O Ring for CTLS fuel cap

[Al Downs]

Does anybody know the size of this o ring? Can't find it in the manual and I have one that is missing keeping me grounded. I do have a local source for Viton Orings but no way to measure the size.

[FlyingMonkey]

Does anybody know the size of this o ring? Can't find it in the manual and I have one that is missing keeping me grounded. I do have a local source for Viton Orings but no way to measure the size.

 

I have a bunch of the viton o-rings for the CTSW.  If somebody can confirm the CTLS uses the same ones, you can PM me your address and I'll send you two.

[Al Downs]

I have a part number for what I believe is for the SW. OV-75-222 is the part number I tried. I was able to get that but it is less than half the size I need. That is why I think it is for the SW. Aircraft Spruce has what I need according to Flight Design. Part # 50-02611 but I was hoping to find the size so I can get it locally today.

 

Thanks

[Anticept]

Hi aldowns!

 

To measure o-rings, use a caliper. You need to have an o-ring chart to consult with, but typically you will measure the inside diameter and the cross section. Some charts use inside and outside diameter instead of cross section. The important thing about measurements, is you do not put stress on the o-ring while measuring. You should put just enough force on the ring to see the caliper forks make contact, but not deform the o-ring.

 

I have attached an o-ring chart. Make sure you read the titles for each section!

 

 

o-rings.pdf

[Al Downs]

I did compare some orings but I believe these are metric and my source doesn't have a way to measure metric. He can get metric Viton orings but he needs to know the size.

[CT_MATT]

Al,

 

Awhile back I tried to find some "off the shelf" orings for my LS caps and it was tricky and I ended up buying from Aircraft Spruce.  The problem is the size.  I found that the large one is 3mmX57mm and the small one is 2mmX6mm.  As Anticept has stated, the cross section is the first number and the ID is the second.  I tried several non-metric orings (we have a ton to choose from here at work) with no luck.  The cross section was not quite right (and stretching a smaller one didnt give good results since you can only stretch so far...) and the fit needs to be just right or it will leak.  The smaller oring is even worse since orings in that size are not common so your choices are few.  Doubtful it is the small oring but, you never know.  Hopefully this helps some...

[gisurvey]

Hello,

 

CT_MATT is right.

O-rings for SPRL 65mm fuel cap (CTLS) are 57x3 and 6x2, metric, Viton.

 

Is there are signs of fuel leaking, also check the epoxy used for fuel cap socket fastening in place.

 

Regards,

Alec

[Al Downs]

Thanks for all the help. I was able to order them today and pick them up in the morning. I will let you know if they are correct.

 

I was able to find a neoprene one today that works but I want it to be the correct one. Never did figure out how the old one went missing.

[Anticept]

They dry up from exposure and tend to get lose. It might be floating in your fuel tank. The wing roots have large screens to prevent anything like that from getting caught in the fuel line though.

[Al Downs]

well it took a couple of days to get them but my local bearing shop was able to order them in for me. I don't know if the part numbers will help others but here they are.

 

Large one is N3.00x057                   size  57mm id  x 3mm C. S.

Small one is N2.00x006                    size 6mm id   x 2mm C.S.

 

I got 4 of each so I have spares.

They were so cheap he didn't even charge me.