Help! NH 3 point won't go down

tallyho8 · Aug 21, 2008

My Ford/New Holland 4610SU had been working perfectly all week and I finally got around to checking the hydraulic fluid in the rear axle. I got out my manual and removed the rear axle oil level plug and it was low so I raised the 3 point hitch per instructions and added 2 gallons of utf (it holds 12 gallons) until it reached the oil level plug. I replaced the plug and filler cap. I started my engine and lowered the 3 point then raised it and went to lower it again and it won't lower. It has my 8' flail mower attached so there is plenty of weight on the 3 point.

What happened? I checked my shop manual under troubleshooting and it lists lots of things to check if the 3 point won't go up but it has no list for if the 3 point won't go down.

Soundguy · Aug 21, 2008

My bet is there was alot of gunk in the sump, and pouring in 2g of oil stired it up, and a piece lodged int he unloading ( control ) valve.. perhaps the exhaust portion.. etc.

If this were a 4600 I'd ask if it had a remote ont he top cover or the blank 3x5 hyd plate.. if so.. you could loosen that plug onthe top blank plate and see if oil came out.. or not.. but I'm not familiar with the 4610..

is it at max lift? if not.. take it up and then see if it will drop... got an ASC valve? didya mess with it accidentally?

soundguy

bruceatlam · Aug 21, 2008

I just worked through a similar problem on my Kubota --- it may not help you at all, but it's a short thread to read through;

http://www.tractorbynet.com/forums/kubota-owning-operating/124896-b20-tph-stuck-fully-raised.html

tallyho8 · Aug 21, 2008

I don't have an ASC valve. It is at max lift. I did not mention that the first time I let the 3 point down after I added oil, it went down kind of fast so I turned the flow valve to slower and then the next time I tried to let it down it would not go down even if I moved the flow valve all the way to fast and then back and forth a few times. Could the flow valve be stuck shut?

I am afraid to try disconnecting things or loosening bolts, covers, etc because there has to be some very high pressure trapped in the system somewhere keeping my 1000 pound flail mower up in the air. If I loosen the wrong thing and release the pressure my flail mower will drop quick or some high pressure will make the loose part go boing and disappear and I don't want to get sprayed with any high pressure hydraulic oil.

bruceatlam · Aug 21, 2008

"Could the flow valve be stuck shut?"

I think that happened in my case --- don't know if you read thru the thread or not. I can't envision how it could happen, but just as soon as I started to remove the cap on the TPH cylinder(my flow valve is mounted through that cap), I think I freed something up and then when I opened the flow valve, the TPH started to lower. Go figure --- I can't. But, it works as it should now after its little "stuck" episode.

Can you get the mower off somehow?? Another tractor with a loader?? Block it up??

tallyho8 · Aug 21, 2008

I loosened a plug (31) on the accessory cover on the lift cover and let the fluid slowly flow out to allow my 3 point to go down so I could remove my flail mower. As soon as I started it afterward the 3 point went back up. I just moved the tractor down my driveway a short distance and it felt real hot by the flow control valve plate so I think the pump is building up a lot of pressure that is not being relieved some way and I better run my motor as little as possible while I diagnose my problem.

It's late now. I will try to find time to work on it a little tomorrow.

Eagleview · Aug 21, 2008

Do you have an obvious leak ? 2 gallons is a lot of oil to replenish . Are you sure it's not overfull ?

Soundguy · Aug 21, 2008

tallyho8 said:
I loosened a plug (31) on the accessory cover on the lift cover and let the fluid slowly flow out to allow my 3 point to go down so I could remove my flail mower. As soon as I started it afterward the 3 point went back up. I just moved the tractor down my driveway a short distance and it felt real hot by the flow control valve plate so I think the pump is building up a lot of pressure that is not being relieved some way and I better run my motor as little as possible while I diagnose my problem.

It's late now. I will try to find time to work on it a little tomorrow.

I think you need to check the exploded diagram on your unloading valve system and relief to study the oil flow circuit. If pressure was not being relieved.. a seal would blow.. or oring.. or shaft seal..etc..

if your 3pt control is down, and the lift goes up when you power it up.. unloading valve sounds stuck...

soundguy

tallyho8 · Aug 27, 2008

I finally got it working again today.

Thanks to everyone for giving me info on the repairs, especially, JC-jetro, who emailed me a lot of info and encouragement on trying the repairs myself.

I do not know exactly what was wrong but this is how I fixed it. I removed all the valves and plugs in my flow control plate, one at a time and let some fluid out of each one and worked the position control and flow control knobs as I was doing so. This included the flow control valve, oil cooler valve, check valve and miscellaneous plugs. I started my engine and worked the controls a few times and PRESTO it started working again. My next step is to change the hydraulic fluid (12 gallons) and filter to hopefully, prevent it from happening again.

Without the help from TBNers, my tractor would be in the shop and I would be looking at a >$1000 bill.

THANKS TO ALL!!!!!!!!!!!!!!!!!!!!!!!!

JC-jetro · Aug 27, 2008

tallyho8 said:
I finally got it working again today. Thanks to everyone for giving me info on the repairs, especially, JC-jetro, who emailed me a lot of info and encouragement on trying the repairs myself.

I do not know exactly what was wrong but this is how I fixed it. I removed all the valves and plugs in my flow control plate, one at a time and let some fluid out of each one and worked the position control and flow control knobs as I was doing so. This included the flow control valve, oil cooler valve, check valve and miscellaneous plugs. I started my engine and worked the controls a few times and PRESTO it started working again. My next step is to change the hydraulic fluid (12 gallons) and filter to hopefully, prevent it from happening again.

Without the help from TBNers, my tractor would be in the shop and I would be looking at a >$1000 bill.

THANKS TO ALL!!!!!!!!!!!!!!!!!!!!!!!!

Good job Dudley

Sweet.

Keep it up. You need Ford 134, TSC Mystick works just fine and it is not prohibitively expensive. you got to do both cleaning the inlet screen and replacing the cartridge filter.

JC

Help! NH 3 point won't go down

tallyho8

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