JD 2555 losing hydraulic pressure

Needs some advise what might be happening. Was plowing the drive today and lost power and hydraulic operation while moving down the driveway. Steering pressure, loader and 3 pt was also out. Let it sit and run while I checked things over and had power again when I got back on. Took about 3 minutes. Tried to finish the drive and it happened several more times by the point when I got it back in the barn. Oil Levels looked good, no leaks or heat found. Oils looks clean and did not have a bad odor. I had full power and all hydraulic operation when it came back up and ran. Any thoughts? I’m thinking I may have a blocked filter.

(quoted from post at 11:34:55 12/16/17) Needs some advise what might be happening. Was plowing the drive today and lost power and hydraulic operation while moving down the driveway. Steering pressure, loader and 3 pt was also out. Let it sit and run while I checked things over and had power again when I got back on. Took about 3 minutes. Tried to finish the drive and it happened several more times by the point when I got it back in the barn. Oil Levels looked good, no leaks or heat found. Oils looks clean and did not have a bad odor. I had full power and all hydraulic operation when it came back up and ran. Any thoughts? I’m thinking I may have a blocked filter.

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If you can not remember the last time the transmission filter was changed and the screen checked . Both are sadly over due .
How are the loader hydraulics plumbed into the tractor ?

If I remember correctly they run to the bottom of the trans case near the internal filter housing

1st thing you need to do is change hyd filer & check/clean hyd sump screen.

Depending on type of loader valve if it's the convertible type from open center to closed center it could have blown an internal seal letting valve revert to open-center. Simple test is remove loader valve return hose from tractor then aim open hose into a bucket then start engine,with FEL control valve in neutral no oil should exit hose. Do hyd's act the same with hyd pto in both on/off positions? Does tractor have option of hyd hi-lo? If so do hyd's act the same in both speeds? With 3 pt raised,engine running look in hyd filler hole behind seat for spraying oil.

You are about to open "Pandora's Box"..check the sump screen and filter,, but you most likely have a transmission pump leak inside,,could be a cracked line or a worn seal ring/housing,,the way this system works the oil is drawn through the sump screen then through the transmission pump, then through the oil filter, then some is directed to shaft lube,,then a 5/8" steel line takes what is not used up to the shift cover to satisfy a pressure regulating valve then to the Hi/Low shift valve and the Independent PTO valve..and Then what ever is left over goes back down out of the shift cover via another 5/8" line and on to feed the main front pump..when things start going the way your's is...there is not enough left over to feed the front pump,,you leave it set a bit..the oil cools down a bit... and trying it again it will work for a bit,,then the oil warms up and the flow slows enough to not let the regulating valve open..then no oil gets to the front pump...there are several place and ways this charge oil gets miss directed,,and it can drive you crazy finding the problem spot,,with luck you have a cracked pipe,,and when you look at these pipes look very close,, I have seen cracks so fine that you can hardly see them, but when they open up from pressure and hot oil they leak like the working end of a Fire hose..we talked about why 2950/55's are getting cheap in the equipment sale books...this is the Primary reason.. as I have said before when this model style tractor is good they are very good,,when they go bad they are very bad. So start with the basic checks and tell us what you find and if you don't see what is happening we can walk you through the steps and hopefully speed up your diagnoses time..

My money is on what Tx Jim is saying. Have fixed dozens with this issue,on 20 through 55 series. Deere almost conceeds
to to issue by offering a "Rockshaft Overhaul Kit" AL 57954. If it is open station and in my shop its it at 1:00 out by
5:00

Are you sure its not freezing up? I have seen enough moisture in hydraulic/transmission oil that it had ice crystals in it plugging filters and screens.

(quoted from post at 12:29:53 12/16/17)
1st thing you need to do is change hyd filer & check/clean hyd sump screen.

Depending on type of loader valve if it's the convertible type from open center to closed center it could have blown an internal seal letting valve revert to open-center. Simple test is remove loader valve return hose from tractor then aim open hose into a bucket then start engine,with FEL control valve in neutral no oil should exit hose. Do hyd's act the same with hyd pto in both on/off positions? Does tractor have option of hyd hi-lo? If so do hyd's act the same in both speeds? With 3 pt raised,engine running look in hyd filler hole behind seat for spraying oil.

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This tractor has a 146 loader attached, I will start with your list of items to investigate this week. Will need some new filters to start with. It does have two ranges in the trans, I didn’t try the pto when it acted up. I did loose the 3 point when the trans would not move the tractor.

(quoted from post at 12:29:53 12/16/17)
1st thing you need to do is change hyd filer & check/clean hyd sump screen.

Depending on type of loader valve if it's the convertible type from open center to closed center it could have blown an internal seal letting valve revert to open-center. Simple test is remove loader valve return hose from tractor then aim open hose into a bucket then start engine,with FEL control valve in neutral no oil should exit hose. Do hyd's act the same with hyd pto in both on/off positions? Does tractor have option of hyd hi-lo? If so do hyd's act the same in both speeds? With 3 pt raised,engine running look in hyd filler hole behind seat for spraying oil.

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Update, just completed a filter and fluid change. Filters looked pretty good but did hind chunks of materials and thick black paste in the screen filter. The chunks look like friction material, i haven’t tried a magnet on them yet. When started (problem 2, battery’s keep discharging) she fired up and ran Great. No issues with the trans, loader, 3pt, PTO, or any runability issues. Just took off like there was never a problem. I think I will take the screen and junk in it to the dealer I bought it from to have them review it. I was told there was a 2 year Warrantee on it from my purchase. Might be a good thing for them to see. I may pick up some replacement filters just in case these plug up as well.

This photo is the material I flushed out of the screen opening in the side of the trans housing. The filter was a bit difficult to remove so I figured there was more in there that needed to come out.

(quoted from post at 12:29:53 12/16/17)
1st thing you need to do is change hyd filer & check/clean hyd sump screen.

Depending on type of loader valve if it's the convertible type from open center to closed center it could have blown an internal seal letting valve revert to open-center. Simple test is remove loader valve return hose from tractor then aim open hose into a bucket then start engine,with FEL control valve in neutral no oil should exit hose. Do hyd's act the same with hyd pto in both on/off positions? Does tractor have option of hyd hi-lo? If so do hyd's act the same in both speeds? With 3 pt raised,engine running look in hyd filler hole behind seat for spraying oil.

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Tx Jim,

Any additional thought about this condition!

Thank you, Greg

If tractor hyd's are operating correctly then I think you'll be fine for a good while.

(quoted from post at 07:56:33 12/27/17)
If tractor hyd's are operating correctly then I think you'll be fine for a good while.

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Thank you,

Greg

Water in the oil can plug the filter with ice crystals

(quoted from post at 13:07:59 12/27/17)
Water in the oil can plug the filter with ice crystals

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Thankfully I did not fine any evidence of water in any of the oil. I let the buckets sit overnight to settle hoping to make a good evaluation of any contamination

Wildride47
To check for presence of water in oil one can put a small amount of oil in a pan & carefully heat oil. If crackling sound is heard while oil is heating then water is present.