Service brakes won't dump pressure?

Always compare them. Dealers hate me because when a truck goes into service and there is something odd about the claim from the mechanic, I tell the driver to make sure that on the work order "all parts are to be returned to driver for inspection" and I have them tell the write up dweeb this includes core items if it has to be. I have caught a lot of good parts coming off the truck and tested on another one where we went back to the dealer and complained about it.