I’m dealing with a leaking fuel tank. I was going to remove the rust with the electrolysis method, then coat the inside with the POR sealant. Seems like a lot of effort to retain the original tank. Anyone have thoughts about the quality of the replacement tanks vs. the OE repair?
Douglas -
False economy to patch - in my opinion. 
I replaced one of my tanks (RH side) and I got the replacement from SNG Barrett (US). I took advantage of a free shipping offer they were running and got the two - Right and Left. They were of the highest quality and it fit perfect. Big job but not too bad - have not mustered the energy to do the LH side yet.
Ian
1984 XJ12 VDP Euro-Spec
1985 XJ6 US Market Car
Thanks. That was what I had come to think - a lot of work to restore. I have it out and used a fiber optic instrument to examine the inside and it is very rusty. Biggest concern was the quality of the replacements. I am going to do the other side as well now that I know what the inside of one looks like.
Doug
The inside of the tanks is coated to prevent rusting, Douglas…
Over time the coating may delaminate over time, exposing the metal - which will invariably rust. Apart from finally rusting through the tanks; delaminated coating and rust flakes will interfere with fuel feed - blocking filters etc…
Frank
xj6 85 Sov Europe (UK/NZ)
I’m based in the UK but have also had replacement tanks from SNG Barrett for my Series 3. They were actually made in Canada and proved to be perfectly good quality, fitted first time, screw threads were correct, no problems since.
For the work and effort it takes to remove and replace the tanks I’m inclined to agree that trying to repair an old,rusty, leaking tank isn’t worth the time.
Regards,
Andy
Thanks. After I had a look at the inside with this handy little fiber optic viewer I obtained via Amazon, I thought de-rusting and sealing might not be good long term. Good to know the replacements are high quality.
I have a series 3 XJ with leaking RH fuel tank and need to remove fuel tank to fix how do you get it out? thanks terry
tmcgrath@bigpond.com
Terry,
I have removed nine Series III XJ6 fuel tanks and there is a lot to it. The Jaguar Series III Service Manual covers most of the steps and I usually refer to it regularly throughout the process. In general, after you have drained the fuel tank, you need to remove: the right rear wheel/tire, rear bumper, the tail light, the fuel cap, the wiring to the fuel sender, the finisher panel beneath the tank, a bunch of fuel hoses and pipes, the rear muffler, the bolts holding the tank in place, and some other parts that I probably forgot.
You should also order new seals for the sender, drain plug, and fuel cap as well as new fuel hose so that you have them on hand for reinstallation as the originals will be old, cracked and not reusable.
Fuel tank removal is discussed occasionally on this list so there is probably a lot of other helpful information in the archives if you search for “remove fuel tank”.
I would estimate that it took me the better part of a day to remove the last fuel tank, but that was with the benefit of having done it before several times. You will also need to raise the rear of the car in order to have enough height to lower the tank out of the fuel tank well once it it free. Some of the parts may take extra time, force, heat, lubricant, and occasionally strong words to remove. 
Paul
I would like to say thanks for that detailed description but you ruined my week!
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When you drain the tanks it will ruin your driveway too. Get a tarp, it’s messy even when you’ve pre-drained it and you’re just getting the remainders out.
Terry,
John makes a good point about draining the fuel from both tanks. You can not count on the valves to seal perfectly and fuel from the other tank will probably leak and make a mess if you don’t empty all of the fuel from both tanks. Even with that you will need to depressurize the fuel system and some fuel will still likely spill out. Each tank holds about 12 gallons, and you can’t trust the fuel gauge to be accurate. So drive the car until both tanks are just about empty and then drain the rest into a large container to avoid spillage. More than one Jag-Lovers member has underestimated the amount of fuel in the tanks and ended up with considerable fuel spillage when draining the tanks.
Paul
Have you confirmed that the tank is actually leaking, Terry - not overflowing due to failed changeover/return valves?
Frank
xj6 85 Sov Europe (UK/NZ)
When we restored my car in the late 1990s, we repaired the tanks with one of the standard products. It worked fine for more than 15 years when I started having problems with rust particles in the fuel system. A good performance, BUT, at that time, there were absolutely no replacement tanks available.
1 The tanks rust due the shape and internal condensation so keep them full.
2 Particles in the fuel system are a total nightmare
3 When the tanks have any corrosion, replace them if new are available.
Peter,
Some of us have installed inexpensive inline fuel filters between both fuel tanks and the fuel changeover valve to beter protect the fuel system. Attached is picture of those fuel filters in my 1990 V12 Vanden Plas circled in red. In the past 22 years I have owned two running XJ6s, three XJ6 parts cars, and an XJ12 and I have only had one leaky fuel tank (in my former 1984 XJ6 Vanden Plas). I sold five of the six fuel tanks in my parts cars and they were all in decent shape inside with no leaks. The sixth parts car fuel tank was crash damaged and no longer usable, even though it didn’t leak with a lot of damage to it.
It is my experience that the original fuel tanks are robust. I had another leaky fuel tank I would remove it and unless it was badly rusted I would just get it repaired and then reinstall it.
Paul
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Paul,
I did the same to keep things going until I managed to obtain replacement tanks. The extra filters helped, but the system seemed to be sensitive to even the smallest particles. We spent a few years on the west coast of southern Italy. It was a very humid environment and I think it caused a lot of harm. When I drained the tanks, there was a surprising amount of dirty water at the bottom.
I had tanks that weren’t touched for likely 10 years and tanks that were not touched for likely 40+ years. Both had no more than a few drops of water at the bottom but lots of rust and tar in the older ones. Neither were stored full but they were inside or covered.
If the caps seal well (!) there won’t be too much water getting in… but do drain your tanks some time!