Fuel Leaking From Pump

[Guest Paul S Usowicz]

Hi All

 

At the rear of my Sub-K I have mounted a Facet Red-top fuel pump. This has two Facet 8mm unions screwed into it. These are a tapered thread and, in theory, should seal. However, one of them is still seaping a small amount of petrol. My question is this - can I seal the union with loctite or will the petrol attack it? If not, any other suggestions?

 

Cheers

Paul S Usowicz

[Guest Fred2b]

Paul

You will have to be very carefull whatever you use because just a little bit will clog the pump, however if anything I would use hemmatite red, It's designed to seal gaskets against petrol so it should work.

Regards

Fred

[Longboarder]

You could try PTFE tape. I admit I have no idea if it dissolves in petrol.

 

Nigel

[Guest timswait]

When I bought my plastic fuel tank from Chris Gibbons I found he had sealed the Unions which screw into that with PTFE tape, and I've had no leakage, so it must be petrol proof. Also it's easier to avoid getting bits in the fuel than with a gunge like haematite.

[Guest GeordieJim]

PTFE Tape is proof to virtually all chemicals known to man (which includes petrol).

[Peter Bell]

PTFE Tape is proof to virtually all chemicals

Apart from stuff with high fluorine content! no problems with petrol though!

Peter.

[Longboarder]

Not good for sealing toothpaste tubes then!

 

Nigel

[Guest GeordieJim]

I clarify. PTFE tape is proof to virtually all chemicals known to men who build cars (except for pickling paste).

 

So don't wrap your hands in PTFE paste while using pickling paste - it will cause an awful mess.

 

Heated (or on fire) o-rings also give off hydrofluoric acid as well, so keep away from your car if its on fire (not to mention the explosion risk).

 

Seriously though, if you melt an o-ring don't pick the resulting mess up with your bare hands or it may tickle a bit.

 

James (person who works on a chemical plant).

[Peter Bell]

Jim it is only O rings and seals made from Viton (Fluorocarbon) which have this effect. but they will be used in fuel systems for modern cars running on unleaded fuel.

Peter.

[Guest GeordieJim]

You're correct, but to the untrained eye it won't be easy to tell the difference between Viton, natural rubber, EPDM, or any other type of rubber / fluoropolymer, so I would just play safe.

 

Thinking about it, PTFE tape itself will probably five off some pretty nasty fumes if heated. It tends to go black and carbon like, but the florine content must go somewhere. Investigations required. Something to do at work today methinks.