I took my 2nd attempt at flushing my coolant system today. Flushed the rad again and flushed the filler bottle now i know what its for! I was firing water into the filler bottle at pressure and watching the dirt come out of the small overflow pipe into the rad, then once it was clear i flushed the rad again. I then realised that there was loads of water going into the filler bottle but not much coming out the top!

 

I then looked under the car and to my horror saw loads of water pouring out of the underside of the car below the water bottle! I had a feel around and i think its coming out near the top on the neck somewhere. I then thought well I must have just broke it as the car never lost water before. I then thought sod it and filled the system. Started the car and turn the heater on full. I then kept squeezing and refilling till i just got clean water and no air out of the bleed valve on the top of the rad. I let the car run for a good 20min and took my time doing this.

 

I then sealed the rad and turned the heater down a bit, left it running another good 20min and the temp sat at a steady 155F (68c). I then turned it off and sat watching the bottom of the filler bottle. Got a few drips but they were cold (not from the main system) probably just left over spillage.

 

I then tried to pit a bit more water in the filler and it just pissed out again, its reading high on the dip stick thing. By the speed it was coming out I would say that its not a crack and when I put just coolant in it a got just coolant leak out. So has the bottle got an over flow/breather or is it buggered (hole near the top)?

 

I left a cat bowl underneath it so i can see how much it has leaked in the morning.

 

Is the filler bottle pressurised? Any answers please?!

help please! Trying to find out if my car will blow up on the 30mile drive to work tomorrow!

the water will run out of that bottle mate, thats what it is supposed to do

you should really only fill to the top of the rad filler neck

no probs with it as is

there IS a hole in neck of the bottle, dont worry!

Phew!