had a coolant leak left it in with vauxhall they pressure tested it and found a faulty rad hose they put new one on, problem is i checked coolent level the same day and i checked it today it is down about a inch only done about 4 miles in total, does the coolant have to settle after a change or should i be worried, i topped it up this evening and went for a 15 mile spin and the coolant level never droped, am i worring about nothing.