Coolant leaks and expansion tanks

[Ian and Lins]

Yay fixed it. Been looking for coolant leak for ages. Yep, I know you should work systematically but finally found the problem. Twas the pressurised coolant expansion tank. It had more splits in it around the seams than a Thai Lady Boy. So definitely worth a look if you have such a problem; pretty easy to take off and replace (got a replacement from Just Campers) just remember to put a squirt of washing up liquid around input/output spouts to ease on the flexible pipes.

[tonytech]

Sorry to bear bad news, but I had a brand new JK expansion tank that leaked from the seam.
VW sell a much better tank, just a few £ dearer....

T

[Ian and Lins]

Thanks for that Tony. Will keep an eye on it. If its OK or NOT I will let everyone else know as well. This sort of advice really helps us all. Cheers mate

[kervinmervin]

That's bizzare, just encountered the same and logged on to checkout info. Got back 10 mins ago from trip, saw what I thought was smoke from the vents, rushed to back to see coolant spilling out, I think it's from expansion tank but leak stopped as it cooled, so was hard to tell I assume, pressure makes worse? Will get tank ordered, already got hose as that looks old!

[Ian and Lins]

Yeah its an expansion tank but also has coolant level register, so there will be a 'safe' (don't quote me) level of coolant in the whole system. My expansion tank was leaking at the seams but keeping in coolant below the seams; anything above and it was leaking or pissing out if that is the technical term. So you can keep going but it needs fixing.

[tonytech]

If the tank is leaking, even if the level doesnt drop much below the seam the system wont be pressurised, so cooling will be comprimised. coolant will boil off......
T

[Ian and Lins]

Yep, Listen to that man T. Loss of coolant will terminally kill your engine. KLR250 dead on the hard shoulder of M1 about 1999....must check the coolant level of the 'prili; will do it now, promise.

[R0B]

kevin.check your expansion cap.if its faulty it will fail under pressure.if its the old black one it will probably need replacing anyway.get one from http://www.brickwerks.co.uk/index.php?p ... t&Itemid=6.as some new ones are carp.the brickwerks ones are known to be good...

[kervinmervin]

When I say expansion tank, I think I meant header, the one that is located behind flap. Coolant remains in both, but seemed to be leaking out underneath, looks like it's formed from two sides with seal. Could this be failing under pressure? should this tank be under pressure?

[R0B]

the tank behind the flap is at no time under pressure.if the cap has failed,it will allow coolant to escape into this tank.once the system is pressurised.and this will leak out as the tank becomes full.

[kervinmervin]

Thanks for advice Rob, the cap is a blue VW one, but no idea of the age will look to replace. Will need to take a closer luck tomorrow, it didn't look like the coolant was leaking from the filler cap, but it was hard to see, it felt like the seam at the bottom of this tank but I guess it would run there anyway.

[kervinmervin]

the new cap seems to have solved it, no overflowing today - phew, thanks for help

[R0B]