Triumphrat

InParkSlope · 10-03-2005

I removed the tank to look into my tank vacuum issue. Don't do what I did and think that that rear tank bolt is a hinge. It is a hinge for a few inches, then it acts like a lever on the metal bracket, and bends it.

Luckily, it can be bent back. But that is a PITA.

Triumph at the factory also torqued the plastic trim bolt on one side so much that it dug into the plastic, revealing white

Under the tank is four fittings. Fuel (doh), electrical (so your tank can explode like an airplane over long island), and two little nozzles that join two little hoses. One hose has a plastic fitment a few inches down, and goes "somewhere", the other one goes straight to the ground.

I didn't find any crimps that would explain the sucking sound at every gas station.

But i also didn't see, (before it was too late), which of the two identical hose tops went onto which of the two identical and unmarked nozzles!

Does it matter? what does the longer hose that goes somewhere actually do?

I blew into the ground hose, and it was clear. How does the air get into the tank to replace the fuel that comes out, via the straight-to-ground hose?

ken750f · 10-03-2005

The "outside" nozzle is where the hose that goes to the ground attaches. The "inside" nozzle is for the hose that goes "somewhere"..............at least that is how it is on my 04 S3...................

Celt · 10-03-2005

i got the vacuum issue and took it to my dealer. he said some valve had collapsed and fixed it for me.

no more vacuum issue

geezerx · 10-03-2005

one line is a drain line for water or gas spilled under the filler cap but outside of the filler neck. the other line is the vent line for pressure equalization of the tank and has an in-line tipover valve.

the vent line is the line described as "going somewhere". It goes to the ground on 49 state bikes and connects to some polution ***** on california version bikes (unless all bikes are now changed to what would be called a 50 state version. the vent line would then connect to polution ***** on all bikes).

open the filler cap and look into the filler neck area. outside the filler neck area there should be a hole at the lowest point of the area outside the filler neck. this is the drain hole.

in the area outside of the filler neck there is also a small pedestal with a dished cradle in its center. the underside of the filler cap has a small rubber gromet which seats in the dished hole when the cap is closed. that hole leads to the vent line.

by blowing up through the drain line and feeling which hole emits the air. you can confirm proper connection.

the "plastic fitment" is most likely the tipover valve on the vent line. this valve must be vertical or it will close thus causing the dreaded tank suck as will a kink somewhere in this vent line.

best to get this sorted as there have been reports of tank damage resulting from suction.

PaloAlto · 10-03-2005

" One hose has a plastic fitment a few inches down, and goes "somewhere", the other one goes straight to the ground. "

Slope,

That "fitment" is a one-way valve that is supposed to allow replace air as the gas from the tank is used. If it fails, no air can get into the tank as you ride and use up gallon after gallon. That creates a vacuum and causes the sucking sound at the gas station.

You can check to see if this is the problem by removing the valve and going on a ride. If the valve is bad, you can a) replace it or b) discard it and just get a longer hose. My dealer suggested b).

"in the area outside of the filler neck there is also a small pedestal with a dished cradle in its center. the underside of the filler cap has a small rubber grommet which seats in the dished hole when the cap is closed"

As an easier fix while on a ride, remove the small rubber grommet (but keep it until you take care of the valve). Removing the grommet will let air get into the tank but may also give a bit of gas smell or slosh with a very full tank.

Bern