valmet 840 forwarder problems

[sshier]

Wondering if anyone has had problems with the hydrostatic drive on a valmet 840 it moves but not right. some times it goes ok for a while then kicks out of drive and I push the neutral button and then the forward or reverse and it will drive for a few feet and either cut out or go painfully slow now it's bogging while running the loader it doesn't matter were I have the speed control knob set it does the same thing. The hydrostat was just rebuilt any help would be appreciated hopefully it's a switch or something seems like maybe a sensor is limiting the hydraulics and maybe the throttle thanks I'll try to get a video tomorrow

[Jamie_C]

There's an 890 Valmet on our crew, had similar problems with trying to drive and it was electrical  ... the Valmets also seem to be really picky about fuel, try changing your fuel filters, the Valmet goes through about twice as many as the John Deere forwarders. Hopefully it won't turn out to be injector problems, they replaced them all on the 890 last summer after a lot of grief.

[sshier]

You said it was a electrical problem was it the fuel injectors after all

[Stuart Caruk]

IS the drive between the motor and the pump slipping?

[Jamie_C]

Electrical problem caused the hydrostat troubles .... injectors caused the engine being sluggish problems

[sshier]

Oh my well changed every sensor that Roland said and changed fuel filters no change don't know if link is slipping thinking they need to send out a tech or something these things are way to high tech to many hoses and sensors and sensors for sensors

[Jamie_C]

The sensor for the ladder can cause a lot of grief too ... try bypassing it and see what happens.

[sshier]

No ladder on machine just a door sensor

[Jamie_C]

Try bypassing it, i imagine it works the same as the ladder sensor. If it isn't reading the door being closed it will either apply the brakes or not let the brakes release when trying to shift from neutral to forward/reverse. 

Sitting here trying to think what else they did to the 890 on our crew when it acted like that  .... something tells me they also took the spool out of the valve section, check for dirt or tiny pieces of packing from a cylinder.