# 648 New Holland loose belts



## pettibone (Jul 18, 2015)

Probably a question for Mike 10. Does anyone know if oil can get trapped in the bottom of hydraulic tensioner cylinder and keep it from going down all the way so the belts are loose when empty to the point of not turning? Can't find anything else wrong, makes for a nice soft core. Thanks


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## mike10 (May 29, 2011)

Open and close the tailgate at least one time to get a true reading on the pressure gauge. After closing the tailgate look at the pressure gauge. The gauge should read 0. If there is pressure showing then the system is overcharged. Loosen a fitting at the bottom of the cylinder to bleed the excess oil off. Be careful, the system will have pressure and while it may only be a couple of hundred pounds, the oil will come out in force. Better to loosen the nut slightly and let the oil slowly escape. It is not fun getting an oil bath. Don't ask how I know.


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## pettibone (Jul 18, 2015)

I've opened and closed it several times to see if there was any pressure and was at zero. I thought maybe something could get trapped under the cylinder that would prevent it from going down all the way. This seems like it happened over time as I've tightened the spring a few times and they always seem to loosen. Could the belts strech?


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## 8350HiTech (Jul 26, 2013)

Are they notably loose or just not turning until you get hay in it?


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## pettibone (Jul 18, 2015)

They were tight on the rear of the baler but now you can push them in six inches with no effort at seem loose and floppy. starts a bale okay seems like a little hay tightens them up so it turns. Crappy core though


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## Gearclash (Nov 25, 2010)

If there are no other obvious problems try lubing the pivots of the take up arm, all of them. There is not a lot of spring force left to pull on the take up arm on an empty chamber and it seems that too much stiffness will keep the arm from pulling on the belts hard enough at the very end of the travel.


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## pettibone (Jul 18, 2015)

I've looked at the shaft that goes from one side to the other everything looks good has plastic bushings that it turns on seems like it should turn easily but I could put some oil on and see if it makes any difference.


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## OhioHay (Jun 4, 2008)

Are your belts stretched?. Might be time for new ones.


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## mike10 (May 29, 2011)

Try lubricating the cylinder rods of the tension cylinders. The inner bore of the end gland where the rod goes through can rust and bind the rods from completely retracting.


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## pettibone (Jul 18, 2015)

This is the third season for me with this baler. When I bought it the story was it had new belts, bought it from a dealer in Nova Scotia sight unseen. When I got it had five new belts so I got one to match the jd style belts that were on it. I have no idea where the belts came from but they are in good shape. I was wondering if they could strech. I'll lube up the pin on the ends of the cylinder never gave that a thought


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## 8350HiTech (Jul 26, 2013)

Stretching is unlikely. Do you remember how long of a belt you put on?


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## pettibone (Jul 18, 2015)

I bought a belt from guy in Johnson City TN not sure if we talked about length but I assume it's 343 inches. He knew what it was for so I'm thinking it's right. I took one of the loose belts off and measured it the other day and it was 3421/2 plus the space between where lacing is. Mato lacing


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## 8350HiTech (Jul 26, 2013)

Then you already know they aren't stretched.


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## pettibone (Jul 18, 2015)

Guess I answered my own question.


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## pettibone (Jul 18, 2015)

I wonder if the tension spring could lose strength over time


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## mike10 (May 29, 2011)

How much of the chrome cylinder rod is sticking out. If the belts were stretched the rods should be pulled in close to all the way.

Loosen the tension adjusting knob all the way on the cylinder and see if the rods will pull in farther.

2 to 3" of travel when you push on the back of the belt is normal, 6" is not.

Any binding will be in the cylinder mounts, or the cylinder itself at the top end where the rod slides in and out. While the end of the cylinder has an outer seal it is more a dirt seal then a liquid seal, so it is possible for moisture to migrate into the top gland and cause the gland to rust between the outer dirt seal and the inner oil seal.

.


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## pettibone (Jul 18, 2015)

Just guessing I'd say the rod is sticking out more than two inches I'll have to measure it. Now I wish I looked at that before so I could compare


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## mike10 (May 29, 2011)

Open the tension valve all the way. If the cylinders are not binding the top cylinder mounting pin shoudl be free. If there is still pressure on the pins from the springs pulling the arm down, then the problem is in the cylinders.


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## pettibone (Jul 18, 2015)

Went and got the baler this morning, it's been sitting for a week and a half and here's what I found. Walked around the back of the baler and noticed belts we're tight looked at the rod from tension cylinder was not sticking out as much as it had been. Measured the space between top of cylinder and the gland was 1 inch. Then I noticed had 700lbs pressure on gauge don't know how. Backed off the valve and dumped pressure, now the rod stuck out 1 1/4 inches and belts were looser. Hooked it to tractor and started it opened it up and closed it a few times with no pressure in it then turned it to 1500 open and closed it a few times, now rod sticks out 1 5/8 inches and belts are loose plus I oiled everything. But did notice the lock on that side is bent so had about half an inch space where it should be tight. But that shouldn't effect the belts just give me something else to fix


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## mike10 (May 29, 2011)

The system will build pressure after sitting awhile, this normal and the reason I had you open and close the tailgate one time to get an accurate pressure reading with the tailgate closed. The belts will not be tight when the baler empty and the tailgate closed, but 6" is too loose. Are all belts equally loose?


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## pettibone (Jul 18, 2015)

The outside belts seem to be looser than the other ones. I took one of the outside ones off and measured it and it was right at 343.


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## mike10 (May 29, 2011)

Even if the outside belts have more slack at the back of the baler that may not be the case elsewhere in the baler.

There is only one way to see if the belts are the same length and that is to remove them. To check if the tension cylinders are working properly you will also remove the belts

Raise the tailgate and install the pin under the takeup arm so the tension can be taken off the belts when the tailgate is lowered some. Lock the tailgate before entering the baler. Remove all the belts but one in the center. Cut a piece of belt from one of the old belts about 20 to 24" long and laced on each end. Install this short piece of belt in the one remaining belt in the baler. Open the tailgate until the pin can be removed from under the takeup arm. Lower the tailgate all the way. The tension cylinders should fully retract if there is no binding. Remove the one belt from the baler. Lay all belts out side by side with one end even. Check the other end of the belts to see how close they are in length.


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## pettibone (Jul 18, 2015)

How short could you make the belts before it would effect things. When I got the baler the two belts on the right were looser than the rest,took them off to check the length which was okay but top roll had rubber missing on that side. Then I put on one new one to match up with the others so I know at least 3 are the same. I guess I'm just getting worried because sometime they don't turn when you start the baler which it never did before. I appreciate all the help.


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## pettibone (Jul 18, 2015)

How short could you make the belts before it would effect things. When I got the baler the two belts on the right were looser than the rest,took them off to check the length which was okay but top roll had rubber missing on that side. Then I put on one new one to match up with the others so I know at least 3 are the same. I guess I'm just getting worried because sometime they don't turn when you start the baler which it never did before. I appreciate all the help.


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