Fuel tank, to change or not

XJ
1

I’ve been running on LH tank which the PO had replaced and can’t decide whether or not to replace the right hand tank. The car has been sitting for a few years and I think the tanks were empty. I put 5 litres into the left hand tank today and watched what came out and although it is slightly coloured it isn’t full of rubbish. Looking into the tank through the filler I can see light rust on the tank sides. I’ll look tomorrow with a bore scope to see if I can see anything really nasty but I’ve run the car around with the fuel in the tank and the outlet blocked and no sign of a leak. Given it’s a series 1 and replacement tanks only seem to be available updated so other bits are also required I’m up for around 500 dollars or so to replace it with all the other bits, I’m considering filling the tank and with a filter before the pump running say 30 litres through to see what shows up in the fuel.
What is the perceived wisdom, give it a go or bite the bullet and shell out for a new tank?

Ian

2

Hi Ian,

I’ve played this game with alot of old cars in general and multiple Series 1’s. A new tank is probably not necessary unless it is leaking.

First it wouldn’t hurt to completely drain the tank to get out any water that inevitably collects because of the hygroscopic properties of ethanol-laced petrol (easy with XJ’s because of the drain plug) and clean the screen around the pickup tube. Then it’s not a bad idea with an old, dirty tank on a series 1 to install a clear plastic fuel filter Before the fuel pump temporarily. Here’s one I use alot on amazon: https://tinyurl.com/y757l2wp .

Then, change the main fuel filter and inside the body of the filter (glass I’m guessing because I know yours is an early car) I drop in a little neodymium magnet or 2 (also an amazon thing) - this doesn’t hurt anything - I’ve had one in there for years and it looks the same as when I did it. This’ll just help keep any rust particles from getting any further. On the later Series 1’s with the metal bodied filter you can just stick the magnets to the outside cause it’s steel.

Also - and this is overkill - On my cars I install a final glass bodied filter in the engine compartment permanently so I can see what’s what. image

Finally if you ever plan on letting the car get rained on, be sure that the gaskets/seals/drain holes around your tank inlets are there and intact. On one of my cars a super-genius PO left out the main gasket under the chrome cover and when it rained water got in the tanks stopping me mysteriously dead in my tracks until I figured out what the heck was happening. Annoying.

So moral of the story is don’t be too hasty to buy a new tank and accouterments if it doesn’t leak - Once you get it clean again it’ll be fine.

~Mike
72 XJ6 (x2)
73 XJ6
85 XJ6
84 XJS

3

I did much the same as this - fitting paper filters just before the float bowl. I fitted my internally inspected second hand tanks about three years ago. No dramas. Would also remove and clean the carburetter float bowls - mine had about a 1/2" of rusty sediment in the bottom of each. Paul

4

No such thing, when it comes to fuel!

Tweety had:
-a filter just after exiting the in-tank pump

  • the sediment bowl
    -a frit-style filter between the sed bowl and the carbs
    -the three brass screens under the bowl banjos.

Kept the fuel bowls pristine!

1 Like
5

Opinions and experiences vary.

I’ve always been lucky enough to find a local radiator shop that also cleans gas tanks and have had good results…typically about $75-100/tank. They can’t perform miracles, naturally. Some tanks are just too far gone. But, if you don’t mind the labor to remove the tanks…no small task…a professional cleaning might be a viable mid-range choice. Certainly less money than new tanks.

Cheers
DD

6

Thanks all, filters ordered I’m going for the clear glass ones which can be cleaned, one before and one after the pump plus the bowl filter in the engine compartment. The carbs were rebuilt late last year when the new LH tank was installed so no rust in the carbs, as yet at least.

Ian

7

Man after my own heart. Mike’s process is ideal imo.
I do the same…

I am very overkill when it comes to coolant and clean gad lines on these cars.
Specks of debris easoly clog float needles, etc.

These cars reward such perfectionism.

I considered swapping the glass bowl over to the one i intend to keep as it was missing, but chose to get a later bosch type as used on the s3.

Always liked the glass bowl concept as i too like to always be on top of things.

I use the exact same glass filter in your photo just before carbs.

I agree. If the tank isn’t leaking, and depending on overall condition, most often one can simply drain the sour gas.

Removing plug at tank base yields a screen, make sure it’s cleaned. Blow all the lines of course…

If you need to repair fuel gauge sending unit, which is most certainly seized or damaged, removing the cover within wheel well for its access creates perfect oppty to do it all…
The filler neck alone is doable too.

Can’t recall tank capacity at moment. 15gal us?

Anyway, options:

it just bothers me not flushing it out a cursory amount to eliminate at the very least bassic corrosion and sediment.

Go to walmart or wherever, get white vinegar. They sell by gallon, about 1.20$ ea.

Or use evaporust…recommended and reusable.

Put the drain plug back in, and accessing hole where gas gauge was or filler cap, i simply use a slightly modified hand held weed/grass hand pump type sprayer. The kind that has wand attachment. Cheap.

i spray and spray the interior of the tank, repeating for a day or so, whenever i think about it then allow sit overnight.Repeat. Close filller cap each time and tape up gauge hole to keep from evaporating too quickly.

Repeat and drain again. Then spray with water, ue ccompressed air to dry and fill w gas to guard from flash rust.

Or just fillthe tank w vinegar. Worth $20 or so.
Then allow sit a couple days or more, drain, fill w gas, drain, done.
Keep filled w gas to protect tanks from ever rusting again.

Vinegar really works well for rust.

Flushed a cooling system w water, no rust left the system, one i knew had corrosion.

Filled w vinegar (the 1% solution wil not hurt aluminum) let it sit a weekend or so…

Holy smokes. drained and orange gunk water poured out.

now i have an orange driveway i haven’t been able to clean despite several products and scrubbing! Need to go muratic acid route or sand blast…damn iron oxide.

Anyway, that’s what i do.