Dash light "drain water separator" came on & then off after draining the collection tank. It came on again so I changed the fuel filters per recommendations of two shops and one being Ford. I happened again, I took it in and after pulling the cab off and taking apart the fuel system they claim there was rust in the fuel lines caused by "bad gas" and denied the warranty with almost a $10,000 bill to fix it. They told me if I didn't fix it to their specifications (replace the whole system) I had to sign a waver that would cancel my remaining warranty. Apparently their fuel filter system does not work otherwise the fuel system could not be contaminated. The shop would not disclose any information submitted to Ford nor any information Ford submitted back regarding the denial. I was told "it's confidential" information. Ford denied some kind of assistance they provide on a case by case basis but I was not allowed to know what the criteria was for assistance. I have maintenance records of the fuel filter maintenance but these were never asked for. Apparently Ford does this on a regular basis after doing internet searches and speaking with other local Ford shops. They know there is a problem but refuse to acknowledge it. How can anyone afford to own a vehicle with these kind of repair bills? The average person can't. I am currently looking into legal action.