Ok I seem to have developed a bad rear washer leak ... when i run the rear washer is just pours out from under the Driver's side rear quarter, the inside is staying dry but I cannot find where the washer line runs under the truck so i can repair or replace the leaking line. any help would be great

 

anyone?

 

Put someone in the seat and crawl under there while they try to wash the windows.
My guess would wrapped up in or taped to the wiring for your tail lights.