Anton ..... first thing you can do is to check for leaks from the hoses with the engine running. Have a look for bubbles in the expansion tank with the cap off. Replace the cap. Then,try and squeeze the rubber hoses. If you can't really squeeze them then there's a possiblity the head gaskets on it's way out. A good indication is steam from the exhaust when the engines warm or what looks like cream on the dipstick when you check the oil.
Chris
February 2008