[GMCPaul]

Whoever sold you guys a rubber windshield wiper motor seal has done you a disservice as the rubber seal will quickly dry out crack & shrink from the underhood temps they become subjected to leading them to leak. The wiper motor seals should be a fiberous type seal thats impregnated with a tar like substance as the fiboruos portion is designed to withstand the high temps in the area of the wiper motor and the tar like substance its impregnated with is designed to seal it to the firewall & motor. Those rubber seals generally crack within the 1st year of use leading to air & water leaks.
Paul Jr @ GMCPauls