Golf 1300 radiator bottle

[TylerG]

Hi guys,
That round plastic bottle with the blue cap had two square holes in the side,
I've seen a bit of water/coolant fluid coming out of the bottom square sometimes,
Is this normal? Is it a pressure release valve in there? I can't see into it
Can I plug it with silicone or such?
The car is not overheating, but the fan is coming on before it used to,
Thanks,
Tyler

[Sean Trollope]

Perfectly normal. Or at least I think. Mines always done it when I fill the thing(very seldom)

Sent from my SM-G570F using Tapatalk

[missioner]

Hi guys,
That round plastic bottle with the blue cap had two square holes in the side,
I've seen a bit of water/coolant fluid coming out of the bottom square sometimes,
Is this normal? Is it a pressure release valve in there? I can't see into it
Can I plug it with silicone or such?
The car is not overheating, but the fan is coming on before it used to,
Thanks,
Tyler

Post a picture of your bottle.

Coolant shouldn't leak from the cap or bottle when the car is hot.

Observe the car by taking a short drive to warm it up, stop at a safe location (your house) and let it idle till the fan runs. Look closely at all the coolant pipes to check for leaks. Look also at the intake manifold, it has two little metal plugs on either side that leak. The block has three metal plugs that also rust through under the exhaust manifold, check those. Lastly feel the thin pipe that runs from the radiator to the expansion bottle to see if it is hot along its length.

Post the results here

Oh and more pics the better

[MarshallGTi]

The cap will have a release valve, replace it with a new one, maybe yours has gotten tired and is releasing pressure a bit too early.

[TylerG]

Thanks for the replies guys, it has a new cap and yes, Captain, the small pipe back to the expansion bottle does get hot but I have taken it off and it's not blocked, I have also put a new thermostat in last week, maybe I should just add more antifreeze, it came out the workshop last week so I'm not sure how much they refilled it with, thanks

[panic-mechanic]

if you keep filling it up it will keep letting a little bit out. that level on the bottle that says max is where it should lie. More than that is too much for the system under pressure and the expansion / pressure valve will let it out. It should stop at some point. Don't add water unless it is lower than the min mark in which case you might have a leak somewhere else.