Rad drain

[seb001]

I'm trying to drain the coolant form a 93 Caracan but the drain no longer drains. Only a few drops come out of it. It's the original rad. Can someone confirm that its about 1/2 turn to fully open it (I can't remember)

Two years ago it worked fine. I guess there is a thick layer of deposits at the bottom of the rad.
I was thinking of connecting a hose to the drain and backflushing but it's hard to get access to the drain.

Anu suggestions?

[sandokana]

Turn the drain valve all the way out and don’t forget to remove the radiator cap