Cooling System


Club Member
I'm about to flush the cooling system and put in new coolant. Two questions;
1) The thermostat has a small popet on the top flat disc - is there a special way the thermostat needs to oriented? What does the popet actually do?
2) The engine block coolant drain plug - not sure which plug this is - I've attached pic with two possibles...


  • Drain PLug.jpg
    Drain PLug.jpg
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Staff member
Site Administrator
The thermostat needs to be oriented so it doesn't foul when open on the lower housing - should be obvious when you look at 'em. If the popet is what I think it is, then it is to allow some flow when the stat is closed - stops airlocks or sommat.
The block drain is on the other side of the block, below #5 ports or so.


Club Member
at the top of the thermostat housing is a notch mark to align it with. Just done mine as the pipe on top was leaking and corrosion had set in the housing so had to get it ally welded.