Bought a cheap 2004 Ford Fiesta from a relative which has a cracked expansion tank that drips when the engibe gets hot.
I suspect it's been like that for quite awhile and so he would have kept topping it up with neat water/without anti freeze.
Would this mean that the antifreeze level in tge coolant system would now have been weakened/diluted, or would it not be affected as the coolant never gos lower than the pipe and doesnt circulate in the system?
So basically when i change the tank or repair it with epoxy, can i just top up the tank with 50/50 anti freeze, or will i have to change the coolant in the whole system?
Have to buy a hydrometer etc?