There is always air in the radiator

[rcb610]

No matter how many times I bleed the radiator, after a few trips it will need bleeding again. I normally just take excess coolant from the header tank and put it into the swirl pot whilst bleeding, so it doesn't really loose any coolant, just bungs it into the header tank.
How does air keep getting into the radiator? Surely you bleed once and that should be it, then just keep an eye on the level in the header tank.

[greenv8s]

If you get any air in the system it will get carried around with the water until it is separated out. The swirl tank is supposed to separate the air out, but it doesn't do a perfect job. Any air that does get past the swirl tank will collect in the radiator and stay there until you bleed the radiator. If you are getting a consistent amount of air in the system each time you run the engine, I would suspect you have a leak allowing air in as the system cools down. A leaky pressure cap would be my first suspect.

[rcb610]

Thanks...I have replaced it once before, but maybe I will replace it again.

[Incorrigible]

The leak in the pressure cap will only be a problem, if there isn't enough coolant in the expansion bottle, won't it