VR radiator cap/leak

[Gazza2005au]

i have a VR that is leaking coolant out of the top of the bottle on the side my radiator cap says its rated at 135kpa so when i drive the car and turn it off the water in the bottle on the side starts over flowing than every few days depending on how much i drive i have to refill the plastic bottle on the side whats going on here? i have bled the cooling system

[hako]

Try a new cap as it may not be sealing properly - they only cost just over $10. Is your temp gauge indicating "hot" or does it stay normal?

[Gazza2005au]

never goes over half way

[hako]

Then the radiator cap seems the prime candidate....probably the cheapest too. Whats probably happening is that when you turn the hot engine off, the coolant will rapidly get hotter due to 'heat soak' from the stationary hot engine and expands. Normally in this case the radiator cap will hold the coolant under pressure (till it reaches 1.35Kpa) but if faulty the cap will not hold the coolant which may boil (due to reduced pressure) and it goes past the cap and into the overflow bottle at a rapid rate causing it to overflow.
Hope you understand that - composition ain't my best point!

[Gazza2005au]

yep thanks guys totally understand what your saying i just went and checked the cap its a CPC brand