radiator mystery

[damobussi]

hi thought my sons vt had a radiator leak checked it out and found water was coming from overflow bottle took it out cause i thought that might have a leak no leak so left it out as the son wasnt driving his car for a couple of days since last saturday 9-1-10 and then to my surprise noticed water coming out of the overflow hose that goes from radiator to overflow bottle this was with the engine cold and not started for two days i know its been 43 degrees today in melbourne but how can the water bypass the radiator cap anyone else had this problem with their vt

[Dayvo]

Maybe the radiator cap is stuffed. Have a look at the seal

[pablo]

Water expands when heated up (even by one degC). Water is not compressible! There is 12 liters of water in the sealed system, so when it heats up and expands (even on a hot day) it has to escape somewhere, so its out of the radiator cap into the overflow pipe, as it's designed to do.
When the water pressure reaches the 'blow off' pre determined pressure of the cap spring, it releases water, otherwise it will split the core or pop a hose.

[banga]

like the guy above said , check the radiaor cap if the rubber is all cracked get another one