Heater bleeding

[LOFTY]

Well i have soft dash classic, and the question is, is there a knack to bleeding heater. I get engine warm and the air comes out hot, but after a couple of minutes it goes cold.
Valve under bonnet is in correct position, pipes feel warm, and even checked cables on side of heater are all working.
So ideas???? :?

[petergalileo]

I had this once, not on a 4x4 but I cured it by warming the engine up and squeezing the top rad hose while the heater is on, dunno, it might work.

[hobbit]

There is a good tool that I saw my friend use, it actually works like the reverse of the pressure testers you can connect to the cooling system on a vehicle, instead of pressurising the system this one actually sucks the air out of an empty system, you listed for any suction from the engine and then, insert a tube into pre-mixed coolant, and it sucks the fluid in and around the system, works a treat

[Range Rover Blues]

I bleed our classic whilst the engine is hot and under pressure to get the remnants out of the heater.