tr7triumph.com

Since getting the 7 back on the road after a 20 year lay up. That's 1000 miles covered in about 2.5 months . Still so much to do but it's on the road. My list of jobs for the winter gets ever longer.

One Immediate issue is the boot stinks of fuel after I fill up with petrol. I can't see any leaks so wondering what else I should check? I took the access panel off in the boot to check and got underneath. Not had the fuel tank out and would rather not if I can help it

Any advice much appreciated.

My tank rotted from the inside out a few years ago. The first pinholes appeared around the bottom leading edge. I guess that's where the water collects inside over 30 years, at the lowest part of the tank. I couldn't see petrol on the garage floor but I could smell it. The pinhole was so fine the fuel was evaporating before it had a chance to fall on the floor. I had to run my hand under the tank to find the leak. Once drained I attacked the leading edge with a screwdriver and created lots of holes.

If the smell only occurs after filling up and you definitely have no tank perforations or fuel hose leaks, I'd suspect the rubber filler pipe and connections between rear deck and tank. Leaking petrol could sit on the flange halfway up the tank and evaporate but you've had the access panel off to view that. Is the filler cap's rubber seal intact? What about the rubber seal around the tank's sender unit? I've seen them perish as well.

Replacing the tank isn't as bad as replacing the heater matrix and associated pipes........

Adam

I would check the small rubber hose that is part of the fuel venting system. On my cars it usually was rotted right at the connection to the filler neck. The other end connects to the filter you will find in the same area.

You can access it from the odd shaped panel inside the boot on the right side just under the filler cap.

Edward Hamer
Petaluma CA

As you are in Glasgow I presume your car is Euro spec, so no filter near the filler neck?
With the tank full it is possible that some fuel will get out through the vent hole of the fuel filler cap under cornering, especially LH.
And you only need a few drops to smell the petrol.

Tonight I brimmed it and there were some signs of fuel on the outside of the tank. More like damp. I'll check no fittings have perished before removing the tank. What needs to come out to get the tank out?

From memory,

Removed the fuel filler pipe, both rubber and steel and the fittings from both rear deck and tank. Removed exhaust from under tank. Removed tank sender unit. Disconnected top links / tie bars, propshaft and rear shox to rear axle enabling it to be lowered. Undid rusted nuts / bolts securing the tank straps. On mine, the tank straps were badly twisted from undoing the corroded nuts and were junked afterwards. I needed lots of room underneath the car so jacked it up as far as I could under the rear jacking points.

Once the tank was out i stuck my head in the space and cleaned up the areas around the tops of the chassis legs etc.

From memory we have the option of ss tanks now. Will try and find the link to them and post here if I have any luck. I always said that if I had to replace mine I would do it with one of them. However, I had mind done about 12 years ago so hopefully it will be good for a few more years.

On a side note the winter jobs list will always be there. I have had winter jobs now since I have had her and each year I seem to fill it again.

The most like faults have been mentioned, however a few others.

Check the hose from tank to the pipe running to the engine bay.

Check the sender fitting is not weeping between it & the tank. On one of mine, the spot welds were fine, but the contact area was weeping enough to smell, but not drip onto the floor.

Check the vapour separator, [if you have one], as they crack with age.

One last suggestion. Fit lock nuts to the top of the tank strap studs. 2are in the engine bay, & 2 in the bulkhead behind the seats. This will allow the nuts to be removed from the studs. If not done the studs screw out, & wind the straps into pretzels.

Hasbeen