been to look at a 2000 x reg gs today,looks tidy for its age few jobs to do,its had its ace blanked of,one prob with coolent side when its started the coolen in the header tank diapears,truck on gauge is at norm 1/2 why up,took it for a run for few miles got back went back under bonnet,and coolent eventuly started to fill tank back up,top hose red hot and hard,bottom hose cold,any advise,many thanks