Your car's fuel tank is vital, because without it you'll be going precisely nowhere. So, it makes sense that it's as structurally sound and safe as possible.
To that end, a lot of manufacturers have made the switch to plastic fuel tanks, because not only are they safe in a crash, but also they don’t corrode and they weigh less.
Older cars, however, relied on good old metal, and those old tanks do fail. Ultimately, you may well need to replace it.
Changing a fuel tank is a pleasingly simple job in that there are usually no specialist tools needed. However, make no mistake, this is a big, BIG job. There will be a lot to remove, a lot to work around a lot of things to be careful of.
There is also a degree of danger when dealing with a fuel tank, what with petrol's propensity to go bang at the sight of a spark. This is less of a concern with diesel, which needs compression and heat to ignite.
No matter your fuel type, there are five things you need to know before you tackle this big job.
01 Drain the fuel
Drain the tank completely. Then check it and do it again. And just to be sure, do it again. Store the fuel in a proper correct container, too – not old jars or ice cream tubs. Some cars will have a drain plug on the bottom of the tank that you can undo. If you struggle to get it off, do NOT try to drill a hole in it – drilling metal will heat up the metal and cause sparks, which vastly increases the risk of you being turned into human toast.
02 Do it in a well-ventilated space
Even when the tank is completely drained, it’s still going to reek of fuel. As such, changing the tank is a job to be done somewhere well ventilated, not in your integral garage with the door closed.
Fuel fumes can lead you to pass out, which could cause injury. But more than that, in the case of petrol the vapour is extremely flammable. One errant spark and it’s game over.
03 Take notes and take pictures – be organised
As we said, changing a fuel tank is a big job. You may need to drop the suspension, a driveshaft might need to come out, you'll have to unclip all the fuel lines, the list goes on.
Do yourself a favour and bag up each set of niuts and bolts, and write on the bag what they’re for.
Take pictures of things being before you take them off so you know how and where they should go. You’ll be glad you did. This tip comes from painfully won experience.
04 Don’t cheap out on the fittings
Are the breather lines looking rough? Have the fuel line clips corroded? What about the fuel tank straps and the bolts, have they rusted? Don’t put them back on the car then - replace them instead.
Rust loves a bit of osmosis, so if you put rusty bits tight against the new tank’s metal, you’re inviting it in.
As for the other parts – this is your fuel system, not only is it important, it’s also extremely dangerous. Do you really want to use knackered old bits and then just hope for the best? You’ve got the car apart anyway, so get new gear on there.
05 Have a fire extinguisher
Fuel is, by its very nature, flammable. That is kind of its job. So please spend a few dollars and have a fire extinguisher to hand. And we mean right by your side, not in an understairs cupboard. It will stop a moment of panic from becoming a car-destroying inferno.