I have just drained the coolant out of the rad by taking the cap off and undoing the little white screw plug at the bottom.
After all the coolant had drained into a bucket, I unclipped and pulled the top and bottom hoses off to get any remaining fluid out. Screwed the little white plug back in.
Got the garden hose and put it in the top inlet of the rad and flushed out with clean water out of the bottom outlet.
After about after 5 mins of this, I stopped the water and put everything back together. Hoses back on, top & bottom, cleaned expansion tank and but that back. Filled tank to about half, and started filling the rad back up with Toyota coolant. When I could see the fluid reaching the top of the rad I turned engine on, put heaters on max and waited for the coolant to drop so as I could fill back up.
The gauge on dash got to half way as per normal, but the heaters still blowing cold air!!
I put the rad cap back on as the coolant had started to splutter out of the top. Top hose is to hot to touch and bottom hose is stone cold.
Is this an air lock? and how can I solve this?
Thanks
*after thinking about it, I didn't pour the new coolant in very slowly in to the rad.
**would fitting a 1.3 bar rad cap be any better than the 1.1 I have fitted currently. Just that I have a 1.3 sitting in the garage new.