2005 S-Type (Gas tank replaced in 2008/Recall)
Last month replaced fuel pump/gas tank gasket and new lock ring.Lock ring won't seal when fueling. Jaguar say's the tank starts to distort/bow when tightening the lock ring
and gas tank needs replacing. My Independent mechanic wants to try a sealant. Anybody out there with this experience & any particular sealant recommended??

 

Welcome to the forum.

Can't help with any sealant suggestions, but was the tank previously leaking? I'm wondering if the new lock ring is defective, perhaps not parallel or something like that. Do you hopefully still have the old lock ring? If so, I'd certainly try reinstalling that one and see if that helps.

 

The leak only occurs when filling the tank. The leak did not occur until after replacing the fuel pump. The lock ring had to be replaced because it was cracked. Both the Jaguar & Independent tech don’t see any issue with the new lock ring. Again the Jag tech is saying when tightening the lock ring the gas tank is warping not allowing it to seal. I don’t want to replace the tank I’m thinking like the independent mechanic to use a sealer on the lock ring.

 

I had similar problem with my S Type.The lock ring fit only one certain position, and the ring itself wasn't a complete ring. There was about a 1/4 in. gap that made all the sense in the world once I figured it out.

 

My guess is the tank is warping because the guy is overtorquing the lock ring, trying to stop the leak.

Three pieces of the equation have to work together: Tank, seal, and lock ring. You've replaced the seal and lock ring, but kept the existing tank. Maybe the new seal doesn't fit quite right, or the lock ring doesn't fully seat for reasons still to be determined. You had a combination of all three pieces that previously worked, even with a cracked lock ring and a tank that supposedly can flex.

What changed? You replaced two thirds of the parts and have a new problem. That makes me highly doubt the tank itself is the issue. Are the new parts defective? I can't tell from here. Are the pieces okay but not fitting together properly, as previously mentioned? It's hard to tell from my easy chair by the fire, but it's a possibility.

Is sealer the fix? I highly doubt that, and would not recommend that path. But if your mechanic wants to try it and will guarantee his work, that's his call. Sorry I don't have a simple answer for, such as order improved seal #XYZ. If you do try new parts, get them another source in case the first ones came from a bad batch, still sitting on the same shelf.

 

This may sound like the dumbest product name of all time. Seal all. It comes in a tube and i have had great success with it on gas cans. Metal and plastic. It dries to a hard yet flexible seal. Only product i have found to seal gasoline completely while filling a gap or hole

 

Interesting stuff. More info here, from the manufacturer:

Seal-All | In The Home & On The Job Products


Most products like that won't stand up to gasoline, so this is different. Not sure I'd want to use it in this application, however. From what I've read, it makes a permanent bond. When (not if) the fuel pump needs to be replaced at some later date, that poor mechanic is going to be cursing your name. Maybe provide your full name, address, and phone number? That way, the current mechanic can write your contact info with a sharpie on the tank. That will make it easier for the next guy to curse your name when the locking ring won't release...

 

First thanks for everybody's input. I would use a pliable sealant where you can remove to lock ring to get to anything you need to. The Jaguar tech told me the sealant could (possibly)
cause a issue with the gasket.

 

I have a question for you - are you lubricating the thread of the ring before you tighten it? When I made my tool for removing the fuel pumps - https://www.jaguarforums.com/forum/s...-pumps-130587/ - I found that I needed to use a silicon lubricant on the thread or the rings 'bound' while tightening and didn't screw down smoothly and evenly.

 

Roger, thanks for the tip I will ask the mechanics that worked on it if they did

 

A bit more detail might be helpful.