I received the following from the transducer manufacture
You may purchase this part from our distribution partner; Digi-Key. They can be located at the following link: http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=1966259;keywords=SSI%20Technologies
I have not followed up on the info.
Every so often my BrakeSmart will not go over 68 psi. A hard reboot ( turn off the 12 volt supply and wait 20 minutes ) has worked so far to restore full function.