Water/Coolant Header Tank Leak

[clartsonly]

you have already been answered here, I got a pool here too but from a split under the cap, I dont understand what the bubbles are all about it would seem to me that if that is leaking it should only be water, perhaps you have an air lock in the water system, which has built up too much pressure and that sensor went.

my water failures were as follows due to not bleeding the system after changing a seal on the metal pipe.

cap blew - replaced cap
sensor seal blew - replaced sensor seal
tank split - spent ages bleeding the system, replace cap and seal again then noticed a tiny split in the tank, changed tank and bled the system - so far touch wood no more leaks.

[Nicola&Tony]

I put a bit of white plumbers tape, cant remember what its called #. to improve the seal around the threads . . .

PTFE tape . . . I think it's called.

Tony

[foxbase]

Does anybody know the socket size required to fit the large sensor nut? I haven't got any and would like to buy a set that at least contains the nut I require for this particular job.

Also, It's a right awkward place so would you recommend unscrewing the tank from its moutning for better access? Or even taking the header tank cap off?

Finally, I'm a little confused about all this 'bleeding' aspects of the system. I went to unscrew the header tank cap until I found I couldn't take it off as the cap has a pipe that runs directly to the expansion tank. Now, in unscrewing this cap (1/4 of a turn) have I introduced air to the system and caused my leak at the sensor nut? I know nothing about engines (computers are my thing) but I get that the system is presurised and so any tampering (removing of pipes, caps etc - does that require bleeding the air out of the system?

jason @ confused.com

[clartsonly]

use and adjustable spanner on the expansion / header tank. it does not need to be done up too tight. the lower tank is not the expansion tank that is not pressurised you can pull the pipe off the expansion tank cap to fully undo it, and no air will not ruin your system from undoing the cap if the engine is cold.

make sure you top the expansion tank to the top after either replacing the seal or managing to tighten the sensor a little more.

follow the guidelines for bleeding the system, everyone seems to shout about the brickwerks method, which apparently only takes 30 minutes. you may find that the system didn't need bleeding and the fault is purely with not replacing the seal for the sensor when the expansion tank was replaced.

ps computers are my stuff too and have been since 1982, currently wirting j2ee webservices with fop, xslt, and oracle modplsql to create htm and pdf websites.

[foxbase]

Okay, cool I think.

Incidently, silly question perhaps but what coolant to use? My system water is blue coloured if that makes a difference (I know you can get red/pink coloured too).

I haven't got a clue what you wrote about computers. I make video games and rely heavily on an IT dept. LOL! I guess I should of said I'm more into computers than engines!!

[clartsonly]

In my opinion if the water is blue it has already been flushed out / renewed recently, so just top it up with more blue stuff.