Shineyis200

Hi, I'm new to this forum, I've had my is200 for over a year now, but all of a sudden I'm loosing coolant, I've been looking though loads of threads on here for help. I've got red residue on the top of the water pump next to the bypass pipe, would most people recommend replacing water pump and the o rings on the bypass pipe or just the o rings?? Please be gentle I'm new :-)