Fuel Tank Removal

A lot of the recent work has been about building up to repainting the chassis. Another step on that journey was removal of  the fuel tank so that I could inspect, clean and repaint the area beneath the passenger seat. Given that the car had, by now, been laid up for 20 years, I was also expecting to have to replace the fuel tank because of internal rust.

The fuel tank revealed

The tank is hidden away beneath the rear seat and a protective cover. With the seats out, accessing the tank area was easily and simply a case of undoing all the bolts on the galvanised panel under the rear seat.

Cover panel over the fuel tank

The cover panel hinges towards the front on a simple scroll hinge and can be unclipped or slid out. With the tank exposed, I disconnected the wires from the fuel level sender.

Fuel level sender

I removed the Ligarex clip on the rubber join of the fuel filler pipe in rear wheel arch, and the Ligarex clip on the nylon breather  pipe at the tank end.

Curved pipe is the breather

The next task was to remove the fuel pick up tube from the tank. This goes into a curved guide tube in the tank, which steers the pick up tube down to a fuel filter. Over years, the pick up tube hardens and so it can be very reluctant to be released from it's guide tube.

Tank cross section. 'A' is the guide tube to 'F' the filter

Since the nylon pipe goes down a metal guide tube, on the outside of the tank there is an outer black rubber sealing tube over the nylon tube and guide tube spigot. This outer tube is a tight fit to provide a fume-free tank seal. When removing the nylon fuel pick up tube from the tank, it's important not to kink it as it can be brittle and so crack and leak. The difficulty is that as it is pulled from the fuel tank spigot, it has to be pushed through the sill box section beneath the rear passenger door on the right hand side of the car.

The pipe is secured along the sill, so those brackets needed to be removed to provide some slack. Removing the brackets only provides a limited amount of slack because the pipe passes through a hole in the 'B' post which retains the pipe close to the car body. 

With the fuel pipe free in the sill, I began to pull on the black rubber outer hose at the tank end -  and at the same time readied myself to feed the freed pipe through the sill. Unfortunately the pipe freed suddenly and, as I pulled it through the sill, it buckled and creased. I can't tell if it is is holed and will leak, but will not take that chance. Since the outer sills are off and the engine is out of the car, I might as well replace the fuel pipe. if only for peace of mind.

The tank is a tight fit in it's cubby hole and I've read several posts on social media and DS forums from people who have struggled to see how to get the tank out. I think the issue was difficulty in getting the tank past the brackets that hold the metal over-straps. I didn't have any trouble and I think that might be down to technique.

There are a number of packing rubbers around the perimeter of the seam of the fuel tank. In some places these rubbers are slotted and are just pressed on to the tank seam.

Slotted packing rubber on the tank seam

In other places the packing pieces are tubular and are held idown on top of the seam by simple folded metal tabs.

Tubular packing rubber under metal tab

The tank is secured in place by two metal straps.

Metal securing strap

These are effectively hinged at the back end of the tank recess.......

Metal strap and rubber packing piece

........and are screwed down at the front end.

The ends of the straps are screwed down

Undoing the long screw released the clip at the front. 

Strap and retaining clip
(photo credit: unknown)

The strap hinged back, releasing the rubber packing piece at the hinge end.

Packing piece at the hinge end

At the screw end, I was able to access another slotted packing piece pressed on to the seam.

Slotted packing piece under the metal strap

Withe the wires, pipes and hoses disconnected, the rubber bumpers removed and the straps undone, the tank should lift out. I think this is where some people have struggled. The front end brackets that the metal straps screw down to, are folded over the seam of the tank and get in the way.

The strap retains clip sits on the seam of the tank

They seem to be hinged, but can't be folded down as the tank is in the way. Even if they could be folded, that wouldn't really make any extra clearance to remove the tank. The solution is simple: with the rubber packing piece out of the way, the brackets can be pushed down vertically.......

The strap clip can be stood up

........then unclipped and completely removed.

Removing the strap retaining clip

This can be done with the tank in situ and then gives enough room to free up the tank. With a bit of wriggling to release the fuel filler pipe from it's tunnel in the chassis, the tank was free.

Fuel tank removed

So what did I find? Well, it all looked very good. There was some surface rust near the tunnel where the filler pipe goes. This was probably because of the ingress of mositure and spray from the rear wheel arch. I found telltale signs of mouse action. Almost certainly as a result of the car quietly sitting in a barn for 14 years.

Evidence of mice.....

Other than that the floor was rock solid. I will probably clean it out, but may not even bother to paint it.

Floor under the fuel tank

With the tank out, I was able to drain the fuel from it. The brass drain plug came out easily. These can be fused in place with the risk that the brass nut becomes rounded as you attempt to remove it.

Fuel tank drain plug

I was quite surprised to find that there was no fuel filter inside the brass plug. 

Without filter........
It wasn't rattling around inside the tank so must have been removed at some point in the past.

There should be a filter on the end of the drain plug

I was even more surprised to see that, although stale, the old fuel came out clean. No signs of rust and no obvious residue left inside the tank. I blew compressed air through the tank to remove fuel vapour. and put an endoscope camera inside for a better look. I was amazed to say the least!! The tank was clean and shiny inside. No signs of rust. 

The view inside my tank. Shiny!

Considering the age of the car and the number of years it sat un-used, I expected to find the tank a disaster. 

This is what I expected to see...
(photo credit: Carter Willey)

In fact I'd already bought a new replacement fully expecting to have to throw away my original tank. I may yet regret it, but I think I will keep this tank and sell the replacement tank to free up some funds. I will probably have to de-glaze the tank to remove any 'varnish' left by the old fuel, but now I'm worried about 'flash-rusting' so will leave things just as they are for the moment.

Another view inside the tank