hi i recently added radweld to my radiator which worked fine its just now the temperature goes up and i have to turn the fan on full to keep it at a normal level and i noticed it get worse when it has to work harder i.e up hill??? and im not sure but it sound like the fan is working to hard. please help

 

I would suggest a complete flush of your cooling system to remove that junk you put into it. Then replace the radiator, add antifreeze and bleed the system if needed. Otherwise, you will be replacing the engine soon.