2000 chevy blazer 4×4February 19, 2015if the transmission pump goes out do you have to rebuild the transmission. Keywords:Blazertransmission pump 1 thought on “2000 chevy blazer 4×4” Freeautomechanic February 19, 2015 at 1:56 pm No. You only have to replace the pump. But the transmission does have to be removed from the vehicle to replace the pump. This is not the exact transmission diagram from your vehicle but is meant for reference purposes. #7 in diagram refers to the front pump. Comments are closed.