SHAW 431-9 FUEL CAP CONUNDRUM

[OSUAV8TER]

Here are some helpful links toward maintaining your Shaw 431 fuel caps.

First, I supply the full fluorosilicone fuel cap kit. It includes the big o-ring, little o-ring, and cotter pin to outfit one Shaw 431 (or 531) fuel cap.

Second, the Marsh washer kits are worth it. They stop the metal on metal wear of the plunger handle on the metal washer that is in the fuel cap. These caps are over $2500 new from Textron last time I checked and you can't get new parts for them. They also make it much easier to open and close the fuel cap because they have a self lubricating property as the material wears into the plunger handle.

Third, attached is a nice article from the American Bonanza Society magazine about taking care of the fuel caps.

James

ABS May 2017 Article.pdf

[Hank]

I hit mine with Tru Flow every now and again. Keeps them from getting difficult to move, and weeps down into the o-ring a bit, too. Blue fluorosilicone lasts longer, but a bit of lube won't hurt them. 

[Grant_Waite]

The Mooney service manual says to use tri flow whenever they start to get tough. But the ultimate fix is to just replace the caps with something much better. I have bladders and Griggs uses these caps on all there new installs. I previously had the awful Shaw ones. I don’t see why it couldn’t be used on normal mooneys. I know the Griggs hole pattern is different so they special order them from Newton. https://fuelsafe.com/collections/motorsports-refueling-fuel-caps

[OSUAV8TER]

12 hours ago, Grant_Waite said:

The Mooney service manual says to use tri flow whenever they start to get tough. But the ultimate fix is to just replace the caps with something much better. I have bladders and Griggs uses these caps on all there new installs. I previously had the awful Shaw ones. I don’t see why it couldn’t be used on normal mooneys. I know the Griggs hole pattern is different so they special order them from Newton. https://fuelsafe.com/collections/motorsports-refueling-fuel-caps

The Shaw caps are excellent if they are maintained. One issue I see for you is that in the future if you need to maintain/replace/repair those fuel caps, who has the parts? One small business?

Shaw fuel caps are everything. They are not only on Mooney aircraft but found on Bonanzas, Barons, baby Beech aircraft (Sierra, Skipper, Sundowner, etc.), Aerostars, Kingairs, Citations... I have seen them on drop tanks for F-16s. 

I can get parts for them readily if needed.

[Grant_Waite]

3 hours ago, OSUAV8TER said:

The Shaw caps are excellent if they are maintained. One issue I see for you is that in the future if you need to maintain/replace/repair those fuel caps, who has the parts? One small business?

Shaw fuel caps are everything. They are not only on Mooney aircraft but found on Bonanzas, Barons, baby Beech aircraft (Sierra, Skipper, Sundowner, etc.), Aerostars, Kingairs, Citations... I have seen them on drop tanks for F-16s. 

I can get parts for them readily if needed.

If you have bladders in your Mooney these caps are a no brainer. Lockable, no silly metal washer that needs to be replaced with a 100 dollar plastic one and super easy to get on and off. There is replacement parts available from AS for 20bucks. If I accidentally lose a cap, I can buy an entirely new cap for less than 200 bucks. So they’re readily available and are cheap. Best of all I can buy them new and not used. They’re the same brand of cap diamonds use and a lot of experimentals use. Be my guest to overpay for an outdated design and a company who could care less about GA. But I wasn’t supporting that nonsense anymore. At least when I google Newton a company actually shows up  

https://fuelsafe.com/products/a4l

[OSUAV8TER]

2 hours ago, Grant_Waite said:

If you have bladders in your Mooney these caps are a no brainer. Lockable, no silly metal washer that needs to be replaced with a 100 dollar plastic one and super easy to get on and off. There is replacement parts available from AS for 20bucks. If I accidentally lose a cap, I can buy an entirely new cap for less than 200 bucks. So they’re readily available and are cheap. Best of all I can buy them new and not used. They’re the same brand of cap diamonds use and a lot of experimentals use. Be my guest to overpay for an outdated design and a company who could care less about GA. But I wasn’t supporting that nonsense anymore. At least when I google Newton a company actually shows up  

https://fuelsafe.com/products/a4l

How much did it cost for the STC to modify your aircraft to install that fuel cap along with the receptacle to take that cap? 

[Grant_Waite]

 

3 hours ago, OSUAV8TER said:

How much did it cost for the STC to modify your aircraft to install that fuel cap along with the receptacle to take that cap? 

There was no stc or anything I had to pay for. I called up Griggs she said they were waiting on the caps to be made. Fast forward a month later I got the caps and paid 432 with shipping. Even if you could find the cap that was on my plane you couldn’t get one for that price. Mine weren’t the ones used on everything else. Griggs had used a specific version that Shaw supplied only to them and who else I don’t know. But you can’t find my caps no matter how hard you try. And I know 432 is less than any new Shaw cap on the market so I’m perfectly tickled pink by it. Like I said if your Mooney has bladders this is a no brainer upgrade. I paid at least over 200 bucks for all new seals and the plastic washers on my old shaws. Because of course the blue seal on mine was different than every other Shaw cap. 
 

Edited September 13, 2024 by Grant_Waite

[OSUAV8TER]

From a certification standpoint, going on certified aircraft, is there a PMA, anything on these parts? It might be a more cost effective technically superior solution but without a certification pathway, doing this is going to be a challenge.

[DCarlton]

I'll have three Shaw caps with Flurosilicone O-rings and Marsh washers for sale early next year.  Expect to receive bladders around the first of the year.  

[Grant_Waite]

Griggs told me this is what they use and said I could use them… so that’s good enough for me. If they asked anyone or modified the stc, I don’t really know or care. They are great people and one of the few places you can trust these days. Unpopular opinion but I think a lot of the FAA rules on parts are egregious. Not trying to start an argument but that’s my opinion. Everyone will do things to their plane that some would appall at. Such as changing all the interior incandescent bulbs to leds. Or using the led non pma bulbs in grimes nav light etc. 

Edited September 13, 2024 by Grant_Waite

[EricJ]

29 minutes ago, Grant_Waite said:

Unpopular opinion but I think a lot of the FAA rules on parts are egregious. Not trying to start an argument but that’s my opinion. Everyone will do things to their plane that some would appall at. Such as changing all the interior incandescent bulbs to leds. Or using the led non pma bulbs in grimes nav light etc. 

Another unpopular opinion:   The FAA rules aren't really that egregious, but how some people insist on interpreting them can definitely be egregious.   Note that the VARMA program exists in order to provide owners documentation from the FAA that a part is okay to be on their aircraft so that the next IA won't make them take it out.

[DCarlton]

23 minutes ago, EricJ said:

Another unpopular opinion:   The FAA rules aren't really that egregious, but how some people insist on interpreting them can definitely be egregious.   Note that the VARMA program exists in order to provide owners documentation from the FAA that a part is okay to be on their aircraft so that the next IA won't make them take it out.

Uh oh.  Now I've gotta go read about this thing called "VARMA".  

[OSUAV8TER]

The problem with this solution is that there are no FAA approvals. You do what you want to your airplane in my opinion but when you go to sell it, it will likely become an issue when an IA sees an unapproved part on the aircraft and it has to come off or not. It's risky so it's not a great fleet-wide solution. Get it approved and it is a different story.

[EricJ]

51 minutes ago, DCarlton said:

Uh oh.  Now I've gotta go read about this thing called "VARMA".  

I tried to find it, but somewhere on faasafety.gov or somewhere else, Scott Fohrman of the FAA Chicago Air Certification branch has given several webinars on VARMA.   He's one of the guys that helped create it, and I think the more recent presentations may be better, but I couldn't find an archive copy.    If you are an EAA member they have a copy of the webinar from August of last year here:

https://www.eaa.org/videos/vintage-aircraft

If you get the webinar/seminar notices from faasafety.gov, keep an eye out for any potential upcoming events on the subject and you can get the latest.

VARMA is Vintage Aircraft Replacement and Modification Article.   It doesn't leverage any new regulations, all of the previous regs and ACs for vintage aircraft parts substitution apply, but the VARMA program established a process by which you could formally apply for a "VARMA letter" from the FAA which documents the approval of a part for the installation on an individual aircraft.   That FAA document then serves as the "approval" for that part to be on the aircraft so that it can be shown to maintenance personnel and inspectors.   It is not outside of any normal process, no new regulations or permissions are necessary, the only purpose of the letter is to provide a formal documentation that the part is compliant with existing regs and can be installed on the aircraft.   A number of examples were given in the event that I attended, including installing a starter solenoid from NAPA on a C150, stuff like that.

Note that a VARMA letter is not required to install any part, it only serves as formal documentation of approval of the installation if the owner desires it so that future IAs won't make them take it out.   It was amusing to me to hear them describe this as an IA education program, and that if ultimately successful the program would put itself out of business once IAs stopped removing allowed parts.

[Grant_Waite]

I suppose I’m based as I’m currently dealing with exactly what @EricJ said. Mooney is of no help as they said they wouldn’t give me any technical data or drawings without permission of an Mooney engineer. I’m doubtful Mooney has a need for an engineer, so pretty sure they don’t have one anymore. Now I’m left in a scenario where I’ve been aog for 3 months and had to find a solution to get it airworthy so I can fly it to another shop that’s confident in their work. These are all Mooney certified parts and modifications Mooney sold back in the day, that I’m trying to do. Not trying to do anything wild mind you. But each IA interpretation is different and some are enslaved by fear of the FAA for everything. 

[highflyer77]

Dear Mooniacs, I just found this thread as I am dealing with the same fuel cap issues on one of my fuel cap´s (the lever is not closing down fully anymore, when I close it. It still works, but I certainly don´t want to see it popping off in flight, or have water in my tank due to a open fuel cap, because it popped open...). The fuel caps on my aircraft (M20E) are shaw 431-9. I am offered a used cap type 531-1. Will it fit and am I allowed to use it on my aircraft ? Thanks to all of you in advance !

[KSMooniac]

6 minutes ago, highflyer77 said:

Dear Mooniacs, I just found this thread as I am dealing with the same fuel cap issues on one of my fuel cap´s (the lever is not closing down fully anymore, when I close it. It still works, but I certainly don´t want to see it popping off in flight, or have water in my tank due to a open fuel cap, because it popped open...). The fuel caps on my aircraft (M20E) are shaw 431-9. I am offered a used cap type 531-1. Will it fit and am I allowed to use it on my aircraft ? Thanks to all of you in advance !

I don't think they're interchangeable.  You might contact @OSUAV8TERand see if he can help you fix what you have.

[Ragsf15e]

33 minutes ago, highflyer77 said:

Dear Mooniacs, I just found this thread as I am dealing with the same fuel cap issues on one of my fuel cap´s (the lever is not closing down fully anymore, when I close it. It still works, but I certainly don´t want to see it popping off in flight, or have water in my tank due to a open fuel cap, because it popped open...). The fuel caps on my aircraft (M20E) are shaw 431-9. I am offered a used cap type 531-1. Will it fit and am I allowed to use it on my aircraft ? Thanks to all of you in advance !

Did you (or your mechanic) take it apart and see what’s wrong? They are dead simple to maintain, especially with new o rings available. I don’t think I’d give up on one too easily.