10 replies to this topic

[MateyTheMini]

Hi all!

Just a quick question.

The Rubber ring around the fuel tank float, should I leave it on or take it off?

Thanks,
Callum

[MRA]

Why would you want to remove it Callum ?

It was fitted for a purpose, we know this because Rover (etc) were far too tight to fit something that isn't required....

[MateyTheMini]

I'm not sure, i been told it swells up and just falls off the float or something!

It's my dad whos doing it for me !

Thanks,
Callum

[MRA]

And how long has the one on your float chamber been in place ? I guess it must still be there ? Is it showing signs of degredation ??

[MateyTheMini]

It's not long been fitted, bought it at Bingley Hall! fitted on same day :/

We do still have it, but when you put it on it expands and falls off into the petrol.

Thanks,
Callum

Edited by MateyTheMini, 09 February 2011 - 07:55 PM.

[MRA]

Have yo uinformed the company you bought it from ?

This shouldn't happen, i suspect that the wrong grade of rubber has been used to manufacture the O rings

[MateyTheMini]

Ah. it was at Bingley i can't exactly remember what stand i bought it off, they said it was the correct one so i'm not sure!

Thanks,
Callum

[MRA]

Parts guys are not always or indeed often Engineers, I mean Engineer as in design and development, it is unfortunate that you may have been sold the correct size of O ring "it fits ok" however some polymers react with petrol and the type you need would have to be a non butyl or silicon rubber, you would really need a Viton or similar...

[MateyTheMini]

Ah, this could be the problem then! Paid 22 pound for the whole desender unit and float :/

I don't suppose you sell one at MRA do you?

Thanks,
Callum

Edited by MateyTheMini, 09 February 2011 - 09:02 PM.

[dklawson]

Fuel system rubber parts should be Buna-N (a.k.a. nitrile or NBR) or Viton. Viton is not more resistant to gasoline, but it does offer higher temperature resistance. Butyl rubber is not compatible with gasoline, nor is silicone rubber.

I have seen the float rubber ring swollen on some Smith sending units but not on ones I have removed from Minis. I believe the purpose of the ring is/was to prevent rattling should the float come into contact with the inside walls of the tank. Therefore, you could do without it. There should be no functional change, just a potential rattle at completely full or nearly empty.

[MateyTheMini]

Fuel system rubber parts should be Buna-N (a.k.a. nitrile or NBR) or Viton. Viton is not more resistant to gasoline, but it does offer higher temperature resistance. I butyl rubber is not compatible with gasoline, nor is silicone rubber.

I have seen the float rubber ring swollen on some Smith sending units but not on ones I have removed from Minis. I believe the purpose of the ring is/was to prevent rattling should the float come into contact with the inside walls of the tank. Therefore, you could do without it. There should be no functional change, just a potential rattle at completely full or nearly empty.

Ah! Thank you, i'll let him know later.. I think he was planning on taking it off as it just keeps dropping off, big help from you and MRA

Cheers,
Callum