Fuel cap O-ring Replacement

[mike_elliott]

The large O-ring 338 in fluorosilicone is available on Amazon for about $10.5 includes shipping (prime) here: http://www.amazon.com/gp/product/B0055E1RLM/ref=ox_ya_os_product 

 

The little one, size 010 in fluorosilicone is also for sale . . . in packages of 100! I bought that, so have so many little blue O-rings I'll never use them all. If you want two little blue O-rings for free, send a stamped, self-addressed envelope to:

 

bumper (O-ring offer)

194 Taylor Creek Rd.

Gardnerville, NV 89460

 

Limited to stock on hand, all entries remain the property of Bumper LLC, decision of judges are final, we reserve the right to refuse service to anyone (or eveyone, for that matter), if you like your O-ring you can keep your O-ring.

Thanks bumber! SASE sent! Your the man! 

[Guest]

It is a simple as it looks. One of the $mall things that some shops use to pad an annual bill. http://mooney.free.fr/Mooney%20SB%20SI/229A.pdf The service bulletin is to CHECK the o rings annually not replace every year. Plus it is a SB not an AD. If your o rings get replaced at every annual you ARE getting ripped off.

I'm trying to get this right, I remove and disassemble the fuel caps on a customers plane and inspect the "O" rings. If I replace them, especially the small inner one I'm ripping my customer off.

If they are not worn I re assemble and adjust the cap and reinstall it. By not replacing the inner "O" I've saved the customer about 50 cents per cap. I'm pretty sure this would be view as a waste of effort if not a rip off.

Clarence

[flyingvee201]

SASE from me too!!

Thank you!!

[scottfromiowa]

Congrats...you guys wiped Amazon out of stock...

[bumper]

SASE from me too!!

Thank you!!

You're all welcome. For awhile there I thought I might have to make a small rubber band gun for #10 O-rings.

 

Keep in mind that Fluorosilicone, like the stock Buna-N O-rings, are compatible with gasoline and most other petroleum products. Unlike Buna-N, Fluorosilicone is very resistant to UV and ozone weathering. But, Fluorosilicone is not very abrasion resistant. So I think it a good idea to lubricate them, especially the ones you get from me for the shaft, with grease. Either silicone grease* (Dow-DC4 or similar) of a petroleum grease will do. If you use silicone grease, you can also wipe it on the large outside O-ring too as that will help prevent abrasion wear.

 

*You *need* some silicone grease anyway, it's great stuff to weatherproof coaxial connections, electrical connections, spark plug connectors, and lubricate O-rings of all sorts including water filters as most silicone grease is food safe (but NOT for use on plain silicone O-rings). This is a lifetime supply for most - - get some small containers and share with neighbor and family: http://www.amazon.com/gp/product/B009CFNL46/ref=oh_details_o03_s00_i00?ie=UTF8&psc=1

 

bumper

[Hank]

I squirt Tri-Flow down the center once or twice a year now. Will this work with the fluorosilicone o-rings too?

[Awqward]

The oil from the dipstick worked perfectly for me yesterday! The line-guy was struggling to that point....the simple solutions are often the best..,

[RJBrown]

I'm trying to get this right, I remove and disassemble the fuel caps on a customers plane and inspect the "O" rings. If I replace them, especially the small inner one I'm ripping my customer off.

If they are not worn I re assemble and adjust the cap and reinstall it. By not replacing the inner "O" I've saved the customer about 50 cents per cap. I'm pretty sure this would be view as a waste of effort if not a rip off.

Clarence

 Why would you automatically disassemble a cap you changed o rings on last year and it is obvious the outer ring looks brand new? Busy work just to pad the bill. On any airplane these o rings last a lot longer than 1 year but some mechanic knowing they were replaced at the last annual will take apart the same cap he took apart before just because a service bullitin gives him carte blanche.

 This is why an inspection should be done and a list of corrective actions be made and then presented to the owner. Nothing beyond the inspection should be done without further authorization. Too many mechanics take it upon them selves to make repairs without authorization. Some like you even think they are doing someone a service by "over repairing" anything they can get their mits on.

 

Replacing them when apart is not the problem. Unnecessarily disassembling them is. If you honestly believe that you MUST take it apart every year you have deluded yourself. Use a little common sense. How many have you replaced? How many were truly bad? In fact if you change them every year you have probably never seen a bad one. 

 

[larryb]

Given the high cost of an off airport landing due to water in the fuel, I am ok with my shop changing the inner and outer o-rings each year.

Sent from my iPad using Tapatalk

[Guest]

RJ,

I'm still confused. Just how would one inspect the small inner "O" with out disassembling the cap? As I don't have X ray vision I know of no other method, perhaps you have a better solution.

The small inner "O" ring is the one with the smallest cross section, and least surface to wear out. It is one which wears with every opening and closing of the cap because its in contact with a frequently rusty and pitted shaft.

In my experience as a maintainer it is the small inner one which will leak when the fuel tank is pressurized through the vent as called out in the service bulletin.

Regards,

Clarence

[scottfromiowa]

Wow, $12 bucks for four gaskets and ten minutes labor to change them...i guess it is 1/2 an AOPA membership so...

Whatever. I will happily continue to have these changed on an annual basis. Maybe in 2015 I will remember to buy them from Spruce and throw away a 1/4 of an AOPA membership...The horror,

The Horror

[scottfromiowa]

Why would you automatically disassemble a cap you changed o rings on last year and it is obvious the outer ring looks brand new? Busy work just to pad the bill. On any airplane these o rings last a lot longer than 1 year but some mechanic knowing they were replaced at the last annual will take apart the same cap he took apart before just because a service bullitin gives him carte blanche.

 This is why an inspection should be done and a list of corrective actions be made and then presented to the owner. Nothing beyond the inspection should be done without further authorization. Too many mechanics take it upon them selves to make repairs without authorization. Some like you even think they are doing someone a service by "over repairing" anything they can get their mits on.

 

Replacing them when apart is not the problem. Unnecessarily disassembling them is. If you honestly believe that you MUST take it apart every year you have deluded yourself. Use a little common sense. How many have you replaced? How many were truly bad? In fact if you change them every year you have probably never seen a bad one.

Is it "delusional" to not ever want to see a "bad one"? That's the friggin' point of changing them.

[FlyWalt]

It is a simple as it looks. One of the $mall things that some shops use to pad an annual bill. http://mooney.free.fr/Mooney%20SB%20SI/229A.pdf The service bulletin is to CHECK the o rings annually not replace every year. Plus it is a SB not an AD. If your o rings get replaced at every annual you ARE getting ripped off.

 

I just checked my annual bill from last year. The shop replaced the o rings and charged me for an hour of labor. Now I am torqued.

[jetdriven]

75$ to inspect 4 o-rings? It takes longer to remove and replace an inspection panel. Do they charge an hour for each of those too?

That reminds me of the annual on a friends Cardinal RG a few years ago. One of the items was a .8 hour labor charge to replace the dipstick o-ring on his lycoming engine. This was additional to the 3 hours charged to change the oil. They told him each line item was minimum of .8 hours. His annual was ten grand and they didn't repair anything except a carefully hidden scab patch where they ran a jack through the wing.

That same shop later banged our airplane's previous owners for 1100$ to r&r and time a bendix dual magneto.

[Hank]

Wow, ya'll get itemized bills for your annuals? I get a nice sticker that covers an entire page in the logbook, but my bill is often just one or two lines and a total cost. The wonders of small town America and a good relationship with the A&P/IA who works with me on owner-assisted annuals where I do as much as we are both comfortable with me doing, which seems to be more every time she goes in the shop.

[FlyWalt]

75$ to inspect 4 o-rings? It takes longer to remove and replace an inspection panel. Do they charge an hour for each of those too?

 

No they charge $69 an hour to replace them. I need to look more closely and see if I got dinged for the parts too.

[Guest]

If you did not get "dinged" for the parts everyone should be going to your shop. Free parts for all just pay the labour!

Clarence

[chrisk]

Maybe this is a silly question, but do O-rings need to be TSO'd?   And how would you tell if they were or were not?

[Marauder]

Maybe this is a silly question, but do O-rings need to be TSO'd? And how would you tell if they were or were not?

Just be glad you don't have the caps for the bladder system. Those o rings are $50 each...

Not sent from my underpriced Nexus 7 using Tapatalk

[scottfromiowa]

O-rings come in a paper sealed bag with part number on them.

[chrisk]

O-rings come in a paper sealed bag with part number on them.

Maybe I should be more specific.  The SB mentions parts MS29513-010 and MS29513-338.  The amazon oring doesn't have this number.  And the McFarlane oring has a PMA number, but it doesn't reference the Mooney part number. 

 

What I am asking is:  Does a mechanic need to use the Mooney part number o-ring, or is it in the mechanics discretion to use any appropriate o-ring?

[jetdriven]

The MS series is a common nitrile rubber o-ring. If your mechanic is cool with substitution of parts for improved ones, you can install the blue ones and be done with cracking o-rings. The blue ones are standard on the bladder style fuel caps. They come from King Airs, learjets, and Citations.

[bumper]

I squirt Tri-Flow down the center once or twice a year now. Will this work with the fluorosilicone o-rings too?

 

Sure, no problem. You can use petroleum, synthetic, or silicone lubricant with the 'blue" fluorosilicone O-rings.

[jwilkins]

I'm trying to get this right, I remove and disassemble the fuel caps on a customers plane and inspect the "O" rings. If I replace them, especially the small inner one I'm ripping my customer off.

If they are not worn I re assemble and adjust the cap and reinstall it. By not replacing the inner "O" I've saved the customer about 50 cents per cap. I'm pretty sure this would be view as a waste of effort if not a rip off.

Clarence

When I had my 62 C I used to have to 'remind' the A&P to replace the O-Rings every annual.

The mechanic who took care of my 67F always asked if I wanted them changed (answer was always yes)

The shop that takes care of my 80 K strongly recommends all four caps get new rings every year, and I absolutely agree with them.

 

It's not a 'rip off' to me to have a mechanic who is watching out for things like this - especially the ones that don't cost much and potentially prevent a huge problem, I expect them to go ahead and do them.

 

I always thank the shop and the mechanic for being professional enough to know what things we SHOULD be doing.  Not all of us owners think we are being 'ripped off' when our mechanics are watching out for us.

 

Personally, I wish ALL mechanics took the time and effort to be thorough and professional enough to take care of things like this. Much better than the possible alternative.

 

I guess the lesson is to try not to be offended by statements made by some people. 

[Guest]

I'm not personally offended, I'm just seeking clarification on what constitutes a rip off.

Clarence