That looks like the hose that provides vacuum to the power brakes. (on my 94 Disco I)

 

Bought the hoses along with the coolant hose set. Now the tape just has to hold out, lol.

 

When you get ready to change your radiator hoses, do a search on here, or just shout. The cooling system has to be bled correctly, or you will get air trapped inside. Is isn't hard to bleed, just different.

Might look into downloading a RAVE cd. just google it, you can get one for free...Has the workshop manual on it. Makes things easier..

 

I've got a rave, it has been a great resource. Wish I had known about it when I bought my truck. Thanks for the advice though.