Pressure in expansion bottle.

[Dom]

Hi, me again!

Just been tweeking and checking the water level after a recent radiator change. I undid the top of the expansion bottle and a fair bit of pressure gushed out, followed by a rush of coolant (couple of inches). The battle was in the usual position, not raised. The engine was luke warm after a run a few hours ago and use on and off all day.

Obviously I'm worried about HGF pressurising the system. Is this usual or shall I take the investigation further? I'm guessing there should be some pressure in the system after a run?

Dom

(sorry about the constant questions on here, but I'm getting there!)

[stag-phil]

Hi Dom

Could be a couple of things before thinking about HGF.

First, the water temperature may have been hotter than you thought.

Second, after the rad replacement ther may have been air left in the system. Do a search on the forum, lots of advice on how to refill the system to avoid air locks. Did you have the heater on full and the left side raised when you refilled the system?

Phil

[Dom]

Thanks Phil,

I was hoping not to have the 'oh dear that should never happen' reply, phew!

The heater was on, although I didnt raise the front.

Maybe it was just a bit warm, I just wasn't sure if these symptoms occur when its hot/warm.

Thanks again.
Dom