NH Round Baler Density problem

[RancherGuy]

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.

 

[Tx Jim]

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.

 

[RancherGuy]

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?

 

[Tx Jim]

I will guess next thing to check after tension cylinders would be baler hyd tension control valve.

 

[RancherGuy]

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?

 

[Tx Jim]

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

 

[5030]

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.

 

[5030]

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.

 

[RancherGuy]

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.

 

[5030]

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.

 

[Tx Jim]

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

Due to the fact I don't own or repair NH hay equipment therefore I haven't read Mike10's numerous NH repair procedures but I'll venture to guess if RancherGuy asks his question on Hay Talk he'll get an answer to his baler problem!

 

[Rustyiron]

The round bailers that I've been around use what's called an "accumulator" in the hyd. system. It's a small "tank" looking thing usually with a pressure gage hooked to it. It acts like a shock absorber in the particular hyd. Circuit its plumbed into. It maintains a consistent pressure to the belts as the bale grows for the same bale density from the middle to the outside, or is supposed to.
I would look into charging it or some other problem, not the cylinder seals that were mentioned, esp if you do not see signs of leaked hyd. oil.

 

[5030]

Due to the fact I don't own or repair NH hay equipment therefore I haven't read Mike10's numerous NH repair procedures but I'll venture to guess if RancherGuy asks his question on Hay Talk he'll get an answer to his baler problem!

he found the answer and I also gave it to him in as much as I run NH round balers.

 

[5030]

Went out to the tractor shop and pulled the fitting and gauge. The flat faced fitting is a Parker Number PD242 and a WIKA filled gauge 0-3000 PSI. The threaded end of the Parker flat face fitting will accept a male hydraulic hose fitting.

Far as the previous post about an 'accumulator'. There is none other than the hydraulic fluid in the density cylinders.

Adding / changing fluid in part:

Connect a tractor hydraulic system with compatible oil to the QD fitting (see above).
Turn the relief valve counterclockwise to it's lowest setting.
Use the tractor hydraulic system to extend and retrace the cylinder(s) several times to purge air from the system.
Place the tractor hydraulic system in FLOAT position to remove pressure from the system.
Remove the hydraulic hose and adjust the relief valve (black knob at the bottom of the cylinder(s) to set required pressure (sing a gauge on the fitting and reading the pressure or by checking a bale.
Cycle the tailgate several times. If there is pressure in the system WITH THE TAILGATE CLOSED bleed thr system via the fitting at the top (flat faced coupler). I crack the hex fitting below the elbow to let any air out. recommend fluids aren't what I run. I run Chevron AW THC Synthetic. Don't seem to matter other than not using any cheap 333 fluid because it won't prolong seal life, it's obsolete.

Hope that helps

 

[RancherGuy]

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

Thanks for your input on this and your following comments and notes.

Adjusting is not a problem. The operator's manual explains: with gate closed, set relief value. Lift the gate - the pressure gauge should indicate pressure. Opening the gate extends (pulls) the hydraulic cylinder just like a growing bale does. Closing gate should be zero pressure. Repeat as required.

 

[5030]

Thanks for your input on this and your following comments and notes.

Adjusting is not a problem. The operator's manual explains: with gate closed, set relief value. Lift the gate - the pressure gauge should indicate pressure. Opening the gate extends (pulls) the hydraulic cylinder just like a growing bale does. Closing gate should be zero pressure. Repeat as required.

Also, keep in mind that the coil springs apply pressure as well and are adjustable. NH says as the belts wear in, you can adjust the tension to eliminate belt slippage during initial bale formation, I've never adjusted mine but what I did do was install a set of infeed discs. They allow the baler to run a bit easier but they do scuff the outside of the bales a bit. I'm not into bale astehtics so I don't care and I don't believe the steers do either.

Goof luck, you have the information you need now, glad to help.

 

[RancherGuy]

... flat faced fitting is a Parker Number PD242 ...

Thanks for that detail! Looks like it is described as a "test/diagnostic" fitting. It is not a standard 1/4 flatface fitting. The 1/4 fitting uses a 16mm male, while this is a 12mm male. The $40 PD242 coupling I ordered is labeled as "1/8" Body Size, 1/4"-18 NPTF Thread Size". Interesting.

 

[RancherGuy]

To provide closure on my end - I now have properly operating density. Here is a summary of what I did:
1. Replaced 1/4 hydraulic line between front gauge and cylinder. It is 15 yrs old and I didn't want to mess with a failure in the field.
2. Replaced all seals inside the single hydraulic cylinder using a complete kit from the dealer.
3. Connected tractor's hydraulic to the special flatface fitting at the pressure gauge.
4. Cycled the baler several times between full pressure & release.
5. Assuming I had most or all air out of the density system, I disconnected from the tractor.
6. Screwed in the adjustment knob at the base of the density cylinder.
7. Opened the tailgate and noted the gauge pressure. It was a bit higher than I wanted, so I backed off the adjustment knob until it was where I wanted.

I have made over 100 bales and they again look great!