2005 S-Type V6 3.0

What is the valve/screw on top of the radiator reservoir. Why is it leaking, did I over fill the reservoir? If it is defective, how can I stop it from leaking? I've tightened it down slightly, but it still leaks. Is there a rubber seal/gasket that is replaceable?

Also, if I have to buy a new reservoir, what is the best after market brand and where can it be purchased from?

thanks in advance

Bryan
Tucson Arizona

 

Here are 2 links to new expansion tanks. The first one OEM.
03 2003 Jaguar S Type Expansion Tank - Cooling System - Eurospares, Genuine, Meyle - PartsGeek

This is a link for tips for replacing it from forum members with some great advice and photos in their discussion.

https://www.jaguarforums.com/forum/s...lacment-52090/

 

It's the bleed screw, I don't know if it has a seal or a seat, It's never been a problem with leaking for me.
I think it comes right out so you could check / clean it and see what's up.
I'd stick with an OEM tank if I had to choose.

 

I was told there is an o ring under that bleed screw.

It also should not be overtightened, just snugged.

 

Wait until the car is cold. Remove the bleeder screw and inspect. There is an O-ring so it might be damaged or missing. Of course you could have a crack in the plastic that makes it look like the bleeder screw is the problem.

You probably know the upper plastic tanks are a known problem area so you might consider changing the entire tank if you plan to keep the car.
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