinstall. Detents where they should be and no leaks. Was around 300.00 if I remember correctly.

[Raymond J1]

For olds Mooney's :

The difficulty of operation of the selector originates from the friction of the axis in its bore, there is a small O-ring in this upper guide.

The distribution plate has 4 indentations and there are two indexing balls (pushed by springs into the indentations of the plate) for each position (2 in the model of the photo), it is the fouling of the springs in their housing that no longer allows the indexing function.

This system is simple, but it must be cleaned and restored with great care.

The PTFE seals, mounted on the selection plate is the essential part since it is on these parts that the sealing of the interconnection rests (no air passage in case of empty tank).

The small O-ring in the bore is also important. The geometry of the distribution plate, the surface condition are elements to be checked after disassembly to know if the parts can be reused.

Mechanically, this is done well because it is not possible to switch left and right in a winding negligence, the red mark of the lever would be in the wrong direction.

 

Edited July 15, 2021 by Raymond J

[carusoam]

Great pic JR!

I have not seen the inside of those parts before…

Best regards,

-a-

[Ragsf15e]

Quick question about fuel selector valves since I'm studying for my annual in a couple months...  Mine hasn't been R&R'd or overhauled since May 2012, about 800 hours.  I just found the below tidbit in the mx manual.  Do you guys R&R them at 500 hours or so?  It seems to work ok...

Thanks!

[EricJ]

1 hour ago, Ragsf15e said:

Quick question about fuel selector valves since I'm studying for my annual in a couple months...  Mine hasn't been R&R'd or overhauled since May 2012, about 800 hours.  I just found the below tidbit in the mx manual.  Do you guys R&R them at 500 hours or so?  It seems to work ok...

Thanks!

I'm a believer in avoiding unnecessary Maintenance Induced Failures, so I'd say if it's not leaking, it works, the handle moves freely, and the detents are functional I think I'd leave it be.   

 

[carusoam]

Eric nailed it!

Leaks…

missing detents…

Slightest binding…

All good reasons to have serviced…

 

When fuel is leaking out when not flying… Air has the tendency to leak in while flying… the FF indicator usually starts to show funky higher than normal numbers…

The only jammed fuel selectors, a very serious challenge in flight…. Have given hints of trouble by not operating smoothly…. Take the hints seriously…

 

PP thoughts only, not a mechanic… stuff I read about on MS…

Best regards,

-a-