Wanted to have the cooling system flushed and filled on my 98 S70 after 44,000 miles.According to service dept. this is not on any routine age/mileage schedule, it is done as needed. I brought the car to Sears to have this done for half the cost but was told they would not do this due to the inside of the hood decal stating only volvo coolant is to be used in the system. It was explained that there are 2 different coolants(green or orange)used in most vehicles but volvo's seems to be nearly clear and the type not able to be determined so to prevent any gelling issues from combining different coolants Sears was reluctant to perform the service. Has anyone done this? Is it absolutely necessary to "go volvo" with this? Would power flushing remove enough original coolant to not have the gel occurance? Would appreciate hearing from anyone who has encounter this situation. Thanks.