Can You Identify These Deck Fills?

[Cloroxbottle]

The plastic caps and their gaskets (not standard O rings) are getting old and water is leaking into the diesel.

Unfortunately I have yet to see anything like this. All the replacement caps I have seen are threaded with standard O rings.

Hoping not to have to replace the deck fills themselves, but suspecting I am going to have to.

[s/v Jedi]

What isn’t standard about the O-rings? Inside diameter, outside diameter and thickness it should be possible to find. It took me two tries to get the right ones for my deckfills (original Perko ones were $5 each, now I got the same ones $0.50 each).

[deblen]

My danish built boat is equipped with these. I researched them many yrs ago & found the EU mfgr/brand name,but can't remember it or find a record of it.
As Jedi said-I took a cap to a local machine shop that has an assortment of o-rings & picked one that was same as original & works fine .
These are soft plastic.One of mine had been stripped by overtightening with winch handle-very easy for an inexperienced person to do. Luckily,I found a used one on ebay. I made a new "wrench" for fuel & water by sawing the handle off an old winch crank at 3". / Cheers/Len

[Nicholson58]

Originally Posted by s/v Jedi

What isn’t standard about the O-rings? Inside diameter, outside diameter and thickness it should be possible to find. It took me two tries to get the right ones for my deckfills (original Perko ones were $5 each, now I got the same ones $0.50 each).

So correct Obi-wan.

Our diesel master at Torresen in Muskegon noted that the #1 cause of water in your fuel was leaking, old, cracked O-Rings. They used to change them for free for winter customers.

We$t Marine carries them most places but expensive. ID OD cross section. All O rings can be cross referenced and easily bought on line. Make sure you get a material OK with fuel. Most are Nitrile. Very long life, get Viton.

In the US, Try McMaster or Grainger, or Tractor Supply, or Quality Farm & Fleet. You can also get them at most hydraulic supply houses.

[Cheechako]

Just find the right thickness of oring and stretch a bit to fit. Nitrile is best for Diesel IIRC.

There's a dolphin logo on that fitting... wonder if that ID's it?

[Spot]

Maybe a clear shot of the logo would help someone recognize it.
If you live near a Fastenal store they might have some too.

[GordMay]

Nitrile, also called NBR or Buna-N, nitrile o rings are probably the most economical and widely used. Nitrile is not good at resisting degradation by ozone or weather
The name Viton is a trademarked brand name, and refers to fluorocarbon o rings, or FKM/FPM. Viton is less tolerant of low temperatures.
Viton [FKM/FPM] is superior to nitrile in almost all situations, excluding operation at sub zero temperatures, but both offer excellent compression set, & hydrocarbon compatibility, and have a wide range of uses in industrial and domestic applications.

[s/v Jedi]

Just in case people wonder: I’m pretty sure these are the O-rings that fit my Perko deckfills (I searched my orders and this was the last one of three attempts. I also found I returned the others as “did not fit” under their free returns option

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[marcjsmith]

I have these same fill caps on my moody

easy deck filler caps. found them at force 4 chandlery. could not find them stateside
https://www.force4.co.uk/item/Easy/S...ler-Diesel/HZM
https://www.force4.co.uk/item/Easy/S...eck-Filler/HZO



I ended up buy new caps and gaskets, also ordered a spare set of gaskets. kept the old caps as a spare just in case i lose one overboard.


shipping WILL cost more than what you are buying.

[Nicholson58]

Not that tough. If You don’t feel comfortable measuring then take the fitting to a hydraulic, automotive or tractor supply store and buy one. Note the three digit dash number and cross section. Buy a few on line and store in a ziplock baggy.


https://www.marcorubber.com/o-ring-size-chart-as568.htm

https://www.marcorubber.com/o-ring-size-chart-index.htm

https://www.theoringstore.com/store/...in_page=page_2

https://www.mcmaster.com/o-rings/

[marcjsmith]

Originally Posted by Nicholson58

Not that tough.

its not an o ring, its more a thick gasket... with a flat profile.

[Nicholson58]

It’s an o ring that is permanently squashed and deformed.

[marcjsmith]

Originally Posted by Nicholson58

It’s an o ring that is permanently squashed and deformed.

once again. no its not. is it a flat gasket in the shape of a circle. AKA rubber washer



as I mentioned above I have the same filler caps for my moody and when i ordered new caps and gaskets it was not a squished o ring it is a flat gasket



take a look at the second link I posted. the pics doesn't lie

if you put an o ring in that fits the thickness, it won't engage with the flange on the the filler neck. I went down that road before I spent $$ for the proper size from the manufacturer.

[Nicholson58]

Originally Posted by marcjsmith

once again. no its not. is it a flat gasket in the shape of a circle. AKA rubber washer



as I mentioned above I have the same filler caps for my moody and when i ordered new caps and gaskets it was not a squished o ring it is a flat gasket



take a look at the second link I posted. the pics doesn't lie

if you put an o ring in that fits the thickness, it won't engage with the flange on the the filler neck. I went down that road before I spent $$ for the proper size from the manufacturer.

Are we talking about the same thing? The enhanced photo of the OP appears very much to be an O Ring. I would need to see it removed from the cap to think otherwise.

There are alternate cross section O Rings, X and Square that can be substituted for round. (Follow my links above). They fit in the same spaces but can provide a better seal especially on worn parts. Perhaps yours was such a substitution.

[Cloroxbottle]

They are mostly flat with a raised center section (or worn out inner section). I tried to McGuyer a reasonable substitute with a O ring kit I carry but no luck.