Checking the blower seals is pretty simple take the air filter and intake horn off and look down into the vanes, they should be clean and not pitted or scratched and overall the intake to the blower should not be oily and dirty. It is my understanding that the rack tubes would probably be the culprit as the blower seals failing will end up coming out of your spitter tubes and not pooling. Clean the motor real well and then watch the rack tubes ( they are the little hoses with clamps that run from the blower to the block on either side of the blower) for leaks