Water supply 'Expansion Tank'

[briankerrys47]

It seems to have a leak from the bottom cannot see without ,removal anyone any links to show what is below!!!,supply hose and exp hose connection are ok but it is bottom of tank I cannot see.

[fenj66]

there plastic and have been known to split. very hard to see unless you can keep engine running at full temp and crawl around untill you can actually see the water escaping.

[amacman]

The level switch fits into the base of the expansion tank . It has a poorly fitting o-ring to seal it .
Item 3 on this link http://www.realoem.com/bmw/showparts.do ... g=17&fg=05

[shadrack]

just put one of these on the 318ci yesterday as it had split, been losing water very slowly, found various little leaks till eventually noticed the bottle had a split down the side,

[briankerrys47]

[quote="amacman"]
The level switch fits into the base of the expansion tank . It has a poorly fitting o-ring to seal it .
Item 3 on this link http://www.realoem.com/bmw/showparts.do ... g=17&fg=05
[/quote]Thanks for reply folks,done the research understand now they are prone to splitting I believe or it maybe 0 ring have contacted Breakers to try and find second hand or yanks are on $70.Anyway can wait till March when back from the 'Med'  just wonder whether it is the same type of 0 ring that they fit to the W/Washer Tank ??? Had a leak on that 2years back but cured it with Silocone  O:-)