Towing Issues: WRECKER BED, valve body, check valve

Question
HEY HOW R U QUICK QUESTION BE 21 FOOT JERR-DAN FLAT BED WON'T GO FORWARD PTO IS OK WHEEL LIFT AND ALL OTHER MOTIONS A STRONG AND OK!ANY CLUEVALVE BODY ALSO PUTTING PRESSURE TO FEED LINE TO PISTON.IM NOT SURE IS THERE ANYTHING ELSO INLINE BEFORE THE SLIDE PISTON AND AFTER VALVEBODY?ANY INFO WILL HELP THANKS OF TO THE HYDROLIC SHOP IF I DONT FIGURE THIS OUT THANKS FOR YOUR HELP....

Answer
Well not real sure, but I think that their might be a check valve in there somewhere..

The most common problems are the valve body units and I am sure if you went to the hydraulic shop already then you have it fixed or at least know what is wrong.

Sorry but that stuff at times confuses the heck out of me...