unclefester

Check yours - mine had split, right around the top of it - separated just above the thread. Presume it's not a good thing as that means it's no longer a sealed pressured system.

chrispayze

I don't think the expansion bottle affects the pressurisation. That cap would never hold! It only gives/receives fluid when the radiator cap vents. The pressurised system is 'the other side' of the radiator cap from the bottle.

markforrester99

As far as i know i might be wrong the expansion tank cap is not supposed to hold pressure. The radiator cap pressurises the system and any excess pressure is blown into the expansion tank and then when the radiator cools down it sucks the coolant back into the radiator. Its purely a bottle designed to not let coolant spill out and allow enough room for some excess coolant

unclefester

Aye - that said - i'm sure it shouldn't be open to atmosphere, at least not in the way mine was - i presume age had seen to the plastic.

chrispayze

True, but only for dust and contamination reasons. I doubt very much that is very well sealed even when new, it's mainly to stop splashing, spillage and major contamination. But worth replacing if it's that badly split!

unclefester

Separated almost completely into two parts. I checked it because i thought i was losing a small amount of coolant, probably through evaporation.

richmc

It's only there to keep muck out, as such it's worth replacing whenever. After all Honda only want £12.45 for that piece of plastic!

CynicG

Appreciate it's not pressurised, but I use fluorescent Spoon coolant and if that thing splits and leaks coolant everywhere, it will look like a Predator has been massacred under the bonnet.

I was hoping to replace the whole bottle with something less cheap and plastic, but to date have only found expensive bottle & catch can combos.

richmc

Less cheap are you kidding!? That bottle is almost £86 without the lid and tubes, it's a piece of Tupperware.

V-esi

Cling film and ziptie