flushing the cooling system

[highway star]

i'm in the process of replacing the radiator and thought it would be a good opportunity to flush the cooling system. it says in the haynes manual to unscrew the cylinder block drain tap but doesn't say where it is. can anyone describe where it is? the only thing i can find is at the back of the engine on the cylinder head where the heater pipes connect. is this it?

 

[Huw]

Hiya. It's on the other side if the engine( exhaust manifold side ) about half way and a bit up the block toward the gearbox. It's a square headed plug about 3/4" I think. ****** to undo and that's with the engine out of the car. Personally I wouldn't bother and just use a hose to flush all the **** out IMO.! When I rebuilt my engine I did remove it but it was blocked anyway.

Huw

 

[andrew muir]

Yep near rear of block, on exhaust side and very difficult to undo, not worth it as so little fluid comes out, just flush using the thermostat housing.