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General Forestry => Sawmills and Milling => Topic started by: nas on April 09, 2010, 06:25:15 PM

Title: LT40 Hydraulics
Post by: nas on April 09, 2010, 06:25:15 PM
I was milling and my hydraulics started to run slow.  I shut the mill down and tried without the engine running and the motor turned very slow and then quit.  Tried cleaning the ground and still nothing.  If I don't touch it for a few minutes and then try it the motor will turn a few times slowly, then quit again.  What a lousy way to end the week :(  Any suggestions?

Nick
Title: Re: LT40 Hydraulics
Post by: bandmiller2 on April 09, 2010, 08:39:21 PM
How is your battery,and charging system??May be the best thing to check first then all connections and grounds,can't help on the motors never had to work on one.Frank C.
Title: Re: LT40 Hydraulics
Post by: ellmoe on April 09, 2010, 08:43:07 PM
  The hydraulics can be hard on batteries. From my experience I guess that your battery is going bad, if not that, then a charging problem.

Mark
Title: Re: LT40 Hydraulics
Post by: nas on April 09, 2010, 09:38:30 PM
Thanks for the replies.
The mill starts fine, and the other electric motors seem to work fine, so I assume it is not the battery.  I will check it tomorrow.

Nick
Title: Re: LT40 Hydraulics
Post by: Chuck White on April 09, 2010, 09:46:31 PM
Nick
Check the spring-loaded contact that contacts the copper strip when you return the mill back to the front.
If that's not it, maybe check the plastic bolt and the connection on the forward end of the copper strip.

Chuck
Title: Re: LT40 Hydraulics
Post by: PineNut on April 09, 2010, 09:52:59 PM
I am not familiar with Wood-Mizer but expect that the hydraulic pump motor will draw considerably more current than any of the other electrical loads. This means that the hydraulic pump could not work but other electrical loads work OK (for now) So I would not rule out a weak battery. Try a jumper battery and see if that helps. If it does, it could be either a bad battery or problems in the charging system. If not a weak battery, look at all the connections from the battery to the pump motor.
Title: Re: LT40 Hydraulics
Post by: just_sawing on April 10, 2010, 09:18:55 AM
Do you have the Dual Pump as the 70 does. If so check that both pumps are running. If it is a single what you described is faulty brushed if power is to the pump.
I would bypass the power from the WM with a pony battery so I can take out everything but the pump. This can be done by hooking the battery to your soliniod in the case where the line comes off and goes to the strip. and the ground to ground. See how this works. If it doesn't use a screwdriver and go across the two big terminals of the soliniod. If you have faster movement then the soliniold is faulty. If not you are going to need to get the pump rebuilt or replaced. One thing did you check the hyd Level before the trouble shooting. I am in the middle of fixing my 70 with one of my pumps having laid down. I have choosen to replace the pump and I will have the other rebuilt for a spare.
Title: Re: LT40 Hydraulics
Post by: nas on April 10, 2010, 11:43:17 AM
So it looks like I need new brushes for the motor.  Is this a common off the shelf item at hydraulic suppliers or do I need to order one from woodmizer?
Title: Re: LT40 Hydraulics
Post by: Jim H on April 10, 2010, 04:17:57 PM
      Woodmizer  would be the place to get them, if they have them. A couple of years ago they couldn't get any for my '97. I took the motor to a starter/ alternator shop, and they made new brushes and put in new bearings for about the same price as I had been paying for a set of brushes from WM, the downside is you can't carry a spare set with you.
Title: Re: LT40 Hydraulics
Post by: Magicman on April 10, 2010, 06:15:25 PM
I'm really surprised that your trouble was not the copper contact strip or the spring loaded ground contact.  It's really hard to imagine that you would have worn motor brushes on a 2002 model mill.  (I'm just thinking out loud.)
Title: Re: LT40 Hydraulics
Post by: Jim H on April 10, 2010, 09:04:27 PM
Quote from: Magicman on April 10, 2010, 06:15:25 PM
I'm really surprised that your trouble was not the copper contact strip or the spring loaded ground contact.  It's really hard to imagine that you would have worn motor brushes on a 2002 model mill.  (I'm just thinking out loud.)
Woodmizer list the life expectancy of the brushes at 750 hours. The most I ever got out of a set was 1200. I started replacing them around 850 hrs after I shorted out an armature from running them too long >:(
Title: Re: LT40 Hydraulics
Post by: Magicman on April 10, 2010, 09:22:08 PM
My WM Super Hydraulic mill has 5246 hours on it, and the brushes & motors are original.  Maybe the higher HP hydraulic motors (2) make a difference  ???  That's why I was surprised.  I thought they all lasted like that..... ;)
Title: Re: LT40 Hydraulics
Post by: jdtuttle on April 11, 2010, 09:33:34 AM
Check the voltage output on the alternator. Same thing happened to my LT40.
jim
Title: Re: LT40 Hydraulics
Post by: nas on April 11, 2010, 10:53:27 AM
jd, it is definitely the brushes.
MM this is the second set of brushes done on this motor.  The first was at 1100hrs and now it has just over 1900.  I use the hydraulics a fair bit without the engine running, so the hour meter isn't running which might be why there are low engine hours for the brushes.

Nick
Title: Re: LT40 Hydraulics
Post by: nas on April 11, 2010, 06:21:00 PM
Anybody ever try a snowplow hydraulic motor for a temporary replacement?
Title: Re: LT40 Hydraulics
Post by: Chuck White on April 11, 2010, 09:24:50 PM
Quote from: nas on April 11, 2010, 06:21:00 PM
Anybody ever try a snowplow hydraulic motor for a temporary replacement?

Nope!
I haven't tried that, but that's one of the first things I noticed about the hydraulic system, is how much they looked just like a snow-plow motor and pump.

It would probably work.
Title: Re: LT40 Hydraulics
Post by: nas on April 11, 2010, 10:06:56 PM
My uncle is a landscaper and does snow removal in the winter.  He says he has an extra one, so I'm going down there in the morning to look at it.  I'm too busy to be able to wait till Tuesday for the part from Woodmizer.  If it won't my uncle is also the ultimate McGuiver so he can probably find a way to get me going for a couple days till the part gets in.

Nick
Title: Re: LT40 Hydraulics
Post by: nas on April 13, 2010, 01:49:32 PM
so I ended up going to an alternator repair shop and found out they don't make parts for that motor anymore :-[  So I bought a throwaway Chinese knockoff for $175 that got me going.  Called Woodmizer and was told a new motor is $325.  The cheap knockoff has no bearing in the back end, just a bronze bushing, and it runs like a cheap knockoff.  It vibrates and heats up but it works for now.  I will buy a new motor from woodmizer as soon as I can, then keep the knockoff as a backup so I will never need it :)

Nick
Title: Re: LT40 Hydraulics
Post by: jdtuttle on April 13, 2010, 04:21:55 PM
Nick,
I have the 92 LT40 HD and just had my alternator re-built for $105.00. I would check around for another alternator repair shop. I have a spare now because for some reason I go through one every year.
jim
Title: Re: LT40 Hydraulics
Post by: nas on April 13, 2010, 08:38:47 PM
jd
I was told by woodmizer and the alternator shop that this motor was made by Bosch for Monarch hydraulics, and Bosch stopped making it and parts are no longer available.  The new motor woodmizer sells fits on the pump but does not have the same brushes as the old one >:(

Nick
Title: Re: LT40 Hydraulics
Post by: Magicman on April 13, 2010, 08:52:03 PM
Can you go to an electric motor shop, buy larger brushes, and file them down to size?
Title: Re: LT40 Hydraulics
Post by: WH_Conley on December 26, 2010, 06:07:08 PM
To bring this one back up. My hydraulic motor went bad, when I tore it down the armature was wore out, the local alternator shop agreed it was not worth a rebuild. I had him get a replacement motor. The new motor ran slow, no power, would stall out trying to turn a log, even a small one. I took this motor back and ordered a new one from WM. Haven't sawing much lately, but when I put the new motor on it does exactly the same thing that the one from the starter shop did, at twice the money. I went out today and took a battery out of one of my trucks, has always been a hot battery, tested it, even put the charger on it while I made up cables. It is setting on a board under the hydraulic box, I took the cable off the plastic nut and hooked it up to this battery and grounded the battery. Exactly the same results. Anybody got any ideas? I bought the mill in 97 and have never ran into anything like this. I will call tch support tomorrow. Right now I am stumped.
Title: Re: LT40 Hydraulics
Post by: MartyParsons on December 26, 2010, 06:56:12 PM
What kind of hydraulic oil? If you added AW46 it is way to thick. Dextron III will work but it is still thick for winter. WM has a thin hydraulic oil and I change lots of mills over to this. It speeds up the hydraulic pump.
The other thing you might want to check is the ground, there is a brush on the bottom of the rail under the battery box, and if the rail is rusty it will not work well. The New LT35 we had last week made the forward feed chain red hot  :o. We cleaned the paint off the rail and it worked ok the paint had prevented it from grounding.
If you had put in the " hydraulic oil you will need to get it out before adding the thin winter oil. I always pull off the toe board line and catch the oil in a can till the pump gets fast then add the thin oil.
The plastic nut should not be holding the cable on the contact strip, it should be sodered and the plastic bolt holds the strip into the housing and prevents it from moving. You may want to put jumpers right on the solenoid and gound to the motor, with the new Iskra motor there should be a ground wire attached to the end frame and mounted to the mill frame the old motor from Monarch did not have this wire!
Gosh I hope this helps!
Marty
Title: Re: LT40 Hydraulics
Post by: isawlogs on December 26, 2010, 07:19:28 PM
 The first thing I would check is the white ground wire on the solenoide switches that run the hydraulics, I had that come to the point where it only held by a few strands of wire.
Title: Re: LT40 Hydraulics
Post by: WH_Conley on December 26, 2010, 08:39:44 PM
All this mill has ever had put in it was Dexron III, I bought it new. I have sawed in colder weather than this with no problems. As I said I took the cable loose and put it to the hot post on the battery and another cable from the negative post to the mill frame. Bypassing any rub rails or fuses. I did this mainly to eliminate possibilities that something was amiss there. I put the recommended ground wire on like it was illustrated.

Just remembered before in the winter time I usually had torpedo heater that I would point at the hydraulic pump while I was getting ready in the morning.

I have a magnetic heater I will try in the morning, see if it warms up and thins the oil down any. Also I have a new solenoid on the shelf that I will put on, checking all the wires again. That should eliminate everything except the pump and valve body.
Title: Re: LT40 Hydraulics
Post by: jpgreen on December 28, 2010, 12:00:41 AM
You did check the oil level right?  Cause low fluid and a leak will cause your problem every time.
Title: Re: LT40 Hydraulics
Post by: WH_Conley on December 28, 2010, 08:08:46 AM
Changed filter, drained system, put in thinner oil. At the suggestion of a neighbor took apart the by-pass valve and cleaned it. Same thing. The neighbor has a hydraulic shop, supposed to be here this morning with his test equipment.
Title: Re: LT40 Hydraulics
Post by: backwoods sawyer on December 28, 2010, 10:58:04 PM
Check the ground conection on the pump and clean the paint off from under it where the strap bolts to the box.
Title: Re: LT40 Hydraulics
Post by: pnyberg on March 22, 2011, 07:19:20 AM
WH,  did you solve this problem? 

Thanks,
    Peter
Title: Re: LT40 Hydraulics
Post by: Bibbyman on March 22, 2011, 08:08:20 AM
Quote from: Magicman on April 10, 2010, 09:22:08 PM
My WM Super Hydraulic mill has 5246 hours on it, and the brushes & motors are original.  Maybe the higher HP hydraulic motors (2) make a difference  ???  That's why I was surprised.  I thought they all lasted like that..... ;)

The brushes on the first motor on our 2002 Super went out at a bit over 1500 hours.  We had new brushes put in by motor shop.  The brushes in the second motor went out before 2000 hours.  Same thing.  They both lasted about another 500 hours each with the motor shop brushes.  This time the armatures were worn too much to replace the brushes.  That's when we looked at the cost of new motors or to replace them with an external power pack.  We chose to go to a power pack.  Not an option for many people.

I'm not sure what makes the difference between your mill and ours that the motors on your mill are still holding up.  Maybe I "bumped" the valves a lot more.  I suspect starting the motor takes the heaviest toll on the brushes.  Just a guess.
Title: Re: LT40 Hydraulics
Post by: WH_Conley on March 22, 2011, 08:41:47 AM
Yep, replaced the entire pump assembly. Works as good as it ever did. The whole pump and motor cost less than motor by its self. The only thing left was to replace the pump body. That also cost more than the complete package. Anybody need a motor, I have extras.
Title: Re: LT40 Hydraulics
Post by: isawlogs on March 22, 2011, 12:03:48 PM
 What  year is your mill . ???  I'd be interested in the motor ifin it would fit mine.
Title: Re: LT40 Hydraulics
Post by: WH_Conley on March 22, 2011, 04:18:11 PM
97 LT40HD. I have to go back down to the mill later, I will look and see what brand.
Title: Re: LT40 Hydraulics
Post by: isawlogs on March 22, 2011, 05:43:02 PM
Mines a '93 I doubt that it would fit unless it can be retrofitted.
Title: Re: LT40 Hydraulics
Post by: WH_Conley on March 22, 2011, 05:54:09 PM
Monarch is the brand name of the power unit.
Title: Re: LT40 Hydraulics
Post by: isawlogs on March 22, 2011, 05:59:56 PM
 I'll check with WoodMizer and see if that would fit.
Title: Re: LT40 Hydraulics
Post by: woodyone.john on March 25, 2013, 03:05:54 AM
So now my brushes are kaput. '99 40 super twin monarch pumps kiwi $500 + tax +freight each per motor to replace Has anybody done the build/make your own brushes mod yet.I would love to hear about this. our local franchisee says he has some some place but it sounds like hes looking for some one whose real desperate. :P :-X cheers john
Title: Re: LT40 Hydraulics
Post by: Magicman on March 25, 2013, 08:15:40 AM
My local alternator/starter repair shop rebuilt mine.  Bearings, two new brush rack assemblies and an armature that was fried when the brushes failed.
Title: Re: LT40 Hydraulics
Post by: woodyone.john on March 25, 2013, 02:49:03 PM
thanks mm.
Title: Re: LT40 Hydraulics
Post by: JustinW_NZ on March 25, 2013, 10:07:13 PM
Quote from: woodyone.john on March 25, 2013, 03:05:54 AM
So now my brushes are kaput. '99 40 super twin monarch pumps kiwi $500 + tax +freight each per motor to replace Has anybody done the build/make your own brushes mod yet.I would love to hear about this. our local franchisee says he has some some place but it sounds like hes looking for some one whose real desperate. :P :-X cheers john

Bummer, sounds expensive :(

I just pulled my two pumps/motors apart and gave them a BIG clean out.
The brushes were ok, but bearings not so flash, they were a simple off the shelf part if that helps ($7 each from memory)

Would love to know how you get on in case I have to go down the same path :(

Cheers
Justin
Title: Re: LT40 Hydraulics
Post by: woodyone.john on March 26, 2013, 03:59:48 AM
Justin,found some one who can make new brushes to suit.approx$100/motor If they were ordered by the 100 they would be much cheaper.Makes me wonder why WM and or it agencies dont do that and hold them in stock.I will need to solder them to the sub assembly.
Title: Re: LT40 Hydraulics
Post by: terrifictimbersllc on March 26, 2013, 08:15:49 AM
Just had my LT40 Super Monarch (bosch) motors rebuilt last week at the 1500 hours point.  One had brushes all shot, the other, one out of the four brushes was just about gone. For both the repair was  1) new bearings 2) new brushes 3) turn down the armature small diameter which contacts the brushes.  I think if this isn't turned the new brush life will be much shorter than it should be.  Cost was $190 for one at an electric shop and $85 for another at a starter place.  The electric shop didn't have enough brushes to do both so I took the second one to the starter place. He had to order new brushes but got them overnight. They were a bit shorter than those from the electric shop.    Now the motors are running side by side and I get to see who's fix was best.
Title: Re: LT40 Hydraulics
Post by: woodyone.john on March 29, 2013, 12:22:52 AM
New bushes cost $25 including tax. got them made with 6 inch tails. soldered them on to the other tailsafter sleeving them.nowthe whole hydraulic system is together again with new oil,and working well. cheers john
Title: Re: LT40 Hydraulics
Post by: Chuck White on March 29, 2013, 07:22:49 AM
Great to hear that John, happy sawing!  :)
Title: Re: LT40 Hydraulics
Post by: Magicman on March 29, 2013, 07:32:01 AM
Good job John.   smiley_thumbsup  Sometimes we just have to do what we have to do.   :)