Fuel Fill O-Rings

[captainmaniac]

Seeing the post re seacock o-rings, I decided to start this thread instead of hijacking...

My '79 F32 has (I think) original fuel fill deck plates. I think the o-rings are probably shot, as tightening the cover on one fill leaves it 'proud' of the base by about 1/8", and tightening the one on the other side I am sure I am getting metal on metal before the o-ring can seal...

So... looking for where to get replacement o-rings for the fuel fills.

I have looked on the Beacon site but never seen o-rings listed. I have tried to take measurements but am afraid that I could destroy the rings by trying to pull them out (they are 35 years old after all)... so best I can measure them without removal it appears that they are 2" ID, 2.25" OD. Have any of you replaced these? What is the right replacement part/size? I don't know if the fuel fill o-rings need to be fuel rated, or just water rated? Their job is to keep water out, but they may get some fuel splashed on them during filling...

If I am going to replace the fuel o-rings, I may as well replace the one for the fresh water tank as well. My rough measurements for it were 1 15/16" ID, 2 3/16OD .... again, can anyone else confirm these numbers or have you done this before?

[Paul]

I replaced mine by measuring the diameter on the center line as well as the thickness diameter followed by a quick trip to the local hydraulic supply shop. I picked up some Buna-n "O" rings that were a perfect replacement.

Hope this helps.

[P-Dogg]

O-rings are sized by I.D. and cross section. Sounds like you have 2 x 0.125 rings. I picked mine up from mcmaster.com.

[ready123]

Water cap should be same size... Remove it and take o ring off then you can measure dia of the seat to get id. The thickness you can usually get from old ring if not look at the seating area in the tube on the boat to get the OD and thus derive the thickness.

[AndyF32]

Does anyone know what the correct size is? I seem to have a mix of o ring sizes on my boat.
Thanks

[ready123]

Easy to measure your own..... Remove cap and take o ring off.
Then measure diameter of base of groove using caliper, look at the inlet coupling it has an obvious groove for where the o ring will contact and measure that o/d... Now you have OD and ID of the O ring to select the one from standard O ring list.

[rbcool]

Lets make this easy....... take your water fill cap down to your local Napa..... have them bring out their tray with all of the O-rings, find the one that fits!!!
I did this last year and bought 6, 2 each for gas-water-pumpout
RB

[AndyF32]

Well I finally got around to figuring out what O rings I needed.

I ordered several sizes and this is what I found out.

1/8" x 2" ID - this size was on my boat but I found they favored the outside of the groove and did not fill the groove

1/8" x 1 7/8" ID - This favored the inside of the groove and again did not fill the groove

3/16" x 1 7/8" ID - This fully filled the groove and when tightened the fuel cap sits a bit above flush. I went with these as it allows me to be sure I have full contact with the O ring. I also use a bit of grease on the O rings. Water in the tanks is no fun.

[RWS]

I have replaced mine three times over 15 years of ownership.

Prob should do more often !

I also use a smear of Vaseline (petroleum jelly)



RWS

[CSlaughter]

On this topic. I have an 81 F36 with what I think are the original (fuel) filler caps. One was seized and required I drill a large hole in the center of it so that I could use a large ease-out to remove it and now I am searching for a replacement. I have tried several off the aftermarket filler caps and all were to small. Any idea where I can get one of the original ones again?

Carl

[Allen Sr]

Did you try Bob at Beacon Marine the sponsor of this sight?

[P-Dogg]

the original (fuel) filler caps

Ummm, any chance one is the water fill????

[CSlaughter]

Did you try Bob at Beacon Marine the sponsor of this sight?

I had looked in the past to see if he had any listed, but did not see any.
I will give him a ring and see if he has any inventory that is not listed on the website.

[Allen Sr]

Did you try Bob at Beacon Marine the sponsor of this sight?

I had looked in the past to see if he had any listed, but did not see any.
I will give him a ring and see if he has any inventory that is not listed on the website.

He has lots, of inventory that's not listed on the website