Hydraulics SLOOOWWWW

Spicer · Dec 17, 2014

As soon as you showed us a picture of the oil, that’s when it got complicated.

I would not take my diagnosis as a given. I would first open the filter and let it stand for a day and post a picture for any of us to identify any problems.

Another possibility that is beginning to make more sense is that the transmission was never completely drained and the remaining water has been circulating through the bottom of system for the last 20 or 30 years. The only clue was you had mentioned “drained the case (properly)”. If this is the case then the filter would be completely covered with rust. We really need to see what’s in the filter.

Suggested Procedures:
1. Clean the crud out of the sump.
2. Flush the system by circulate diesel fuel through the transmission.
3. Fill the case with diesel w/biocide if needed and add a new filter.
4. Start the tractor and activate all of the hydraulic and let it stand for 2 days. Do not add any load to the hydraulic system or run for more than 5 minutes.
5. Drain cylinders and transmission.
6. Add NH 134D oil. (The oil that you posted met these requirements)

I have a few corrections on this thread.
1. The most common biological contaminations are bacteria and fungus, but algae’s also grows in hydraulic systems.
2. If the priority valve bias spring broke you would lose your power steering. (Unrelated to the task at hand)

Mike

sruman · Dec 22, 2014

Ok. I've got things started. Drained all the fluid, scrapped as much of the sludge out of the bottom of the trans case as possible. Filled case with diesel and let it stand for a few days now.
Looking at the oil, I think its just filthy (maybe some water mixed). I think back and i only changed the oil once when it was bought, so who know how long it sat. Maybe this change was needed to serve as a good "flush". I have gone through 3 filters since buying it. Either way, it's full of diesel now.

Another question. I have the hydraulic piston pulled from under the seat, and I'm replaceing the seals. the piston seal (white plastica) has a lip on in. Should the lip of the seal be towards the top or bottom of the piston?

Also, it there a trick to getting this on the piston? Going to be tighter than....well....you know.

Spicer · Dec 22, 2014

The lip of the seal is on the pressure side of the piston. You will have to heat the seal in boiling water.

Pclausen had an excellent post.
Piston & Lip Seal

Pushing the piston and seal into the cylinder is also difficult. I would use a large arbor press paying close attention to the seals insertion. Try not to damage the lip itself.

Don't allow the pump to Cavitate. This creates surface pressures higher than the pump gears can withstand and will eventually eroded these gears.

At lower RPM's cavitation sounds like buzzing and at higher RPM's it sounds like squealing.

Mike

sruman · Dec 26, 2014

ok, quick update. I have the bio-cide in with the diesel, in the case soaking. I've had a bunch of sludge in the bottom of the case, that I scooped out with the mrs. gravy ladle (yeah, she's not happy). I hooked up all the pipes, put on a new filter. finished the TPH piston seal, and re-assembled.

Now, just a few other basic questions:
* Do I start the tractor and circulate the diesel throughout the entire system? (expand all hydraulic cylinders on FEL and TPH).
* Are there torque requirements on the bolts that I've used (pipes, TPH cylinder bolts, drain plugs, etc).
* how long should I soak in the diesel?

Spicer · Dec 27, 2014

Good job, you're almost there.

Important:
Your hydraulic pump will most likely lose it prime and will not pump fluid. The reason is that unlike conventional hydraulic systems yours uses a priority valve. This valve keeps 500psi or so of back pressure on the steering valve and will restrict or cut off the flow to your system. You will have to fill your hydraulic filter with fresh hydraulic fluid and loosen the pumps pressure side banjo bolt(attached to tube #3) until the system is primed.

View attachment POWER STEERING TUBES%2C 1910.pdf

You should start the tractor and extend and retract all of the cylinders a couple of times. You should not allow them to extend to their limits. We do not want the hydraulic system to operate at it's maximum pressure nor do we want the system to operate for more than 5 minutes.

You should drain the system immediately after you shut the tractor down while the sediments are still in suspension in the diesel fluid.

When you drain the system you will have to determine if you removed the majority of the rust sediment by opening the mounting plate for the banjo fitting. If you find that there is still a considerable amount of sediment you will have to continue flushing diesel through as described previously.

I do not have the torque values for your 1910.
IT manuals are written in a minimum information fashion, but they will most likely have torque tables.

IT 1910 Manual

Mike

Spicer · Dec 27, 2014

In a previous post I mentioned that you should allow the biocide to remain throughout the system for two days, this is a good idea. On that second day I would repeat the extend and retract procedure then drain immediately.

Mike

sruman · Jan 3, 2015

Ok. Finished up this weekend, and everything appears to be in working order. I can say, that from the sludge removal, I think that was a culprit in the clogging of the filter. I also think that from the amount in the case, that even with new fluid, it was being ruined by the sludge slowly working through the system. As a recap, I've fixed the piston and ring for the TPH, and it is working perfectly. I've soaked the hydraulic system with diesel and biocide, circulated a few times over the course of 2-3 days. Drained, cleaned out remaining sludge after soak (although not much could be found at all), new filter, refilled with new fluid, and everything seems to be in good working order.

Thanks for you help. This thread should be placed in a top 10 list for hydraulic system re-conditioning.

Spicer · Jan 4, 2015

I'm glad it worked out.

I will add that in later models like the XX20 there is a suction screen in the sump that could clog over time.

Paying close attention to the sound of the hydraulic system is important. A hydraulic system makes a certain amount of noise, but if you hear a buzzing or squealing over the engine noise then there is most likely a problem.

I was able to find a video on cavitation but unfortunately the video was not synced to the audio and air was entering the system through the seal on the hand valve.

If you listen to the video carefully you will hear portions where the pump and the motor can be heard. While it’s cavitating you can only hear the pump buzzing with out any motor noise. Keep in mind that the video’s audio gain adjusts on its own, Cavitation is quite loud.

Mike

sruman · Jan 18, 2015

Just wanted to follow up. It's been a month or so, and I haven't had any issues with the system. All is well. I never heard of algae contamination before. This was a great project, and anyone who has issues, please follow the bouncing ball, and this should diagnose most issues.
Thanks to all involved.