Wynn's coolant system flush

[Simon Jones]

The trouble with flushing into the bleed pipe is that it's at the top of the system so it's not back-flushing at all. Ideally, you need to feed water in at several different points while letting out of different points too so you give everything a real good stirring. I knocked up this crude device so I could remove and block the bottom rad hose and then connect a hose pipe to the outlet on the rad and force clean water up and out the rad cap, expansion tank, and bleed pipe in turn.

It's just an old pipe with a hose fitting glue-gunned into the end. Not pretty but does the job.

[cmm303]

It's competition time for the most bodged radiator/hosepipe adaptor

The glue-free approach, but more components than Simon's so less reliable! For £1.09 on a 21.5-32mm adaptor from screwfix, some gash overflow pipe and hose tap thingy you could have this:





Admission There's a bit of tape around the reducer which is sloppy in an old pipe

On a more serious note.... when flushing you want to avoid pushing crud through narrow (easily blocked) galleys in the engine. I figure the most likely place for this to collect is in the radiator and heater matrixes (should that be matrices?) so I would flush these individually in isolation. You will also need to take a rear heater hose off to get as much old coolant out of the system as a lot sits in the runs to the back and engine. (I had every hose off, the pump and thermostat and reckon there was still 1-2 litres (10%+ of full capacity)