I put an additional clamp on and its still dripping. I haven't even driven the car in over 4 months and its still dripping. This strikes me as weird because its an upper hose and I don't see how there would be any pressure in the system given how long that car has sat. Going by this diagram, I believe its #1? Its the left most tube section when looking at the front of the car and its leaking at the end where it connects to a metal tube (I assume the radiator) all over the dipstick tube and the alternator.



Could anyone advise me on which part is the correct part to buy? Or maybe something I can do to make the old hose work?

Thanks.

 

Most likely it is the radiator, not the hose.

 

Where the hose connects to the radiator can sometimes crack as the plastic becomes brittle with age...or more often...an screw type hose clamp has been used and over tightened....
You can try a new hose...maybe a pin-hole sized leak in the rubber...hoses are down right cheap....go OEM or find aftermarket at rockauto.com for about $11-15 for the upper hose....the radiator is more like $100 aftermarket....
And the reason why it leaks....the high point (not by much) is the tank up by the firewall...have an opening ANYWHERE BELOW THAT....and the weight of the fluid above it will push out what is in the hole till it reaches that level....higher psi just makes it worse....

 

One tip...
Is the hose WET...
You might need to look at the WATERPUMP....the seal might be failing...causing the drip...
You just need to look around...nobody here can find it for you....

 

Yes I have noticed they are super cheap, I found one on ECS for $6

Its leaking right where the hose meets the radiator tube. You can see in the pictures where I put a piece of paper towel to keep track of how much it was leaking. The second pic is to show the wetness on the dipstick tube and alternator.

 

Suggestion: Get the car very hot, park in a very dark spot at night; keep motor running; open the bonnet; take a strong flashlight and look for a faint spray leak.

 

Good idea

 

Sometimes, the clamp can lose strength over time, allowing antifreeze to leak, then it will build up a deposit, making it impossible to seal perfectly. If you have to remove the hose, check the metal tube to see if there's any deposit, if there is, clean it with a steel brush and install a new clamp. If the tube is corroded and looks like the picture below (for reference, as it's not a Mini part), then you might be looking at a radiator.

 

However, the neck on MINI radiators are made of plastic, not metal.

 

Video of my Mini when the alternator was going bad, as I didn't had any pictures of that area. You can see the metal part where the hose start in the still. That is, unless there's a difference between years and models (base and S).