1.8 pushing coolant out through header cap

Hi gents. I've been looking through the the archives to find a solution to my problem, to no avail, and I'm really hoping someone here can help.... I am at the end of my tether!!!!
Had HGF (surprise surprise) on my FL. Got a new head, uprated gasket set, new bolts, water pump, header tank and cap. All went together lovely.
Drove it nice and sensibly for 190 miles when the coolant started being pushed through the header cap. I' re-bled the system, checked the PRV and all is good.
Why is this still happening? Am i missing something obvious? Did i miss something when fitting the new head.
Honestly guys, I know you've heard this before, but please can someone help?

Thanks in advance

washer said:

Hi gents. I've been looking through the the archives to find a solution to my problem, to no avail, and I'm really hoping someone here can help.... I am at the end of my tether!!!!
Had HGF (surprise surprise) on my FL. Got a new head, uprated gasket set, new bolts, water pump, header tank and cap. All went together lovely.
Drove it nice and sensibly for 190 miles when the coolant started being pushed through the header cap. I' re-bled the system, checked the PRV and all is good.
Why is this still happening? Am i missing something obvious? Did i miss something when fitting the new head.
Honestly guys, I know you've heard this before, but please can someone help?

Thanks in advance

Click to expand...

You've answered your own question: :search:, now go and introduce yourself in the Introduce yourself section.

Then burn it!

Sounds like head problem. Dropped liners maybe

Cylinder head was checked and the cracks have not ???can and many possibilities, but be sure first that is not pressure in the cooling system with the engine cold...