# hydraulic pressure control



## newholland650 (Apr 20, 2015)

On my 650 nh round baler I replaced the leaking line going from the gauge to the cylinder. My question is that when I raise the gate the gauge never moves so I wonder if its a bad gauge or should it be charged since that line was off. The man that baled with it last year said the bales wasn't as tight as he liked so I need some experienced advice before throwing stuff at it. Thanks in advance


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## newholland650 (Apr 20, 2015)

This is all I get when gate is raised. Also my book says to adjust chain to 1/8 inch sag which this is more but I adjusted where it said to but it didn't help. Does it need a link taken out?


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## rajela (Feb 15, 2014)

If the NH is like a JD the gauge doesn't show pressure until the bale is forming. Not sure if this is gauge is the same as a JD.


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## 8350HiTech (Jul 26, 2013)

rajela said:


> If the NH is like a JD the gauge doesn't show pressure until the bale is forming. Not sure if this is gauge is the same as a JD.


NH gauge will show pressure with the gate up.

I'm guessing you need a gauge. Even if you lost some oil it should move the needle a little.


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## TJH (Mar 23, 2014)

Make sure the system is fully charged first. The ram should move when you operate the hydraulic lever, I do mine with the tail gate half open, tension off the belts. It may take 3 or 4 cycles to fill it up, the gauge isn't all that much but is kinda a pain to get back in cause it won't be the same as what you took out at least mine wasn't. When you fill the system make sure the knob on top of the cylinder is fully open ( counter clockwise then turn it back clockwise to check you pressure, if you don't you won't see any pressure. Stick your finger on the back side of the chain tensioner to see if you have any adjustment left in the slot the bolt goes through, if you don't have any then you will have to take a link out, but check the adjuster first and make sure you get it good and tight or it will loosen up on you.


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## TJH (Mar 23, 2014)

After a second look at your chain it more that likely hasn't ever been adjusted. Loosen the bolt a little and tap the nylon guide up with a hammer and see if it moves. Looking at the picture I do believe you have some adjustment left.


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## 8350HiTech (Jul 26, 2013)

If your chain turns out to need a link removed, throw it in the trash instead. Buy a new chain


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## mike10 (May 29, 2011)

The chain can be a pain to adjust. The square shoulder of the carriage bolt is not in what you usually see, a slot like this ========, but is a slot made like this <><><><> where the shoulder corners of the carriage bolt fit into the corners of the one of the openings. This is to keep the bolt from being pushed forward and the chain loosening. I do not do it, but, you can rotate the bolt so it slides in the slot like what you usually see. With the way the openings are made, you can not fine tune the slack in the chain. Chances are it will either be too tight or too loose. What I do on these older balers is use an idler block from the "8" series balers where the hole in the block is offset and acts as an eccentric. Loosen the bolt and just rotate the block to tighten the chain.

If you had a leak in the tension system, you will need to recharge the system. There is a special fitting behind the gauge you connect a hose from the tractor. If you can not borrow a hose from a dealer, then you can probably do the job without one but a lot more trouble. You can unscrew the hose from the gauge and attach a hose to the tension hose and the tractor. Open the tension adjustment valve completely like TJH said. With the endgate closed use the tractor hydraulics to extend the tension cylinder(s) all the way and then retract the cylinders. Do this three times. On the third time, turn the tractor engine off before retracting the cylinders. Then with the engine off lower the tension cylinders completely allowing enough time for the excess oil to return to the tractor. Remove hose and install gauge. Adjust tension valve. If your baler has a separate oil reservoir for the tensions system, like the 660, then you just fill the reservoir, remove the hose at the gauge and open the tailgate so the oil and air can escape from the hose.


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## Troy Farmer (Jul 31, 2011)

On my 644 I learned the hard way that before exercising the cylinder during the charging process you should disconnect the auto wrap trip mechanism. I may be slow but I almost never figured out what had happened.


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## newholland650 (Apr 20, 2015)

Thank you for all the advice. I'll see if I can borrow a hose and get it done. It is the single density system so I will have to use the hose. Thanks again


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