The Forestry Forum

General Forestry => Sawmills and Milling => Topic started by: oregonsawer on April 20, 2010, 09:17:08 AM

Title: Hydraulic Problems
Post by: oregonsawer on April 20, 2010, 09:17:08 AM
Having a problem with my LT70 hydraulic system.
One time it works well and then ever thing works really slow.

I have checked the oil levels and added some, Changed the filter.
Still does the same. Now and then the clamp seams to be really jeckey on the shaft it runs
back and forth on.

I know some of you guys can HELP with this problem.

Thank you for this page!
Title: Re: Hydraulic Problems
Post by: Papa1stuff on April 20, 2010, 09:37:44 AM
Have you checked the electrical contacts and the copper strip ,sometimes that gets loose or dirty!
Title: Re: Hydraulic Problems
Post by: ljmathias on April 20, 2010, 10:09:10 AM
My LT40 does the same now and then- doing it  right now and it's the contacts.  I can tell because if I move the saw head around a little, it finally makes good contact and I have the hydraulics back.  Just finished replacing the electronic module for forward and then the fan belt on the generator, so I just want to cut for awhile- fix the contact next week or when it stops altogether; not life threatening problem for  me... ;)

Lj
Title: Re: Hydraulic Problems
Post by: sparks on April 20, 2010, 03:18:35 PM
Take your digital volt meter and put one end on the strip and the other on the contact block. Run the hydraulics and you should have a voltage of less than 1 volt. If more than 1 volt it is a bad connection. Do the same thing on the ground block. One end on the block the other on the rod it touches. More than 1 volt you have a bad connection. If this all checks good you may have a sticking bypass valve on the control body.
Title: Re: Hydraulic Problems
Post by: oregonsawer on April 20, 2010, 06:08:00 PM
Hey sparks I don't have a digital volt meter.
What do you mean by the ground  block and the rod it touches.

This is really strange, If I turn the saw off and let it sit for a wile it works fine
and then it gets really slow and the hydraulic motor sound like it is in a bind and then not one thing will move.

The log turner chain will not turn, and I know that is a different motor.

Thank you for any help.
Title: Re: Hydraulic Problems
Post by: laffs on April 20, 2010, 10:16:14 PM
i dont know about the wood mizer but i assume the pump runs by belt? check the tension
Title: Re: Hydraulic Problems
Post by: backwoods sawyer on April 20, 2010, 11:51:00 PM
That almost sounds like a cavatation issue.
Title: Re: Hydraulic Problems
Post by: sparks on April 21, 2010, 11:12:45 AM
The welded round rod on the lower part of the frame has a block that rides on it all the time. This is the ground for the hydraulics.