Fuel sender

[Penfold]

For a while now I've noticed that fuel gauge never quite makes it to the full position even when the tank is filled right up to the neck of the filler tube. I've read various posts and have checked the gauge by earthing the sender feed - which shows all is well as the gauge goes to full. I have a feeling the float on the sender may no longer be watertight which is causing the lower-than-actual reading at the gauge. Before I replace the sender I have a couple of questions:

 

- I read on one of the many posts that you can release the filler tube and hinge the fuel tank forwards just enough to get the sender out without having to drain and completely remove the tank and pipe fixings. I assume this is simply a case of removing the top bolts on the tank and loosening the bottom ones to allow it to slip forward - am I right? (I really don't want to cause any damage to anything - especially any pipe fixings - so it would be good to know if there are any tricks to this I need to be aware of).

 

- The previous owner went a bit mad with sealant around the sender gasket - I assume to make damn sure no fuel leaked. Is this really necessary or should the gasket do its job assuming it's screwed nice and tight? Any tips or clues most appreciated.

 

Thanks all,

 

David

[boxofbits]

Hi David

 

Sounds like the circuit within the Sender Unit may have a dead spot at the top of the range. It might pay you to run the tank right down, drain any residual fuel by undoing the tank fuel line, and removing the tank so that you can properly clean up around the sender unit aperture. It may be worth asking on here who is the best supplier for a new unit to avoid any repros which don't read accurately.

 

I certainly wouldn't use sealant on the gasket, as if some of it gets into the tank you might open a can of worms with small pieces of sealant in your pump and fuel lines. The gasket properly seated should be fine.

 

Regards

 

Kevin

Edited May 2, 2016 by boxofbits

[rog1]

Hi,

 

I do recall having a broken coil wire on a triumph sender (back in the late 80's) and I just rewound what was left after the break in the coil winding. That just made it shorter and therefore altered the resistance which resulted in an incorrect reading on the gauge. It's possible that may have happened to yours?

 

As for removing it with the tank still in position, I can't help there, I recently removed my tank and tested that the sender was working first, as I didn't think it would be easy to replace afterwards with the tank in place. Maybe someone will reply and advise otherwise.

 

Regards

Roger

[Penfold]

Thanks for your responses. Does anyone have any experience with changing the fuel sender without removing the whole fuel tank - just tipping it forwards a little? Would be very interested in any tips. Thanks all.

 

David

[JustinF]

Hi David

I have recently done just this as the fuel sender was not working on my TR6.

I would suggest you run the tank as low as you can of fuel as it makes it much lighter to handle.

Before disconnecting to much just take the wires of the old fuel sender unit and connect them to the new sender unit and with the ignition on test it to make sure you are getting the readings you would expect on the fuel gauge, as you don't want to take everything apart only to find this is not the problem.

Then remove the wires from the sender unit, disconnect the return pipe from the top of the tank (I didn't and ended up kinking the return pipe). Then disconnect the fuel filler pipe and fuel cap.

Then remove the tank retaining bolts and tip the top of the tank towards you to access the fuel sender unit, keeping an eye on the pipes to the pump and filter to make sure you are not twisting or damaging them.

 

Make sure you have a new cork gasket to hand as you don't want to get stuck for something that only costs a few pence.

It is much easier if you have an assistant as they can hold the tank whilst you remove and fit the new sender unit, although it is still possible to do it on your own as I did just not quite so easy.

Once the new sender is fitted just bolt everything back in place.

I would recommend getting some red brake and rubber grease to smear on the inside of the fuel filler rubber pipe to make it easier to re-fit and also put a bit on the fuel filler cap tube when refitting it as I was struggling to re-fit mine before doing this.

Make sure everything is re-connected then start the car to test everything works as it should and you have no leaks, then go for a test run and fill up with fuel to make sure the gauge now works as it should and also that you don't have any leaks around the fuel sender. Best to leave out the trim panel until you know this is all ok, BUT MAKE SURE YOU TAPE UP THE WIRES TO THE BOOT LIGHT, as you don't want to create any sparks near the fuel tank.

Good luck let us know how you get on.

 

Justin

[Penfold]

Justin - you're a star! Thanks for putting me in the picture. It's always encouraging when you find someone who's already done what you're trying to do....just a couple more questions:

 

- I'm assuming you can disconnect the return pipe from the boot side of the tank and don't need to go in from the luggage compartment (behind the seats)...?

- Did you get your replacement sender from Rimmers or somewhere else? (Just need to make sure the one I buy isn't worse than the original!)

 

Thanks again,

 

David

[JustinF]

David

I unscrewed the metal part of the return pipe from the top of the tank from inside the boot, no need to go into the luggage compartment behind the seats.

I got my new sender, cork gasket and retaining screws from the TR Shop Chiswick.

I bought the screws just in case the originals were not good enough to re-use but they were ok.

Hope this all helps.

 

Justin

 

PS forgot to say I just used a light smear of ordinary grease on each side of the new cork gasket.

Edited May 4, 2016 by JustinF

[Penfold]

Thanks! I'll give it a go. Just need to drive around some more to empty the tank. It's a hard life! Thanks again.