A different and simpler method for bleeding cooling system

[airhead]

I had faffed around trying to get all the air out of the vans radiator for over an hour in the past and did succeed so far as I could tell, but I was always thinking to myself "Why the hell is there no filler in the top of the radiator, considering it's the highest point in the system?". In a manner of speaking there is. It's just very small. I had to rebleed the system anyway after replacing the thermostat so I devised this method to make my life easier. I filled up the coolant bottle in the engine bay to begin with, closed that, then removed the bleed screw altogether and used a large syringe-like thing I got to fill the radiator through that hole to the brim. I then opened the coolant bottle and bubbles came up and the fluid level dropped in both the rad and the bottle so I topped them both up again, put the bleed screw back in and tightened it, then ran the auxiliary pump for a while off the battery which purged a bit more air from around the block and then topped up the system another last time. Started the van and drove it and got no signs of overheating. Checked for air and there wasn't a bit. The whole process took maybe 15 minutes and I didn't even have to start the engine and wreck the neighbours heads with the noise. I'm sure in the absence of the syringe thing I had you could make a sort of funnel for it or something along those lines. Use your imaginations on that one.

[California Dreamin]

I'm pleased you found a work around but under normal circumstances you need the engine running to circulate the coolant and push any trapped air to the bleed points and you can't really do that until the thermostat has opened.
A thermostat change involves minor coolant loss, It sounds like you were lucky and didn't have any particular problems getting all the air out...I fear it is a little bit more involved when the system is fully drained.
Filling from the radiator through it's bleed hole is a good idea but that doesn't necessarily mean trapped air will automatically find it's way to that point. The thermostat needs to be open and the coolant circulating in most cases.....

Martin

[airhead]

Duly noted. I think a combination of both methods would be a surefire way of getting it done properly and easily so. So I suppose what you could do is use my method, then run the engine to operating temperature, rev it, hold it revved and fill the coolant bottle, close it, turn off the engine and fill the rad through the bleed screw.

[what2do]

, then ran the auxiliary pump for a while off the battery .[/quote]


I promise I'm not as dumb as some may think - I am, however, a bit jaded after a few sherbets last night, but could smeone explain what this means/involves? Cheers.

[Oldiebut goodie]

Turbo diesels have an additional electric coolant pump that continues to circulate coolant after switch off to allow turbo gubbins to cool down more slowly, basically.

[what2do]

That clears that up then, plus the booze has worn off!