Hi Guys
2004 GU
Went over the hill this morning n picked up my car trailer 600Kgs .
Coming back I noticed temp up a bit so I backed off ,sat on 90 .I stopped n had a look noticed rad over flow was down a bit ,
topped it up took about 2.5 litres ,coming over hill had to stop n let it cool .
What could it be ? has twd heavier loads without a drama before .

Please Help
dont want that to happen