NH Round Baler Density problem

   / NH Round Baler Density problem #1  

RancherGuy

Gold Member
Joined
Feb 2, 2010
Messages
301
Location
Rosenberg, TX
Tractor
Kubota L3710; JD 5425, 6105R, 7130-P; IH 1086
I have a New Holland BR750 round baler. Bale density has never been adjusted for 13 years that I have had it, and density seemed good last year. This year, not so good. Bales are soft.

Looking at the operators manual and checking the baler, there is what looks like a density hydraulic cylinder and an adjustment knob. Manual says when tailgate is up the gauge should show pressure. Currently the pressure gauge for it reads zero whether the tailgate is up or down. Thus I believe the baler is running the lowest possible density when it operates = failure.

I am a bit perplexed as to how this system actually works.
(1) Looks like the cylinder is connected to a belt tensioning arm. Yes? When it works, does it pull or push the arm? Is it supposed to change length as the bale diameter grows or stay fixed length?
(2) The in & out port on the cylinder are connected together with a block for the adjustment knob and the gauge measures it's hydraulic pressure. What does the knob do?
(3) The unit seems to be self-contained. That is, it seems to be a stand-alone hydraulic cylinder, with no reservoir and no connection to any hydraulics from the tractor. How is this system to be maintained for operational health?
(4) Oil wetness exists on the cylinder's hydraulic lines. I assume it to be from itself, as opposed to leakage from the nearby tailgate cylinder. Might this mean it is leaking and has lost its oil?

In other news, the two tailgate cylinders had to have their seals replaced this year because both blew out their seals. Could it be this density cylinder is at an age where it's seals need replacement? If so, once replaced what do I do regarding hydraulic oil for it?

Thanks for any insight you may be able to provide.
 
   / NH Round Baler Density problem #2  
My guess is tension cylinder piston seal or control valve has failed. I think all one needs to is remove cyl hose from butt end of cylinder then move hyd control to tighten belts to determine if oil is bypassing piston seal & then comes out open cylinder orifice.
 
   / NH Round Baler Density problem
  • Thread Starter
#3  
I may remove the whole cylinder today and collect the seals. I am certain that after 15+ years they are not in prime condition. Then go to dealer to get new seals. That's the plan, but after that I am not sure what to do. That should address your test for the piston seal.

BTW, on the tailgate cylinders the piston seals were not the problem, the cap-to-rod seals were shot. That is, they had a bad case of deterioration, allowing oil to escape. I'm suspecting a similar possibility here but the piston seals will also be replaced in the same repair.

If it gets all new seals, what do I do next to test?
 
   / NH Round Baler Density problem #4  
I will guess next thing to check after tension cylinders would be baler hyd tension control valve.
 
   / NH Round Baler Density problem
  • Thread Starter
#5  
OK, got the cylinder seals replaced. The one between rod and cylinder cap was trash. Everything is back together and mounted on the baler. Don't know what to do next - there is no hydraulic fluid and because this is "isolated", there is no source. It doesn't even look like there is a reservoir, unless the metal box on the cylinder should be a low volume reservoir.

Who knows how the procedure to fill/purge?
 
   / NH Round Baler Density problem #7  
Go to the discussion forum Hay Talk & read Mike10 postings concerning NH equipment repairs. Mike10 is ""THE MAN"" when it comes to repairing NH hay equipment!!!!
My NH Repair Procedures, Tips and Tricks - Machinery - HayTalk - Hay & Forage Community

Don't see anything there about density or adjusting it or the cylinder(s) at all.

On my NH BR series, there is a flat faced coupler at the top of the density cylinders. That is where you fill them and or flush and refill them using your tractor hydraulics and an adapter. I got my adapter from the local Parker Hannifin distributor but I would imagine a NH dealer will have it too. You need a flat face to Pioneer adapter. Also where you check the PSI when the back door is completely open, that is when the PSI registered is the highest. I have a 4000 psi gauge that fits the coupler that I can put on to check the cylinder pressures.

Tomorrow,. when I go it to to the shop, I can grab the coupler and give you the part number and go to the NH shop manual and give you the directions for purging and refilling the cylinders.

It's not complex to do.
 
   / NH Round Baler Density problem #8  
OK, got the cylinder seals replaced. The one between rod and cylinder cap was trash. Everything is back together and mounted on the baler. Don't know what to do next - there is no hydraulic fluid and because this is "isolated", there is no source. It doesn't even look like there is a reservoir, unless the metal box on the cylinder should be a low volume reservoir.

Who knows how the procedure to fill/purge?

See my post Number 7. I can PM you the procedure if you prefer that but you will need the adapter to fill them.
 
   / NH Round Baler Density problem
  • Thread Starter
#9  
See my post Number 7. I can PM you the procedure if you prefer that but you will need the adapter to fill them.

Thanks. I did more online research and found instructions. Basically it says to connect a hyd hose to that flat-faced next to the PSI gauge and cycle the cylinder multiple times with the relief value set very low. Based on cylinder orientation the air should be purged. That seems simple enough.

Upon checking things out, I considered the 12 foot 1/4" hyd hose between cylinder and gauge to be only fair condition, so I am going to make up a new one before proceeding.
 
   / NH Round Baler Density problem #10  
Thanks. I did more online research and found instructions. Basically it says to connect a hyd hose to that flat-faced next to the PSI gauge and cycle the cylinder multiple times with the relief value set very low. Based on cylinder orientation the air should be purged. That seems simple enough.

Upon checking things out, I considered the 12 foot 1/4" hyd hose between cylinder and gauge to be only fair condition, so I am going to make up a new one before proceeding.

Glad you found it, saves me a trip to the tomorrow morning for the shop manual. If you need the catalog number off the interface coupler I can get that for you in the morning. Basically, that flat face is a bobcat style flat coupler. You install the Parker adapter on the flat face coupler with a Pioneer (or whatever your tractor uses (mine use Pioneer) on a length of hydraulic hose and run that hose to one of your remotes and pump in your hydraulic fluid. When mine starts loosing density on my BR, it's purge time.

Screw the density control knob all the way out before you purge. I like having a liquid filled 4K gauge attached to the Parker fitting all the time, that way I can check the PSI in the density cylinders and you can benchmark the maximum setting which, I think without looking is 2500 psi.

Good balers. The density control is a little strange but it does work. The tension springs are set for the lightest bale density and the cylinders really do the packing. I'll look in the morning and get you the catalog number if you need it.
 
 
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