Draining the radiator... and engine block... +?

[badfelafel]

Hi all
This should be an easy one:
Want to change the radiator, so need to drain it.
Doesnt seem to be a tap, but theres a (very rusty) hexagonal bolt underneath near the bottom outlet from the radiator - is that it? Cant quite get near enough to see it tho!

(would it be bad if i just disconnected the radiator without draining it first?)

And do I need to drain the engine block too? The manual helpfully says "theres a drain tap on the side of the engine block". Great! Where?

I think I'd like to flush the engine block, can't I just do this through the radiator inlet / outlet without having to find the tap and drain it first?

Thanks all!

[alex_holden]

It sounds like you've got a plug instead of a drain tap on your radiator. You can just take the bottom pipe off if you want, but water will go all over the place (so don't do it when the water is scalding hot). You don't need to drain the block to change the radiator, but it might be helpful in flushing it. The tap is below the exhaust manifold.

[badfelafel]

Thanks Thats what I wanted to hear!!

[Kevin]

And even if you did have a drain tap they often break when trying to open them so the bottom hose is much easier, if you want to flush through you can use Willies suggestion of putting in some kettle descaler and run it around a little and then drain it out.

[badfelafel]

[Kevin]

As you have the rad out back flush it a couple fo times by putting a hose in the bottom hose outlet with the rad upside down this will move any loose muck.

[badfelafel]

new rad going in - which way should i flush the engine block?

[alex_holden]

The water normally goes in the bottom of the engine and comes out the top hotter than it went in, so back flushing would be putting the water in the top and letting it run through. I normally open the drain cock a doodle diddley and empty the water jacket, then close the cock a doodle diddley and fill the jacket, and repeat until the water that comes out of the cock a doodle diddley is clear. It might be worth also taking the bottom heater pipe off and attaching it to a hosepipe (with the heater valve open) to back-flush the matrix while you're at it.

[alex_holden]

Hmm, it appears the message board doesn't like the name of the thing on the side of the engine that lets the water out...

[badfelafel]

*grin* is there a problem mentioning the drain cock a doodle diddley?

[badfelafel]

*more grins* i knew it would be fun buying a morris! but this isnt what i expected:)

[bmcecosse]

Brave man using wife's tupperware to catch dirty rad water - but you'll learn - the hard way.

[badfelafel]

well spotted - spent longer cleaning the tupperware than it took me to remove the radiator and thermostat!