Hello, I have a Hitachi Zaxis 140W -3 with an intermittent travel issue, When the hydraulic oil is below 65°c everything is fine, above 65°c when travelling if the blade lever is moved the travel will come to an instant stop. The machine also won’t travel in forward at hydraulic oil temps above 65°c but as soon as it cools a degree or two it works fine,There is 350 bar being pumped by the hydraulic pump when the machine is trying to move forward but the wheels make no attempt to move. Any help would be appreciated.
From looking at the hydraulic circuit you may an issue with the pilot pressure that is supplied for the park brake and clutch control of the travel motor via the transmission control valve. There is a solenoid bank used for the operation of the outriggers when fitted which along with the pressure signals for the blade function , all run through the center joint so it may be possible that the pilot signal to the transmission control valve is being lost through the center joint and possibly crossing into the blade control port, but I'm only guessing that this could be an issue. Best regards
Thank you for your help, I will install new center joint seals and keep you updated.
Replaced the center joint seals with Original Hitachi seals, seems to have solved the problem, Thank You for your help , saved me a lot of unnecessary work.