while driving my wifes car today(96 fiat cinquecento) temp guage went
thru the roof all of a sudden, pulled in straightaway and opened
bonnet, steam etc, like a cow lookin over a wall so used breakdown
assist(covered by insurance), only waitin for bout 30 mins, guy took
quick look and showed me that the hose had come free from rad, told me
this caused coolant to leak and rad not to kick in? reconnected hose,
filled up with water, pressed a few other hoses then started car, after

few mins told me everything was ok and all i needed to do was add some
coolant when i got a chance?  heres my question, do i need to empty
coolant reservoir and then add new coolant or can i just top up with
coolant? was so happy to get goin so quickly didnt think to ask the
very nice man that came out to me!!!!

tia