Cold weather problems NH TC-29

[stowepotato]

I've operated in the winter for years and usually it just takes a while to get everything warmed up.
This time, in sub-zero temperature, I let the engine run for over an hour while still in the barn to get thoroughly warm. But the loader and 3PH really groaned and complained. Not only that but they moved much slower than usual. Even after gently working with the hydraulics (which usually gets better with time) the loader functions slowed down even more to the point that I gave up. I was afraid I wouldn't make it back home if I couldn't raise the bucket or back blade and was concerned about damage to the pump, etc.
The hydraulic fluid and filter were all changed on schedule and had about 100 hours since the last change. Could it be ice in the system? But what would account for it slowing down with use? Could it be wax forming in the lines as can happen with diesel fuel?
Thoughts on best way to deal with the situation? Unfortunately, I don't have a heated place to put it and it looks like a long time before things thaw out here in northern Vermont.

 

[J_J]

Do a crackle test and see if there is any water in the hyd fluid. If so, change out the fluid for your climate.

If you want to heat up the fluid, hold the lever in relief, and the fluid will heat up faster.

 

[stowepotato]

Do a crackle test and see if there is any water in the hyd fluid. If so, change out the fluid for your climate.

If you want to heat up the fluid, hold the lever in relief, and the fluid will heat up faster.

Is holding the lever in relief the same as the float position?

 

[J_J]

NO, The relief goes off when a cyl is at the end of the stroke.

You are forcing the pump fluid past a small orifice, and therefore it heats up.

You will probably hear the squealing sound.

 

[stowepotato]

Thanks for the response. I went for 5 years on the last hydraulic oil change with no problems. This is only the second winter on the current fill. Have used NH oil every time.
Oil level is correct. This morning I drained a sample from a low point and it definitely looks cloudy, so I conclude that somehow there is water in the system. More I think about it, if there was enough water/ice in the filter that would starve the pump and account for both noise and slow acting cylinders.
Next step is to change the oil and filter. That's a hefty expense for a machine that only gets 50 hours a year usage, but seemingly no alternative.
Any ideas about how to really purge all the contaminated fluid out of the system? Can it be done before the temperature gets warm enough to melt the ice?
NH TC29 w/loader.

 

[stowepotato]

I'll try to do a crackle test, but I think I know how that's going to come out.

 

[J_J]

There might be a solution to the cloudy fluid, which is caused by the hyd fluid blended with water.

As you know, water is heavier than hyd fluid, so any water that gets in the hyd tank will go to the bottom.

So if your drain plug is at the lowest position of the reservoir, then drain about a pint in a clear jar and let it set. That will tell you if water is getting in/condensing in the tank. If it has, say about 1/4 or 1/2 in of water, just pour the good fluid back into the reservoir.

It you don't catch it, the pump will sucks it up and gets emulsified/blends the mix it into a grayish/cloudy color. After that, other compounds start to form.

If you have the assets, there are commercial units that will get rid of the water and clean up the fluid.

If the tractor is outside, keep it covered.

 

[stowepotato]

Talked with techs from two different NH dealers and both thought the filter could be clogged/frozen. Neither thought the oil looked very bad. suggestion when changing oil was to go with Hy-Trans instead of NH 134 based on the opinion that it's more tolerant of water.
BUT new development!!! Went out to change the filter today. Ran the engine for a while to help heat things a little. Tried to raise the bucket and absolutely no response to either the loader or 3PH. No noise, no resistance, no movement. The spool valve moves properly as does the 3PH lever.
Any ideas?

 

[J_J]

I would suggest that either the pump is not sucking fluid or the pump shaft is sheared.

If it has a sump screen, didyou remove it and clean?

 

[vtsnowedin]

About why it is bothering now but not before. I once had an old David Brown that had similar problems. The problem was when left outside the boots on the shift levers had cracks in them and rainwater would run down the shift levers ,past the boots and into the transmission. You needed to keep an old sap bucket handy to put over the shift levers when you parked it or the next time it was below freezing you were in a NOGO situation until you removed the water from the hydro. oil I have removed the sump p!$$ pot from the bottom and found it solid full of oily ice. You might have to build a garage for the best tool you have ever had.

 

[stowepotato]

I think it's all resolved now. The temperature finally got above 32 for the last couple of days; that helped.
For the problem of the dead hydraulics: I had tried to heat the oil by forcing it through the relief valve. Only did it for a few moments because of the extreme noise it produced. The next time I started it is when I noticed the unresponsive hydraulics. I took the relief valve out to see if it was stuck open. It didn't appear to be stuck and was clean, but when I reinstalled it I got the functions back. With the weather a bit warmer, I was able to get smooth operation as the oil warmed up.
Next step was to change the filter. Since I already bought new oil (Case Hy-Tran), I also changed that too. I haven't found a way to do a crackle test on the oil yet but will save a sample to try later. The not-so-old oil didn't really look milky but definitely dark/cloudy. I used to have a Ford NAA and indeed water would get down around the shift boot so I know what frozen solid and milky oil is. I could let it settle to see if it clears but instead will donate it my diesel mechanic for his shop heater in return for his advice.

 

[V1Rotate]

I put some cardboard in front of the oil cooler in cold weather so that the hyd fluid will warm up. Work great, and I think that helps get rid of moisture.

 

[stowepotato]

I'm not aware that I have an oil cooler. Is that only on the hydrostatic drive models?
I do have a block heater which makes a huge difference for the engine starting in cold weather.
Unfortunately, my TC-29 (gear model) sits outside most of the year and only finds room in the barn during the winter. I think it's time to build a shelter for the rest of the year. In my opinion, it's the temperature swings which contribute to condensation more that getting rained on. Either way, a shelter should help.

 

[V1Rotate]

Mine is a hydrostatic and it has an oil cooler in front of the radiator. I also put a piece of cardboard that partially blocks the radiator. Never had a problem with overheating, I can plow snow for hours using the FEL and the hydraulic hoses feel warm to the touch but by no means are they overly hot.