hydraulic pump belt wear on TK 1600

[cantcutter]

I checked with TK and they said not to use anything less than ISO 32. Said they put 46 in at the factory. I changed the belt and it worked for one day, then the temp dropped again and the belt started burning around the pully again. There is no warming up the fluid by letting it circulate, the belt starts to burn as soon as the engine is started and if you touch any valve it flys off. Pretty much anything under 30 degrees and the mill cannot be operated. Luckily its in the high 60s here this week and I am getting all the sawing I can done.
I thought about a tank heater, but usually don't have power available on location when milling. If I could come up with a mechanical tensioner for the belt that would help some.

[jesse]

I I changed the belt and it worked for one day, then the temp dropped again and the belt started burning around the pully again. There is no warming up the fluid by letting it circulate, the belt starts to burn as soon as the engine is started and if you touch any valve it flys off.

is the belt the right width for the pulley? is the belt slipping on the motor or pump?

[cantcutter]

Yeah the belt is the right one, I realined the pullies already. the belt slips around the pump, I talked to a local hydraulics company and they said that the cold fluid is deadheading the pump because they have it circulating too far out through the energy chain and back, when it should only circulate the few feet through the valve block and back when nothing is in use.

[beenthere]

How far out does it have to go??

Can you put in a diverter or another valve block within the "few feet" to get the oil circulating sooner?

Interesting problem..

[york]

cutter....do you have a test gauge in your system,between pump and the relief valve.....call tech....ask what should relief valve be set at.....no matter what this should be done anyhow,may not be what the matter is,but just for starters...

[cantcutter]

How far out does it have to go??

Can you put in a diverter or another valve block within the "few feet" to get the oil circulating sooner?

Interesting problem..

The mill bed is 17 ft long and the energy chain runs the hydraulics out to the end of the mill and back to the valve block then back to the tank.

I don't have a pressure valve except for the filter, TK said that if it was a checkvalve issue it would by-pass, not deadhead the pump.

I think it is a cold fluid/poor hydraulic design/needs a straight drive pump/ issue. ;)

I choose when I work so I just have to start watching the temperature. I would not loose too many days to cold weather in this part of the country.

[Furby]

Ok, I've been following this thread and I'm wondering if you are indeed correct on your thinking, why don't we hear of more owners with the same problem?
I may be totally wrong here, but I think either your setup is still not right, or you have some other issue inside of the pump, valves or hoses.
Just my thinking, but you are further South than a lot of other owners and I'd think there would be more problems up here than down there if it really was about the fluid.

[cantcutter]

Maybe I got a lemon, or other people are not milling as frequently on cold days as I do. Could be anything; Maybe the day mine was built they where out of some part in the warehouse and they substituted an inferior replacement. Could be that my hydraulics are stiffer than usual because I am not through the break in period yet.

Down side to buying equipment used is that it would cost me money to take it back and have them fix it.

I am not disappointed, they are as much help as they can be without bringing back to them. I just think that the people they have on the phone have too much booklearning and not enough hands on experience. They said that they do not recommend that you operate their mills at lowerthan 10deg. maybe they are just optimistic.

Another thing to consider is that this is a mid-range mill and I am using it for custom milling. When its cold out up north and somebody fires up their 1600 to mill some lumber they probably did not just drag it down the interstate 50 miles in cold weather at 70 mph before doing so.

[Furby]

I agree with most of what you just said. Anything is possible.
Dragging it down the road at 70 mph makes no difference to the fluid temp. Wind chill only works on things that are producing heat at the time.

So let me ask you this, what can you do that you have not already done to eliminate possibilities?
Before making a major change to the manufacture's design (chain drive/direct drive) I'd take the time to drain the system down and start checking things over.
I know it's not easy, but I think it would be the best move.
I'd probly try to send air through the lines to check for blockage.
Is there any chance you got water in the fluid and it did something to the pump or valves while sitting around?
I'm guessing you probly don't have a pump that's close to swap out and try?
Or even a valve/valve bank?

My thinking is, chain drive/direct drive will not solve your problem, just cover it up until it gets even worse.

[beenthere]

I agree with Furby too. I'd be suspicious of the hyd oil, and or the pump.

Right now, the slipping belt is the weak link. You make something else the weak link if you go to a direct drive..and as Furby says...it covers up the problem for awhile.

If you are satisfied with just sawing on warm days, that should work.   

Been an interesting discussion...

[cantcutter]

I agree with most of what you just said. Anything is possible.
Dragging it down the road at 70 mph makes no difference to the fluid temp. Wind chill only works on things that are producing heat at the time.

No, but the temp of the oil in a tank that was run the day before and sitting covered is going to be higher than the one that was uncovered and dragged down the interstate.

Okay: There is really not a whole lot that can be screwed up on this thing. The hydraulics consist of...
1 pump
1 reservor
1 hydraulic motor driving the head
3 5000 lb rams, 2 on the loader and 1 to raise and lower head.
1 filter
1 valve block
and some hoses.

I have already, drained the system down and checked the intake on the tak,  replaced the oil, replaced the belt three times, re-alined the pullies, replaced the filter, took apart and inspected all the hose connections, spoke with Timberking several times, spoke to local hydraulic company.

The pump I was told not to bother testing because if it was bad the hydraulics would not do anything, if it was weak I would know it every time I put the thing under load.

Pretty much I am left with just accepting it for what it is, cold weather and hydraulics.

[ronwood]

Cancutter,

Is there any way that you could route the output of the pump directly pack to the tank bypassing all the hydraulics to see if that makes any difference? It could help you to isolate the problem.

Ron

[Fla._Deadheader]

Never heard of a hydraulic system without a pressure relief valve. THAT would circulate the fluid and mix it with colder oil, and help heat up the system quicker.

[rewimmer]

I assume your mill is under warranty. As I stated before, after 5 hours on the new B-20 I had to shut it down and completely rework everything on my mill. I spoke with TK afterwards and ask them to get a service rep to stop by when one was in my area. Sure enough in a month or so one called and stopped by. Everything checked out ok and he seemed to know what he was doing. You may give him a call.
Jowel Kennedy
870-612-2512
Robert in Virginia

[cantcutter]

Cancutter,

Is there any way that you could route the output of the pump directly pack to the tank bypassing all the hydraulics to see if that makes any difference? It could help you to isolate the problem.

Ron

I thought about doing this, but am not sure about how to go about doing it. The engine and pump is on the carriage and the valve block is on the mill bed. So the hydraulics have to leave the carriage in order to get to the valve block and there for must pass down the energy chain and back to the rear of the mill. It circulates, but what I can see it is circulating into the valve block and then back down the chain and back to the carriage. When you pull one of the valve levers it re-directs the fluid into that application.

I think I can put a three way in at the pump and circulate it right back to the tank until warm, but it will be about a 1 foot loop, not sure that will be enough?

[cantcutter]

I assume your mill is under warranty.

No, I bought it off of the original owner with 12 hours on it, it only had a 1 year warranty and its two years old.

Worth a call though.

[Furby]

Where are the check valves?

[cantcutter]

Where are the check valves?

I don't know? TK says it has a bunch of them, I am guessing that they are in the valve block because they are not inline or near the pump that I can see.

[Furby]

Ok, I'm not a hydraulic expert and willing to admit I don't know all that much about hydraulics.
I've gone over your posts several times looking for a constant timeline for lack of better words.
I'm thinking you have some kind of blockage/partial blockage in your valve system.
When the fluid is warmer, it gets around the blockage easier, but the blockage is still there.
Colder fluid is getting hung up at the blockage.
That's the best idea I can come up with at the moment, sorry if it don't help.

[Bibbyman]

I'm with Furby on the hydraulic knowledge curve.   I know enough to get someone who knows something to help me. 

But about the blockage idea...  One thing the hydraulic guy that built the power unit for me really stressed was to never use Teflon tape to seal threads on hydraulic connections.  He said to use a paste.   The reason being, a small piece of tape could get into the oil and find it's way into a valve or some other part and mess it up.

I mention this because I think you said you took some things apart.  Maybe you (or someone before you) used Teflon tape to seal the threads on the connections.



Here is a picture of our pump unit.  Above the pump is some kind of bypass valve the builder insisted be installed.  It'll dump excess oil back into the tank.

[cantcutter]

All the fittings are flare hydraulic connections, no tape or dope. Could be a blockage, I wouldn't even know where to start looking for it. Can eliminate the hoses because it would push through to the nearest fitting and stop there.

[Gary_C]

I think you may just have a lot of small things that are causing your problems.

First you might replace the pulleys on the belt drive. You could just have one that was machined wrong or the groove could be worn or polished too smooth from excessive slipping. The belt should not bottom in the groove as the sides of the V should do the pulling, not the bottom.

I agree, a chain drive should not be used for a hydraulic pump. Belt drives are tolerable but you have to keep the belt very tight and that is hard on the bearings and seals because of the side loading. Direct drive would be best.

If you did change the hydraulic oil, I hope you did use the ISO 32 rather than ISO 46. If it was me, I would even go to the Woodmizer recommended hydraulic oil which is an Exxon Univis J26 which is a multi-viscosity oil that can be used in any hydraulic system at temperatures from -20 deg F to 100 deg F . After all the hydraulic components in all mills are essentially the same.

If indeed the relief valve is located some distance from the pump, that too is a problem in cold weather. But before I would start changing things, I would check the setting on the relief valve.

So first check the pulleys for wear, then change the hydraulic fluid, then check the relief valve setting.

[flip]

Who have you been speaking with there?  The only person I will deal with as far as technical problems is Mike Anderson, he knows his stuff.

[cantcutter]

Thanks for the input Gary, I hate to change the fluid again, but I can save what I drain for summer I guess. The pullies look good to me, but changing them is cheap. I like the direct drive idea and was thinking that a chain would be second best, but I can see your point about the bearings. The direct drive coupler will cause me to have to loose the electric cluch for the band though.

Flip

Mike is who I have spoken with and I thought that he is less than knowlegable on hydraulics.  Maybe its just that my warrenty is up so they don't want to be bothered, but until I brought in the third party hydraulic guy, Mike was completely unknowing as to where to start. In our first converstaion his closing statement was that "it sounds like something bad is wrong".

[flip]

It sounds like you are to the point that much of this thread has turned into speculation.  My two cents is that you go out and by a high pressure hydraulic guage and several feet of hose and some adapters.  You need to either start checking pressures or have someone that knows hyd. do it for you.  I'm sure TK can provide specs. as to what pressures you need to have at certain points, I thinks some are even in the owners manual if you have that.  I understand the temp. causes some viscosity issues but I think that could be masking your root problem.  Time to throw the guages on and get some specs.