Hello all,

I will be replacing my third expansion tank in one year! I get a leakage from the nipple (the part looks like screw head) every time. Is there any particular reason for this? How to avoid this issue happening so frequently?

Please see the attached picture for the reference.

Thanks.

 

If it is the nipple, here is a permanent and inexpensive repair for the all too common broken nipple.

https://www.jaguarforums.com/forum/x...t-tank-117188/

 

Thank you for your reply.

I think my reference name was not right. If you see the attached picture, the leak is from the location where plastic screw head connects to the rest of expansion tank.

 

I haven't had that issue at the bleed valve before. Maybe some type of thread sealant would seal up any leaks you have around the threads. I don't know if there is a washer to seal that opening on the threaded "bolt/plug".

 

Yikes, I hope you are not replacing the entire expansion tank because the bleed valve leaks. There is a rubber O ring at the base of the bleed valve head that becomes brittle with age. Replace it with another O ring (you may need to double them up if they are too thin) from any O ring kit from Amazon, Harbor Freight, etc.

 

Hello chillyphilly, Thanks for your reply. I just tightened the bleed valve (plastic screw head) and I will watch if it stays in place. It will be interesting to see why this valve unscrews itself.

The first time changed because of the same issue that NDW linked in the first post- broken nipple. Then the second time, the tank had leaking from the bleed valve where I was unaware that it I can replace the O-ring and ended up replacing the entire expansion tank!

 

A couple of turns of PTFE thread tape may do the trick if it keeps coming undone

 

My old tank used to weep sightly from the bleed nipple.
Sealed it with Loctite 567

It does not matter if you seal it up permanently as you dont need it to bled the system.
Raising the front and running the pumps does the trick

Cheers
34by151