Valmet 546 960 head

[Drew78]

I was hopping for some help. I am a Valmet 546 with a 960 head. The roller wheels won't move. All other head functions seem to work. I have power to the wheels and both motors check out. It acts like the oil slams into a brick wall. I think it is in the valve bank by the cab but I am looking for suggestions. I have placed calls to mechanics but it has been successful. Thanks for your time and any ideas.

[hacknchop]

Welcome to the forum I cant help with your problem but im sure someone will as I have read some of the threads dealing with the same types of problems.So hang in there and check back and if you get it figured out on your own get back to us with what the solution was thanks.

[Gary_C]

Your problem is most likely in the valve block right in the head, not on the machine itself. It could be the electrical signal is not getting to the solenoid (wiring problem), it could be the solenoid has failed, or it could be the pilot valve has failed or stuck. Look to see where the hose manifold for the feed roll motors comes out of the valve block and find the double solenoid mounted on top of the valve block. If I remember right there are small pilot lights on the solenoids which will tell you if the signal is getting through. But be careful when running that head and standing near it.

I had a machine exactly like yours but its been some years since I've run it. You really need the manuals for that head and machine to diagnose problems. Put your location in your profile so we can tell if help is nearby. I still have all the manuals and even the old machine at home but right now I am away on a job and will not be home till next week. I've got a large supply of spare parts too.

[Drew78]

Thanks for the info. I do have a service manual. Valves seemed ok. I have power to the head. Odd thing is when I pull the electric off of the feed wheels the problem is the same. That is why I thought it might be in the banks by the cab. I thought maybe some other system was over ridding the wheels. I would be interested in spare parts I am sure I will need them. Thanks

[Gary_C]

Odd thing is when I pull the electric off of the feed wheels the problem is the same. That is why I thought it might be in the banks by the cab. I thought maybe some other system was over ridding the wheels.

I'm not sure why you think that's odd that the wheels do not turn when you disconnect the electrical feeds?

I've got a complete working 960 head along with some spare parts.

Talk to the service people at Rolland in Escanaba for more help.

[Drew78]

The odd part was that it did the same thing. There is power out to the head and both the sides work. Called Rollands several times but didn't get much for answers I guess I can keep calling until I get the right person.

[snowstorm]

call harvey the valmet field rep. he is in the lake states. shuttle valves if you dont know what they are you will running a 546. i have a 546 i dont use it anymore. they used rexroth load sensing pressure compensated valves but with a open center gear pump. it also has a combiner valve that combines the oil from bolth sections of the pump. there is a shuttle in each valve section on the carrier. its just a small peice with 2 o rings and backup washers. when a oring goes missing all kinds of strange things happen

[Drew78]

Just want to say thanks for your help. I found the problem. It was a small o ring behind the the direction control. About a ten cent fix. If you dont count the down time.