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Valmet 828 Forwarder, drivetrain problems

Postat: fre 14 jul 2023, 22:10
av GruberChrisi
Good evening, perhaps someone has already encountered a similar issue and can assist me.

I have acquired a Valmet 828 from 1992 that was in need of repairs. Over the past few weeks, I have already addressed the steering, crane, and brakes, making them operational once again.

My current problem relates to the independent driving of the vehicle. It appears that the previous owner made some modifications during the repairs. Has anyone here had experience with the drivetrain system?

In my Valmet 828, there is a switch to toggle between the forward, neutral, and reverse modes. From there, the cables lead to two separate relays and on the right side, to the pump where a valve is located. This valve seems to transmit or process the signal for the hygrostat. I have already replaced the upper cable that leads to the valve. However, accessing the lower cable is extremely challenging, but that is for tomorrow . Next, I plan to remove and examine the valve to determine if it might be faulty.

I hope that someone can provide me with advice and share their experience on this matter.
Thank you in advance

Re: Valmet 828 Forwarder, drivetrain problems

Postat: lör 15 jul 2023, 01:42
av AKKAMAAN
Where in your post can I read what actually is the fault?

Re: Valmet 828 Forwarder, drivetrain problems

Postat: fre 18 aug 2023, 23:19
av GruberChrisi
GruberChrisi skrev:Good evening, perhaps someone has already encountered a similar issue and can assist me.

I have acquired a Valmet 828 from 1992 that was in need of repairs. Over the past few weeks, I have already addressed the steering, crane, and brakes, making them operational once again.

My current problem relates to the independent driving of the vehicle. It appears that the previous owner made some modifications during the repairs. Has anyone here had experience with the drivetrain system?

In my Valmet 828, there is a switch to toggle between the forward, neutral, and reverse modes. From there, the cables lead to two separate relays and on the right side, to the pump where a valve is located. This valve seems to transmit or process the signal for the hygrostat. I have already replaced the upper cable that leads to the valve. However, accessing the lower cable is extremely challenging, but that is for tomorrow . Next, I plan to remove and examine the valve to determine if it might be faulty.

I hope that someone can provide me with advice and share their experience on this matter.
Thank you in advance
Good evening,

I've owned a Valmet 828 for a while now, which was purchased in a heavily repair-needy condition. Over the past few weeks, I've been focusing on the electronics and have replaced all the cables for the drivetrain and relays. During the drivetrain pump control process, I measured a current of 1.3 amps for both forward and reverse movements, that should be allright ?

I'm wondering if anyone has records of the pressure values at the measuring points. When I tilt the cabin, a strip with 6 valves becomes visible, each equipped with 6 pressure ports. Is there a target pressure table available for these ports?

Best regards, Grubi