HST intermittent reverse

[SpeedyE420]

I have a B2910hsd that I have recently gone thru everything but hst unit. Everything worked correctly before rebuild and shortly after. However now I am having an issue where reverse only works directly after starting tractor. I can drive it around all I want forward but can’t get reverse to work for anything. But if I turn it off and start it right back up reverse works fine until I go forward again. Anyone have any idea what the issue may be?

 

[mikester]

I have the same problem...my tractor wont go forward or reverse until after I start the engine.

On the more serious side is your HST mechanical or drive by wire? If drive by wire, I'd start by checking and cleaning all your wiring harness connections from the pedal to the servo.

 

[SpeedyE420]

I have the same problem...my tractor wont go forward or reverse until after I start the engine.

On the more serious side is your HST mechanical or drive by wire? If drive by wire, I'd start by checking and cleaning all your wiring harness connections from the pedal to the servo.

It’s mechanical. Think I have narrowed it down to the reverse high pressure check valve. Just going to go ahead and pull it back apart and get into the HST and make sure there isnt anything else internally going on before it gets any worse.

 

[Russell King]

I would verify that the linkage is providing the proper movement (input to HST) before tearing it apart.

 

[ruger1980]

If the linkage and shaft is moving freely and completely I would remove the forward and reverse check, high pressure relief valve, inspect the valve ass'y and seat inside the housing and swap them.