Radiator Drain Tap

[myoldjalopy]

Hello peeps,
My SII radiator drain tap is, of course, completely seized up but I would like to free it up, if I can. Has anyone here had any success in freeing up the drain tap? I see a danger of pulling the fitting out of the rad in the process, or some other damage, and I really don't want to do that.
Thanks.

[ManyMinors]

A good quality penetrating oil for a start? A bit of heat might help too - but don't overdo it. If possible I would remove the radiator first to get better access - although I realise that you'll have to drain the radiator first in order to do this! I tend to remove the bottom hose to drain the radiator and try to catch what coolant I can in a large bowl. On a Series 11, you might also be able to remove the heater hose on the other side?

[myoldjalopy]

Yes, thank you, that's kind of the lines I was thinking of. I, too, usually pull the bottom hose to drain the system but it is a bit messy as you can't catch all that gushes out. I was thinking of taking the rad out anyway as the fan guard has come off and needs soldering back on (I assume it is soldered?).
Of course, even if I can get the tap to move, it may be blocked with 68 years worth of crud

[JOWETTJAVELIN]

Tap needs to come off to clean it properly, yes it will almost certainly be blocked with silt, radiator bottom tank can then be cleaned out. Re-fill with SOFT water and antifreeze.