Why not get the old tank out , pressure test , get a good welder - braizer to patch it, when properly done and undersealed it would look as good as new . Good luck x

Steve at the YT channel "This Week With Cars" is currently working on the same fuel tank and has hit some problems fitting a replacement.

Good day Adam.And it is one off Jaguars problem with the fuel tanks as i understand. Due to water that is heavier than water and its lying at the bottom of the tank.I lost one of my xj6 executive's tanks due to that.Luckaly i had a spare tank of my series 1 xj6. I took both of my tanks to a company that do repairs on Radiotor's and fuel tanks. They galvanised mine but the only problem that they picked up was wen they had to fit the bid brass drain plug it wouldn't screw back as the lead was to thick on the threaded area.I let them closed ip that hole pemantly but they did fit a drain plug.That was the only issue that we picked up but i think that full tank will outlive the car.But most of the companies that do this type off work can safe your tank if it is only the bottom that is rusted.Hope you can manage to get hold of an good condition fuel tank ss i must agree with you that the price off a new one with shipping cost is very high.Greetings from South Africa and stay well.

“This Week with Cars” just posted a video: ‘Replacing a ruined fuel tank - Jaguar XJ6’. Same tank your working on!

HI adam: I had a leaky tank on my 10980 Suzuki LJ80. We brazed it over and over. It kept leaking. Finally i doctored it with JB Weld. Tried a spot, tested it. I JB Welded it about 4 times and it finally stopped. No waiting between dousing it with water. (pet heat on it with a heat gun on low). Tested it a few times and then the leak stopped. Hooray. KEY INGREDIENTS. JB WELD AND A HEAT GUN.

You gave it a good try to fix the fuel tank, at least you have identified the main issue now. Great video!

Congratulations 👏🥳 on 15,000 !!!!!! Well done Adam.

Nice work. I agree with the "brazing before sealing" comment.

Adam - I used POR-15 on a rusty tank and it worked perfectly. It can fix holes in tanks by coating the inside of the tank with an epoxy-type paint that is very tough. I highly recommend it.

A little tip: never use a regular metal screwdriver when working on a gas tank. work with either a wooden stick or plasticpiece . A small spark is enough and everything burns down! I once had a lot of luck with the gas tank of my 77 S-Class

When I had problems with the fuel tank on my XJ40, one was for sale at the price I paid for the whole car, in as bad condition as mine. Now the car runs with a mk1 Mazda 3 plastic fuel tank, but I understand that it might not pass MOT as is. Where I live, in Canada, there is no MOT except if a car was not registered and "on the road" for more than one year.

The sending units on my 1989 xj12 is behind the rear lights- I'm guessing the later tanks are quite different! I was just about to order one- good job I watched this video.

Well it was worth trying! Nothing to be lost by trying some sort of sealer. I'd be removing the tank, cleaning off the outside around the seam, do a temporary external seal on the seam with some sort of RTV, fill tank maybe 1/3 full with a citric acid/water mix to remove corrosion, clean out with lots of water, dry then sealant internally, then remove RTV from outside and see what happens. Some time invested but not many $. But do what suits you best! Thanks for the video.

Def worth a try Adam shame but at least you now know what it needs all the best donny

Hi Adam I feel for you mate all that work for and you had to put all back to use on one tank but made great content really enjoyed it

I used POR15 tank sealer (on my motorcycle) it has to be worth a try even if you only do the bottom half of your tank.

Righty tighty, lefty loosy!!😝

To clean out the rust, use some white vinegar to cover the badly rusted areas, let it sit in the tank over night. Drain and flush with bicarb of soda to neutralise the vinegar. Flush several times with fresh water. Spray some WD40 inside the tank to dry and displace the water and slow surface rust from forming. Changing the filter a couple of times will help. I have done this on my car with great success. Good luck, if you have further issues try this method.

Maybe worth a try for you it cheap and easy. Many years ago l had a a mk1 Cortina and the base of the tank was perforated with rust, cleaned all loose rust off and then coated with several layers of fibreglass matting and resin, repair lasted for many years without any further leaks.

Couple thoughts: First - I would consider brazing the seam before sealing. Its a simple enough process that doesn't require as much skill and will not damage any otherwise sound metal. You will put enough heat into insure the moisture is gone and the solder will flow into microscopic pores. I would only do this if its leaking at the seams ONLY. Secondly, If you do go with a sealer (I don't lean for or against at this point) I would do a simple pressure test after it's cured. If it can hold 10 psi for several minutes I would trust it - I don't think sloshing fuel would create that much. Sorry it didn't workout but it's still good information and made a worthwhile video. You may feel you wasted the better part of a day, but I don't think I wasted my 26 minutes watching this.

I just replaced the tank on my s1 xj it had a good run was definitely time..

It's a long time ago now but my aunt in the US had an XJ6 with leaking tanks, if I remember correctly, her local classic car mechanic fixed the problem by removing both tanks and added molten solder to inside of the tank and sloshing it around so that the solder finds and seals the leaks.

Hello Adam, I’ve been following your very informative channel for a few months and learned a lot. Thank you. Today, a question - I have a 1988 series 3 V12 Sovereign and have just completed a total cooling system overall.Replaced water pump, etc etc. All is well, no overheating and running at constant 90-93 degrees. She was standing on ramps with front end lifted and whilst engine running, fuel started squirting into the engine bay from the r/h wheel well. There’s a black canister which look like it’s overflowing. What is this and where do I look for the problem? Can you help? Peter van Rooyen- Australia.

Personally I wouldn't use a sealer. You have to take the old one out, Change it. End of problem. If the sealer fails you only have to do all that work again. Buy cheap buy twice.

If you’re going to weld on the tank, make sure it has a flow of argon inside so it doesn’t go boom.

Interesting video.

As others have said - don't write off the tank just yet. If you do any brazing check out other youtube videos - sure I have seen some old tanks being brazed but filled with water? May be wrong but there should be info out there. Interesting video and good luck

Buy just another tank. Thanks for sharing this inspiring video.

Further to my last comment; I was easily able to power wash the inside of the tanks because of the ease of access to the inside via the sending unit apertures behind the rear taillights. Ths one would be a lot harder.

Good evening I pray all is well, can i use a 1983 jaguar XJ6 4.2 engine with California emissions in a 1987 jaguar Xj6 4.2 federal admissions?

Does anyone know where to obtain a rebuild kit for a Ate master cylinder from a 94 XJS?

I saw the burnt Series I XJ lurking on your site… can’t you borrow or buy a tank from that ? I’m sure a seal or repair of the leaking seam should be possible with care.

The tank has to come out either way, so why not pull it out so you can see what you're dealing with? That's an option people with "normal" cars with a single tank don't have! I've mentioned before Adam but I live in the UK and have a small company with a few postal contracts in place to ship the products we sell around the world. I'd be happy to see if I can forward packages to you cheaper.

Pull the tank, put water in it, seal it up, pressurize it, find the leaks, braze the leak, repressure, Bob's your uncle!!

Don’t know if it’s cost effective but I was under the impression someone could slice the tank in half and weld the cracks and holes then weld it back together after it’s pressure tested first to find the week areas.

I assume the leak doesn't look like it's coming from the hose that goes between the tank and fuel pump?

I am sure you are disappointed but you have a few options. I’d err on the side of a new or high quality used tank if you can find one.

Well,luckily you can remove that tank and have it brazed. Don’t mess about with sealant or liner, it’s not a proper fix. Car looks in nice condition, I’d be interested to see what it’s like under the rear seat though.

I RAN INTO THE SAME PROBLEM. the only way to go is to new fuel tanks.

Question: My 75 xj6 (non efi) sat for a few months and when I tried to start it the fuel pumps are not working. Put power to the pumps directly and they work. Tried bypassing the cutoff switch but still didn't work. Could the tank switch be the issue?

The contact pump's are unreliable and in the long term the solid state SU's are totally reliable, problem is they can overpressure and find leaks. Be worthwhile taking out that brass plug on other side when other tank is in use. Unlucky with tank. There was a day when they repaired tanks. Not withstanding safety and purging it might be possible. He any duty soldering iron springs to mind for a patch. Idea??

Shame. I hope you can find a good replacememnt. I've tried sealer a couple of times but never had much luck. It didn't seem to last long so I had to replce the tank anyway.

Are the tank seams welded, brazed or soldered, because this new ethanol E10 fuel dissolves solder, I know because my carb floats soldered seams dissolved, and the carbs. flooded. Best to have the tank seams welded, snd the tank lined with Anti ethanol fuel liner ! Good luck Adam !

Hello Livingwithclassic! 👋 I'm rebuilding a 1978 XJ6L and rebuilding my KZfaq channel that KZfaq deleted....

Adam, if you review your video, you can see it was still dripping water steadily albeit slowly during your last test. Good content though.

Frustrating result! How complex is the tank? Might it be possible for a local sheet-metal worker to make one?

Hey Pal I'm all the way from south africa. I've been struggling to find parts locally for a customer of mine. Could we get in touch to perhaps to chat a bit more? Thank you. Passionate subscriber.

JB weld it

Lefty loosely. Righty tighty.