Honestly, I am just tossing out a possible idea. Hydraulic vales do funny things when they do not operate as intended. As far as cost, that should not matter. If I'm right, I'm sure you'll wanna have it repaired regardless.
2010 Cedar Creek 5th Wheel 34SATS "The Beast"
2006 Ford F350 Lariat 6.0L Diesel
2003 Harley Heritage Softail "Hogzilla"
1986 Marriage to "Wifey" (patience of a saint)