Hey Kapiton,
I got your message. I think we may be on different pages with the way we are describing this.
I think we are agreeing that there is no Schrader valve on the rail but the way in which Ford has you check the pressure is by removing that relief valve and install the tool number that is listed in the attachment below.
Or you can do what Roy suggested which is just open the fuel line somewhere else and put in "T" and attach the gauge to it there. General kits from any parts supplier will have what you need to do it this way.
Image (Click to make bigger)
Wednesday, July 28th, 2021 AT 4:46 PM