Sealing 6AN adaptor onto fuel filter

[xb-60]

I'm certain I'm on the right track here, but there's a small chance I'm missing something.

Here's a picture of my Bosch fuel filter...



The thread on the adaptor is a parallel thread, and a steel washer is supplied. Surely there is no way this joint will be fluid (petrol!) tight?

I will ditch the washer and source an O-ring to use in its place.

Any alternate opinions?


Cheers,
Glen

[1795]

Glen,

There are thread sealants that are petrol impervious that you can use as well.

Jim

[Grubby]

If the washers are "soft" steel then it will seal. Brake calipers use a similar method.

I would probably use a thread sealer to be sure and use the washers that came with it.

John

[spdbrake]

You're correct on the o-ring in the the AN815 union. A Buna (aka Nitrile) works best on Gasoline or Ethanol mix.
https://www.efunda.com/designstandar...one&SC=Ethanol

There are several companies the sell AN to ORB (o-ring boss) fittings that also include the oring with it.
https://vibrantperformance.com/catal...e75f2975267d6f
https://www.highflowfuel.com/c-12084...-male-orb.html

[xb-60]

Thanks for the comments, friends!
I am going with the Nitrile O-rings. I don't want to have to re-address this later

Cheers,
Glen

[CJ428CJ]

It looks to me like you don't have the right type of fittings. Are you sure the fittings on the Bosch filter aren't NPT? I suspect you need AN on one end and NPT on the other. That's not what you have now.

Chris

[xb-60]

It's a 6AN thread on one end of the adaptor, and M14x1.5 (definitely not a tapered NPT thread) on the other end.
The thread on the Bosch filter is a matching female parallel M14x1.5 thread.
Hence my concern that the adaptors won't seal without (Nitrile) O-rings.

The two adaptors (ie one for each end of the filter) are identical, and the threads on both ends of the filter are identical.

[Gaz64]

Glen,

Can you show a photo of the fitting screwed right in, to where the washer should function like any other type of sealing washer, like a sump plug?

If you can get an "ORB" fitting, then an O-ring of the right section could be used. I have done this on regulators etc.

Gary

[xb-60]

Hi Gary,

Are you saying that the steel washer would/could seal adequately?




Cheers,
Glen

[Gaz64]

I would use an aluminium or soft copper washer.

[xb-60]

Does the adaptor that I'm using (see pic.) look like an ORB fitting? I'm not familiar with them; I've only ever used or specified (professionally) O-rings with correctly designed and toleranced O-ring grooves.

[Gaz64]

I would say that fitting is meant for a flat washer.
The taper just below the hex helps to self centre the washer.
An ORB fitting doesn't have that taper, which gives the gap for an O-ring to fill into.
You could machine that taper out, then select a Viton or Buna O-ring of the correct section thickness.

[Morris]

Use https://www.pegasusautoracing.com/pr...yABEgKkRvD_BwE

These are the best way to seal a fuel filter

[Gaz64]

Originally Posted by Morris

Use https://www.pegasusautoracing.com/pr...yABEgKkRvD_BwE

These are the best way to seal a fuel filter

Yes, another option. Thanks Morris.

[xb-60]

Thanks Morris. I'll use the Stat-o-Seal washers as a backup if the following doesn't work.

I've fitted Cu crush washers both ends of the filter; added fuel for a static test on both ends and it's looking good.



Thanks all for suggestions.

Cheers,
Glen