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Draining/flushing coolant

rjjv1997

New Member
Aug 22, 2026
1
0
1
Netherlands
Does anyone happen to have experience with completely draining (and/or flushing) the coolant reservoir and cooling system? I've read online that you can't fully drain the entire system using just the radiator drain plug. This will be my first time doing this, so I was wondering if it's realistically doable.

The system currently has the wrong coolant in it and I'm switching to SP14+. I just want to avoid ending up with several litres of demineralised water still trapped in the system after doing a flush/clean, as that would dilute the new coolant.

Any tips or advice would be greatly appreciated. Thanks!
 
Why did mine a couple of months ago. Took about four complete drains of the radiator before I was happy that all the old stuff was out. Basically drain as much as you can from the radiator , top up with a new coolant plus of course distilled water. Run it up to temperature. Then drain and repeat until you're happy it's all gone. .
 
Reassemble the thermostat, then flushing the whole open big circuit with au little pressure from your garden hose.