Disc brakes locked

What kind of prop valve are you using...an aftermarket adjustable one or a stock style repro? There have been a lot of issues with the stock style repro prop valves. They were machined wrong and lock up the brakes. I don't know if this was ever fixed or if there is still a problem with them.

Push down on the pin that sticks out the top of the valve and see if that relieves the pressure.(if you are using a stock style valve)