LT40 Hydraulics

[nas]

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

[bandmiller2]

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.

[ellmoe]

  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

[nas]

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

[Chuck White]

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

[PineNut]

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.

[just_sawing]

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.

[nas]

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?

[Jim H]

      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.

[Magicman]

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.)

[Jim H]

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 >:(

[Magicman]

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..... ;)

[jdtuttle]

Check the voltage output on the alternator. Same thing happened to my LT40.
jim

[nas]

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

[nas]

Anybody ever try a snowplow hydraulic motor for a temporary replacement?

[Chuck White]

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.

[nas]

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

[nas]

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

[jdtuttle]

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

[nas]

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

[Magicman]

Can you go to an electric motor shop, buy larger brushes, and file them down to size?

[WH_Conley]

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.

[MartyParsons]

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  . 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

[isawlogs]

 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.

[WH_Conley]

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.