Using water?

[MikeyT]

Doing the usual weekly checks and unscrewed the blue top on the expansion tank by the fans. Filled it with a water/antifreeze mix, perhaps *a touch* too full, (inch from the top) and then ran the car on idle til the fans came on just to check their operation. As soon as the fans came on, water started to drip out from the blue top on the expansion tank.

Now, did it come out because I filled it a bit too full on this occasion (not enough space in system for extra volume of water so finds weakest point, I think?) or should this usually happen at the temperature the fans come on (92?). Presumably if the former, then water eminating from the blue top is OK as that's the overflow? Can't think that's right tho'. This blue lid is EXTREMELY tight I might add (can't do it up any tighter at all).

Cheers for any help.

>>> Edited by MikeyT on Sunday 14th April 21:09

[zippy500]

Id say you put too much in. Suck a bit out with a tube, say another 2 inches and re run your experiment to check.

[duncan m]

Believe that the ali pot should be filled so that the water is 2" below the top, so seems likely that if you over filled it, once up to temp the some will be expelled.

[Marshy]

I've been told 3/4 full for the expansion tank at the front. Which is probably the same as 2" from the top, come to think of it.

[Ford Prefect]

Just had a look in the handbook for my Chim 450 and it says to half fill the expansion tank. Also a dealer told me to fill the tank up to the level of the weld/join halfway up the tank. Suspect your problem is too much pressure finding the weakest point in the system....the filler cap.

John.

[GarryM]

The filler cap is designed to let any excess "drip out" so the water/coolant will find its own level. Nothing to worry about at all (might leave a small water stain on your nice polished expansion tank though!)

[.mark]

Mikey I too had this problem - I seemed to be constantly topping up the expansion tank. Had a word with the dealer who said the book is wrong!
You should fill the swirl pot up to the top and not worry too much about the expansion tank, about an inch in the bottom. I've been doing this for a couple of weeks now and everything seems fine.

[Green&Mean]

I always check the level in the swill tank. I thought the expansion tank, was just that - for expansion, and should'nt hold any liquid when cold ?
My temp runs fine.
Perhaps Steve can enlighten us all ? please.

[shpub]

The answer is.... there is no real straightforward answer. I think the escaping fluid is from overfilling but it really is a question of knowing what the right level is for your car. There are sveral different cooling pipe arrangements which will have different capacities and cause different levels in the expansion pot. What might be mid tank for one might be 2 inches from the top in another and so on.

So the best advice is get to know what the right level is for your car. If you need to keep topping up to that level, there is a leak somewhere.

Steve
www.tvrbooks.co.uk

[cmdar]

quote:
Just had a look in the handbook for my Chim 450 and it says to half fill the expansion tank. Also a dealer told me to fill the tank up to the level of the weld/join halfway up the tank.

That's exactly the advice I was given from my dealer for my Chim 450.

[MikeyT]

Thanks for the help everybody, The level is usually about the half way mark and so I thought I'd been using quite a bit of water instead of throwing it out of the top.

Thanks again.