New Holland TC35D Hydraulics won't work

[J_J]

I believe I wold take it into a hyd shop and have them test the pump. Then get an estimate if it needs repair.

Maybe they can fix it there or order a re-manufactured pump.

 

[JerryG]

The thing that causes hydraulic problems the most on compact tractors is when you have a quick disconnect that isn't seated right. Check all of them. Some will look connected good and won't be.

 

[jinman]

I believe I wold take it into a hyd shop and have them test the pump. Then get an estimate if it needs repair.

Maybe they can fix it there or order a re-manufactured pump.

I agree. It's time to seek professional help. You can get a seal kit for that pump and have the shop install it and check the pump. Frankly, they can look at the pump's parts and tell you if it is too worn to repair. I'd have them inspect it before buying the parts. You can do a Yellow Pages search or even a computer search for shops in your area. You might also go into a NAPA autoparts shop and ask them if they know a hydraulics shop to recommend. In the end, I think you need trained eyes looking at your pump or just go ahead and buy a new one. I have great confidence in my New Holland dealer's shop and got them to look at my pump and install seals. It cost me less than the price of a seal kit to have them do it because I took them the pump and picked it up. They only replaced the seals I needed. Unless you are completely at odds with your nearest large New Holland dealer, I have to believe that would be your best bet.

 

[CoveyBruce]

Yes, I agree.

Just out of curiosity, what could have caused this problem? or is it just out of wear?

 

[J_J]

If you have had the tractor since 2001, about how many filters and fluid changes have you done?

A 10 micron filter will filter out those particles over 10 microns, but those particles less than 10 microns is what helps grind away at internal parts.

There are devices out there that will help you clean the fluid.

On one of my Kohler engines, I have a regular filter, and a 1 micron bypass filter, and it is not cheap.

What it does is, if the engine is running, fluid is filtered by the regular filter, and a small amount of fluid is sent through the 1 micron filter, and over time, you will have a super clean fluid.

 

[CoveyBruce]

We bought it used about 5 years ago. We have not replaced the filters since then. And I have no idea how many times they replaced them before that.

 

[jinman]

Yes, I agree.

Just out of curiosity, what could have caused this problem? or is it just out of wear?

Bruce, on a tractor that you did not own new, you just never know how it has been operated. The problem could have started before you got the tractor. There has been at least one other person in the NH forum here that had a worn out pump. Certainly, fluid and filter changes are important, but I've let my fluid go out past 500 hours because it looked almost perfectly fresh. I think the 300 hour change cycle can be extended, but only if the fluid looks pristine as mine did. Mine was so clean I could hardly see it on the dipstick. You described your original failure as happening pretty rapidly and I don't see that as a failure from wear. That kind of failure seems to indicate something inside the pump failing.

You said you took the pump completely apart and put it back together. Did you replace any of the internal seals when you did that (items 10, 11, 12, 13)? The diagram below shows internal seals that are renewable. All the numbered components with a black dot beside the number are part of the $189 seal kit. Damage to one of those seals might not be seen by the unexperienced eye. I suspect it does not take much to cause enough vacuum loss to disable the pump, especially when the HST charge pump is competing for fluid from the same filter and piping. Having someone who has experience look at the seal conditions and bushings for wear could make this a whole lot easier on you.

When I got my pump seal kit installed, I just poured a a couple of tablespoonfuls of hydraulic fluid into the pump so I knew it was lubricated. I installed it back on the tractor and hooked up the piping. All this piping had loads of air in it and I didn't bleed it whatsoever. I started the tractor and let it idle for a few seconds and checked that the 3PH would raise. It worked perfectly. The system primed itself and the air slugs in the piping returned to and escaped from the reservoir. I didn't have to do any kind of fluid priming. I'm saying all of this to state that the system works fine when the pumps are in good shape. They will self-prime and clear the piping of air. The fact that your pump won't self-prime means that small amount of vacuum at the inlet is just not normal nor sufficient to get the system pumping. I think all your problems are going to be found inside your pump. It seems you've proven that over and over. I don't know what else to tell you.

 

[CoveyBruce]

Sorry for the delayed reply, internet wasn't working.

I didn't take the pump completely apart just the inlet and outlet pipes and the "panel" on the back of it.
And, no I did not replace anything.

 

[CoveyBruce]

Just a quick update.
I did get the tractor working. It was the hydraulic pump after all. We found out when we took off one of the outlet lines on the pump. It had a small screen in it and it was full of metal shavings. But we were about ready to put the new pump on when we discovered a leak in the suction line. There is 90˚ angle right above the pump, that is welded together and it had a crack in it. So we had that welded and now we are back up and running.
Thanks to all,

Bruce

 

[jinman]

Glad to hear of your success, Bruce. I know it also must have been pretty expensive. I never thought about that 90 degree pipe weld being a problem, but if the big tube ever got a serious blow from something the tractor ran over, it would really stress that 'weakest link' at the 90 degree point. That little screen at the inlet to your diverter valve sure told a story with those metal particles. When I had mine off, it looked like a little organic goop around the edges, but the screen was very clean. It's amazing what you can learn from a little thimble sized screen.