H6830 New Holland Disc Mower

aj2n · Sep 11, 2011

Hey guys, I've got a New Holland Pull-type disc mower that we bought about a year and a half ago. The mower works great but there's an issue with the hydraulics. The Cutter bar doesn't raise and lower level. The end of the cutter bar closest to the tractor drops a ton quicker than the opposite side. I was wondering if anyone had any suggestion about how I could fix this problem.

Thanks guys hope to hear back with some good feed back.

aj2n

5030 · Sep 11, 2011

I take it it's used?

Sounds like the restrictors just ahead of the cylinders are not sized properly. In the hose that feeds each cylinder, at the end, just before the cylinder itself, is a restrictor disc that restricts flow so the head lowers smoothly and don't drop like a rock. The farthest restrictor must be slightly larger (in orfice diameter) than the closer to the tractor restrictor. Sounds like they need switched. Real simple fix, about 5 minutes.

aj2n · Sep 11, 2011

Actually we bought it new from the dealer. They shipped it in and one of the mechanics in the shop assembled it. If it's what you say it sounds like a simple mistake. How hard is it to swap the two pieces out and get it to drop correctly.

Thanks
Alex

5030 · Sep 12, 2011

Stuff like that happens. My NH dealer is no exception. My new 575 had no oil in the hydraulic bale tension pump...but I checked it. No biggie.

Lower the head to the ground, Shut down the tractor, relieve the hydraulic pressure but leave the hoses attached to the couplers (the vacuum of the fluid in the closed and coupled lines will prevent much fluid from leaking out)...it's expensive...

A couple open end wrenches and break the fittings at the cylinder fittings. The restrictor discs will be in the male fitting on the cylinder itself. You might need a wire to fish it out. Compare your orfices and put the larger orfice in the outboard cylinder fitting and button the lines back up and go. Mine are little brass rings, look like washers with a small center hole......

The restrictors are in there so the head don't drop too quickly and possibly damage the cutterheads....if operated by a dummy. I took mine out because I'm the only operator but you have to watch how you lower the cutterhead....and raise it. The also restrict fluid movement as the head rides over uneven ground, like a shock absorber sort of. Mine are in a plastic bag in the tractor toolbox.

Tx Jim · Sep 12, 2011

aj2n said:
Hey guys, I've got a New Holland Pull-type disc mower that we bought about a year and a half ago. The mower works great but there's an issue with the hydraulics. The Cutter bar doesn't raise and lower level. The end of the cutter bar closest to the tractor drops a ton quicker than the opposite side. I was wondering if anyone had any suggestion about how I could fix this problem.

Thanks guys hope to hear back with some good feed back. aj2n

I'll guess that the lift cylinders are the master/slave type(similar to the Vermeer TM series disc cutters designed to keep the cutterbar level and the master is leaking internally. Incidentally the photos on NH website of the H6830 resemble a Vermeer TM series very close.

aj2n · Sep 15, 2011

Hey 5030, thanks man that's a really good description of everything i've got a pretty good idea of what I need to do. I'll give it a shot when I get home this weekend. That's a great help. I'll let you know what I find out.

Aj2n