Can't figure it out????

POSTON WIDEHEAD · April 30, 2011, 09:23:04 PM

My Woodmizer LT 40 HD has a problem. It has 40 hours on it. All the hydraulics work fine, except the hydraulic lift that lifts the logs.
The lift always lifts logs, small and large ones. I have NEVER had a problem lifting. However sometimes the lift does not want to come down, with or without a log on it. I just have to keep moving the hydraulic handle for the lift up and down, up and down, up and down several times until the lift finally decides to go down. I have the right amount of fluid in the pump and have checked everything I know of. And again, I have never had a problem with any of the other hydraulics.

Any ideas?
Thanks guys!
David

Tom · April 30, 2011, 09:28:43 PM

Yes.

If you push down on the handle and the hydraulic motor doesn't run, it's probably a broken or burned switch (spring) That is inside of the end of the valve mechanism, not the centering spring.

I guess it could also be an air bubble, but that is rare with an open system.

D Hagens · May 01, 2011, 01:41:45 AM

I agree with Tom, it could be an air bubble, doubt it but there's a chance that it could be. Is there a bleed screw on your hyd lines?

Bibbyman · May 01, 2011, 04:14:30 AM

Another possibility is...

If you look at the valve body there is (at last on our LT40) a rod running across the top of it with what looks like rocker arms attached. These rocker arms are worked by the levers being pulled up and down. The turning of the rod activates a tiny micro switch at on the right side of the valve body. The micro switch in turn kicks off the solenoid that runs the pump. Now... these little rocker arms are adjustable. And it takes very little for them to be out of adjustment and thus won't trip the micro switch - thus the pump won't kick on - thus no power.

jcbrotz · May 01, 2011, 05:32:59 AM

Listen to Bibbyman, He's always right ;D

Try this, push the arms lower lever if it don't move push/pull any other of the levers. If this makes the arms lower properly then you need to adjust the "arms" on the cam to activate the microswitch.

LOGDOG · May 01, 2011, 09:07:42 AM

My first thought was the rocker arm that Bibby suggested. It's happened to me before.

Magicman · May 01, 2011, 09:23:17 AM

POSTONLT40HD, you did not state whether the hydraulic pump motor was running or not. If it is not running with the lever down, then you have your answer. If the pump motor is running and the loader isn't coming down then it's possible that one of your hydraulic "fuses" is malfunctioning.

As information; If you ever have an severely unbalanced load on the loader, those fuses may also stop the loader from coming down. The fuses are to prevent the loader from dropping if a hydraulic hose burst.

POSTON WIDEHEAD · May 01, 2011, 09:59:13 AM

When I push down on the handle, the pump is not running. This problem only occurs every now and again. I just have to keep pushing the handle up and down and all of a sudden....It works like a brand new one.

Magicman · May 01, 2011, 01:42:56 PM

Then it should be the rocker adjustment that Bibby described.

terrifictimbersllc · May 01, 2011, 08:46:34 PM

Yes it's the rocker, you have to get in the right side of the box with an allen wrench and loosen the rocker for the loader. then push the rocker down tight, and tighten the set screw.

My loader often doesn't go down when it's fully up, not a pump problem, pump is running, have to go up/down quickly a time or two then it goes down. Only at the top of its travel does this happen and it has been that way since new. Not really a problem but wonder what's up with that.

smwwoody · May 01, 2011, 09:56:05 PM

these guys gave you some great info. This place is great for that. Also remember Woodmizer tech support is one of the BEST tech supports going. I have called them with some real dandy problems and they have always came through for me.

Woody

Magicman · May 01, 2011, 10:05:11 PM

Quote from: terrifictimbersllc on May 01, 2011, 08:46:34 PM
pump is running, have to go up/down quickly a time or two then it goes down. Only at the top of its travel does this happen

That could possible be a hydraulic "fuse" problem that I described earlier. Once either of the fuses engage, I have found that only upward travel will release it. I occasionally have to jiggle mine also.

ARKANSAWYER · May 01, 2011, 10:11:12 PM

You can push the back toe roller handle down the same time as the log loader lever and the pump will run so the arms will go down. This will get you by should you be in a job and do not want to stop and repair the lever.
The trick is to adjust the rocker arm while the power is on so if you get it to tight one way or the other the pump will run all the time.

POSTON WIDEHEAD · May 02, 2011, 05:34:49 AM

Thanks Friends! Its 5:25 AM now and I've read all your post dozens of times. As soon as the suns comes up, I'm off to the mill to adjust the rocker arm.
Got a bunch of Long Leaf Pine to mill today.

Has anyone ever just sat down and really wondered where we'd be without the Forestry Forum?

God Bless all ya'll.
David

Bibbyman · May 02, 2011, 07:11:24 AM

Six days a week the Wood-Mizer teck support guys are there. I'm sure they would have work it out with you.

Magicman · May 02, 2011, 08:11:25 AM

Quote from: POSTONLT40HD on May 02, 2011, 05:34:49 AM
I'm off to the mill to adjust the rocker arm.

I can feel your excitement. Yes, you have many caring friends here as well as at WM.

terrifictimbersllc · May 02, 2011, 08:13:53 AM

Get yourself some spare allen keys for those rocker arms. No fun having just one with rounded over ends. McMaster-Carr has them real cheap if your hardware store doesn't have them.

POSTON WIDEHEAD · May 02, 2011, 05:21:10 PM

Yes, yes, yes.....got it fixed! Had allen keys, took the side panel off, made adjustments and BAM....it works everytime!

By the way, yes, I could have used woodmizer tech support. I have used them before on other problems and they walked me right through my problem. They're some GREAT people and my next mill will be a woodmizer if the Lord lets me live long enough.

But listen.......sometimes I like to feel the POWER of the FORUM. I'm hooked!!!!!!!

Thanks Guys!

David

Magicman · May 02, 2011, 07:49:39 PM

Yes, there is "POWER of the FORUM".

Not only did your successful repair/adjustment make your day. It made ours also.

LeeB · May 02, 2011, 11:51:01 PM

Pay attention to what Arky said. You can get it positioned to where it runs all the time. I keep an allen wrench in the hydraulic box. I have to adjust mine all the time. The two plane clamp is where my headache lies.

terrifictimbersllc · May 03, 2011, 05:11:36 AM

I haven't had to adjust rocker arms in a year of sawing, after I replaced the micro switch. It had a little plastic button which gets pressed down by an arm with a roller on it. The plastic button got worn down slowly so more and more rocker arm travel became required to activate the switch.

ARKANSAWYER · May 03, 2011, 07:58:04 AM

If you have to adjust more then one of the rockers in a month or so then that is a micro switch going out. It will work for a spell then you need to adjust one or more of the rockers.
I buy the micro switch from Radio Shack for $2.69 and they last about a year to two years (I saw alot and that was what one from WM would last, for $30) but you need to redrill the holes it mounts to. In a pinch you can use a soldnoid for a old Ford starter if yours burns out on the road and you need a fix quick. The soldnoid from WM works better but when you are down and have work you can get one at about any auto parts place and be up and running.