Tribulations of fuel tank replacement!

[Ceejay 72]

Having decided that the tiny leak from the base of my fuel tank was only the start of potential ongoing problems (four previous repairs), I decided to replace it with a new one.
I thought this would be a simple process, but no!
A new tank, longer filler hose, new sender locking ring and gasket were all purchased from a well known supplier.

A trial fit showed that the mounting flange holes did not align with the threaded support brackets in the boot, so the holes had to be elongated by about 1/4 inch.
The new tank had a drain plug, unlike the original and this fouled the boot floor, so a hole had to be cut in the floor to accommodate the plug.
The new filler hose was too long and had to be cut down by about 1 inch.
The vent pipe on the tank was too long by about 1 3/8 inches and had to be cut off to allow the fitting of the short hose length and the upper vent pipe section.
A trial depth check for the fuel pick-up pipe showed that the tank was effectively about 2 inches deeper than the original, when measured from the threaded spigot to the tank floor. This would have left the pick-up pipe 2 inches short of the floor, so losing effective capacity. I compensated for this to a certain extent by using the lower spigot, where the blanking plug normally sits. This gained me just over an inch.
Finally, I found that the depth of the thread on the spigot was longer than on the original and the nut securing the pick-up pipe bottomed before the olive reached its seat. I made up a copper dished washer which I slid over the pipe and which allowed the nut to tighten down on the olive.

Has anyone else experienced these problems?
Chris

[new to this]

I fitted an alloy fuel tank in my brothers car , been in there a few years now , i put spacers under tank to lift it a bit so the tank wouldnt sit in water ,the only mod i had to do was cut the rubber filler neck down a bit
when he got his every one was out of stock of any fuel tanks we took Wards display tank

Dave

[tvrgeek]

" so it does not sit in water..." Well. I added a scupper to the bottom of the boot. Not having one was a design oversight I believe.

[DJT]

" so it does not sit in water..." Well. I added a scupper to the bottom of the boot. Not having one was a design oversight I believe.

Why? In 30+ years of Stag ownership I have never experienced water inside the boot.

FWIW The original boot floor had a few holes (about 1/4”) in it and these were fitted with tapered rubber bungs.

[Neil in Deal]

If I have to replace the tank in my car I think I'll have to splash the cash on a Wards alloy one.
I saw one being fitted at Faversham, so had a chance for a good look.
'tis a thing of great beauty......and it holds more than the standard tank....and it won't rust out, probably outlasting me !!
Stay safe,

Neil.

[trunt]

Having decided that the tiny leak from the base of my fuel tank was only the start of potential ongoing problems (four previous repairs), I decided to replace it with a new one.
I thought this would be a simple process, but no!
A new tank, longer filler hose, new sender locking ring and gasket were all purchased from a well known supplier.

A trial fit showed that the mounting flange holes did not align with the threaded support brackets in the boot, so the holes had to be elongated by about 1/4 inch.
The new tank had a drain plug, unlike the original and this fouled the boot floor, so a hole had to be cut in the floor to accommodate the plug.
The new filler hose was too long and had to be cut down by about 1 inch.
The vent pipe on the tank was too long by about 1 3/8 inches and had to be cut off to allow the fitting of the short hose length and the upper vent pipe section.
A trial depth check for the fuel pick-up pipe showed that the tank was effectively about 2 inches deeper than the original, when measured from the threaded spigot to the tank floor. This would have left the pick-up pipe 2 inches short of the floor, so losing effective capacity. I compensated for this to a certain extent by using the lower spigot, where the blanking plug normally sits. This gained me just over an inch.
Finally, I found that the depth of the thread on the spigot was longer than on the original and the nut securing the pick-up pipe bottomed before the olive reached its seat. I made up a copper dished washer which I slid over the pipe and which allowed the nut to tighten down on the olive.

Has anyone else experienced these problems?
Chris

Been there done that..Contacted supplier who did not seem interested.

I ground the head down (its a huge headed bolt) to clear the floor, then elongated the mounting holes enough to get the drain plug to line up "just" enough to potentially remove it. Also shortened the vent but did not need to shorten the filler. I used a non standard fitting on the pickup so did not come across that particular problem.

Terry

[Jeff]

I fitted a new replacement a few years ago from Rimmers and had no problems whatsoever.

[tvrgeek]

Why? In 30+ years of Stag ownership I have never experienced water inside the boot.

FWIW The original boot floor had a few holes (about 1/4”) in it and these were fitted with tapered rubber bungs.

If the seal is good, it should not, but it was clear that at some time water had sat in my boot. Life is full of "should" and then there is reality.

[StagJonno]

Have heard of condensation forming on the nether regions of fuel tanks - suppose that's a function of daily & seasonal temperature swings coupled with humidity.

[Lingen]

I think another source is rain-based. I have always found that on opening the boot during or after rain, water pours from under the rear chrome trim in to the boot. Unless you remove the carpet and dry it properly, it will create a very damp atmosphere in there, which under the right conditions will condense out on to cool surfaces like the tank. When I removed mine many years ago, I found that Triumph had glued a piece of felt underlay right across the bottom of the rear of the tank, presumably to insulate it from the floor. This was efficiently soaking up any water in the area, and it was behind this felt that it had corroded slightly, creating pinhole leaks. I removed the felt, repaired the tank, and then undersealed the bottom before replacing it without any felt. That was about twenty years ago, and rather surprisingly, I have had no trouble since.
Mike.

[DJT]

I think another source is rain-based. I have always found that on opening the boot during or after rain, water pours from under the rear chrome trim in to the boot.

Mike,
When I refitted that trim piece after restoration, I filled the top and bottom gap between it and the bootlid panel with black mastic. It isn't noticeable against the Carmine paint and eliminates any rainwater gathering in that area and falling into the boot.

[Lingen]

DJT.
When I fitted that trim piece to my Carmine red stag after restoration I did exactly the same, and the problem went away on mine as well!!
I suppose my suggestion was for those who haven't sealed it as we have, and might still be getting a wet boot.
Mike

[Stagdad]

I found all of those problems with the pattern tank i got years ago, you forgot to mention that they are deeper so the boot boards don't fit. I got rid and found a good original.
Cheers Steve