RS74

Over the past few days i,ve noticed after a drive the coolant level in the reserve tank next to radiator rises about an inch over the max mark and there are signs of a few small bubbles in coolant , after a few minutes the level drops down to normal. i,ve changed my rad caps due to one was hissing slightly when pressurised, but still it doe's the same thing when hot (not the hissing but the level rises) is this normal due to the pressure or have i got problems with head gaskets NOTE. drove 300 miles this weekend and never missed a beat or over heated. any help will be a big

dj219957

its normal for the level to rise when the car is hot. that is the purpose of the expansion tank. to let the hot coolant from the rad to expand into it. when the car cools the rad cap is designed to allow the coolant to go back into the radiator. you did the right thing by replacing the cap if the old one was hissing.
small bubbles are not something to worry about either. it could just be a bit of air coming out due to localised boiling in the cooling system. mines done it before and touch wood 12 months on she still runs like a bute. could also be just a bit of air purging its way out after you replaced the faulty cap. i really wouldnt worry bout it.

RS74

cheers buddy just what i wanted to hear , thought it was normal but to be on the safe side i thought i'd ask , thanks again