Radiator small bore connection snapped

[moony]

I recently snapped off the small bore hose connection on top of the main rad, that goes to the exp tank. Can anyone tell me whether this is needed or can i just cap it off. many thanks

[Lee]

You definately need it I'm afraid. The cap on the expansion tank is the pressure relief valve and the expansion tank ensures that water will always reach critical parts of the engine if hot or cold.

Don't isolate the expansion tank!! At best I think you would start popping hoses, burst the rad and at worst the head will warp. The expansion tank is more than a convenient place to top up with water.

[porkkis]

You need it.

[moony]

Thanks for your replies. I thought the expansion of the water would track back up the way it entered the cooling system. i will have to bond the connection back on to the radiator. many thanks again

[jameswkr]

Good Luck ! I had this on an older Audi....forget it and fit a new rad...