Corsa-B.uk - Vauxhall, Opel and Holden Corsa B Owners Club

I want to give the radiator and cooling system a flush but I'm not sure the best way to go about it. At the bottom of the radiator (UK driver side) there is a large rubber hose with a smaller hose connected to it in a T junction. Is this the one (the large hose) the one I'm supposed to disconnect? It looks almost impossible to reach the clip (holding the large hose to the radiator) due to its angle, without taking a lot of other stuff out first.

Could I flush the system by disconnecting the hose at the top of the radiator (much easier to access), providing a constant supply of water to the top up tank with a garden hosepipe, and running the engine for a while?

That won't do very much. You can use a flushing agent, some people lob a dishwasher tablet in the header tank, or just flush with fresh water. If the rad is really blocked cheap coke is good for clearing out deposits.

But you really need to get that bottom hose off and reverse flush the rad to have any effect. Have you looked at coming at it from underneath?

As said it's accessible from the underneath the car

You need the bottom hose off so the water is actually flowing through the rad, taking the top hose off is only going to skim any dirt floating at the top

Going from underneath doesn't help that much, due to the angle of the hose clips. What about if I remove the large hose on the other side (passenger side). NOT the expansion tank hose, as was my first idea, the one below it. I know it isn't as far down as the recommended one and therefore won't drain as much crap, but it does take most of the flow and therefore I should be able to shift a lot of stuff out just with the current if the engine is running (I'm not sure if this is the main inlet or outlet to the radiator, if it's the inlet I would stick the garden hose water supply in the hole and allow the water to flush out of the other disconnected tube end).

If you remove the p/s hose you can just remove the stat S pipe and stick the hose straight into the rad and let her rip

I took the two hoses off from the top of the engine and forced the poo out through the engine then through the rad. Worked good enough for me.
Basically it pushed from the entrance to the engine through the rad and back out of the rad where it should of returned back into the engine

That was with a garden hose.. On the advice of two family members that have been mechanics since the 70s