New Holland TC35D Hydraulics won't work

[CoveyBruce]

Hi All,
I have a New Holland TC35D tractor with a 16LA front loader that the hydraulics will not work on. It has over 2000 hours on it. I was doing some clearing with it and by the end of the day the hydraulics started to get a little bumpy and the next morning they didn't work at all. So I took the pump apart didn't see anything unusual put it back together, but when I started it up it and had it on full throttle the hydraulics started to barely work like every 20 seconds or so it would move some. So I let it sit another night and the next morning it wouldn't move again, took apart the pump and it did the some thing. (The 3-point is also doing it) The HST is working.
Any help would be greatly appreciated!

Bruce

 

[jinman]

In the other forum where Bruce first posted, I told him about the location of the rubber "T", the relief valve, and the power beyond plug in his joystick valve. He's going to check all of those things. If there is something I've overlooked or some other ideas, please post them. I'm just updating everyone on what he has already had suggested.

 

[TO_Bud]

I'll throw out some thoughts that may or may not hold water because I'm not real versed in the hydraulics plumbing. Bruce said he was doing some clearing, could one of his QDs be bumped off? How about the diverter block, is the valve in the proper setting for the joystick operation? How about his 3 pt lift lever is it maxed out on lift possibly putting the system in constant relief. Don't know if any of these are valid, like I said, just trying to get the better informed members thinking. Short of these I would follow all the hydraulic lines around the tractor to see if anything is amiss as it was operating correctly for awhile during his clearing operation.

 

[jinman]

Yep, one other thing. If you remove that relief valve, set a bucket under the opening and then start the tractor for a few seconds. If fluid spews out, you'll know your pump is working and something somewhere is routing the fluid back to the reservoir without being under high pressure or that there is a blocked passage and all fluid is bypassing through the relief. Normally, if your hearing is good, you can hear fluid going through the relief valve, but if Bruce is like me, he can't hear that because of hearing loss.

Edit: Here is the order/priority of hydraulic flow:

1. PTO Diverter (diverts fluid to the PTO clutch) valve attached to the system diverter valve body, only .8 gpm of 9.8 total
2. FEL - operating the FEL will stop or reduce flow to the remotes and 3PH
3. Remote hydraulic valves - any remote operated will stop flow to the 3PH
4. The 3PH is the last in line. If it is bound up and causing the relief valve to open, the FEL and hydraulic remotes will still work because they are before the 3PH.

 

[Hooked_on_HP]

My first thought is did he snag a line and lose all the hyd fluid. When were the filters changed last.
Bill

 

[CoveyBruce]

Ok, I checked the rubber T and tightened the clamps, but it didn't seem like it was loose.

The relief valve was clean wasn't gummed up or anything. But when I started it up after the plug was out no fluid came out just a little trickle. What does this mean?

And the power beyond plug was tight.

 

[CoveyBruce]

I checked all of the lines and there doesn't seem to be any leaks.

I have no idea when the filter was changed last. I bought the tractor used, but we probably put a good 500 - 600 hours on it and we have not changed it before. So it is over due. I have one ordered it will be here in a couple of days.

 

[jinman]

Link to other thread in Hydraulics.