Hello all, I'm new here but have benefited a great deal in the past from the information found here. I have a SK50 sr3 (ser#PJ04-03544) which I purchased from our local dealer brand new in 2005. It now has 5700 hours on it and has been extremely reliable until now and the dealership has closed it's doors. The right travel motor slowly became weak to the point it was difficult to travel, but still could crawl up most anything. Before it got worse I decided to bring it into the shop and check it out. Using the Shop Manual's trouble shooting guide I determined it was either the Pilot travel valve or the right travel control valve. Checking the pilot valve I found it corroded and sticky so I replaced it with no change. I then checked the travel spool on the Control Valve and it appeared to be flawless so I replaced the entire valve thinking the problem was in the housing. The problem got worse, the motor would only bump as if it was going to move. It would rotate about 4". Pressure checks have the following results: P1 & P2 Pressures at 3400 psi P3 at 3800 psi and the P4 (pilot system) at 510 psi. These were taken with the fluid at operating temp and the engine rpm at 2000. To me all looked good in the primary circuits. The secondary (that being from pilot valve to control valve and then to motor) are not so good. Secondary pilot pressure from travel pilot to control valve is 500 psi in reverse but the spool seems not to move. In forward the pilot pressure begins to rise then drops back to zero about the same time time motor stops rotating. So it seems that either the pilot pressure is bypassing or the control valve is either jammed or bypassing. Or maybe the conflux valve is malfunctioning. By the way I resealed the swivel joint because it could have been bypassing main pump flow there. But the swivel joint showed no signs of bypassing but was nearly at its end of life. Currently the right travel motor is new so is the swivel joint, the pilot travel and control valves are new. The work shop manual does not iterate a procedure for diagnosing the conlfux/travel straight valve. I'm at a loss as to how to verify the travel straight function has nothing to do with my issue. Do any of you seasoned experts have any suggestions
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