Just info hopefully it will help. There has to be an access panel to the shower fixtures if they are reached from the back side to be able to unscrew the fittings from the faucet assembly. I have a 2012 x-roads cruiser and the access to my shower fixture are behind a top cabinet door that is to the right as you enter the trailer. My water lines are the pec with the crimped fittings, yours are probably the same. If there is no rear access you should be able to remove knobs and get to the fitting that screws onto the faucet assembly from the front and check for leaks there.