M5400 blowing front shaft seal on hydraulic pump

[lilolpace]

I recently bought a m5400 4x4 w/FEL. The unit only has 1300 hours on it. Seems to run strong with no issues there, however, not long after I got it home I hooked up my bush hog. When I did this I was only able to successfully run the machine approx 30 minutes before I lost steering and it pumped my crankcase full of hydraulic fluid. I found the vent tube to the rear cases to be clogged. I thought this was my problem. Therefore I cleaned it out, put a new seal in my hydraulic pump, changed all my fluids and filters, got everything primed back up. Worked great for an hour and then went to @#$! again. same thing. I found some wet disc looking material in the hydraulic filters.... Looks almost like pieces of a motorcycle friction clutch disc... any ideas where that came from? Hope I didnt buy a lemon as I gave the fellow almost 15,000 for the tractor any help and advise would be greatly appreciated. I also noticed that when I lifted my bush hog all the way up that it didnt want to steer and the loader didnt want to work but if I lowered the bush hog just a hair everything went back to normal. Is there a PRV somewhere thats not too much of a booger to get at and clean out?? A way to flush the system without blowing another seal and costing me another 200.00 worth of oil etc?

 

[lilolpace]

Any ideas guys? I really need to get this fixed....

 

[olthumpa]

I had the same thing happen to me while bush hogging. Changed fluids and seal and back in business. About an hour of mowing - - whoopssss fubar #2.

Pulled the hydro pump off, took it to a hydro shop I patronize to have them check it out before spending any more $$$. The pump was junk! They had a pump in stock that would fit my tractor so out the door I go with a new pump and lighter wallet. 3+ years later the pump is working great and no more hydro in the engine oil. That's my story and I'm sticking to it.

Not saying that the pump is your problem but I would make sure that it is working properly before anything else. I would also check any hydro pressure relief valves you have in your system. Depending on your system configuration, if you have a pressure relief valves that is sticking closed it can cause you to blow out the front oil seal in the pump.

 

[North Idaho Wolfman]

I would be worried with it having "clutch" material in the filter.
It could be something in the transmission giving out.
I would get a parts manual and check for any parts that might resemble the material you found.
When you raise the 3 point to the top is it possible that you've run it low on fluid and that's the reason for the steering and FEL to go dead?

 

[lilolpace]

Thanks guys, Im fixing to drain all the oil and clean/check filters again.... Where are the pressure relief valves at.... on the blocks that are under the seat? is there more than one?

 

[lilolpace]

do I pull off both of the blocks in the pics? what is that plug? or what not in the second picture is that something I need to clean? Im fixing to wash all this down before I proceed and go from there.... are there any specialty tools needed to disassemble those blocks?

 

[lilolpace]

Ok, so in the meantime I called the local hydraulic repair shop (hydratech) to see what they would charge me to check out and test my pump. they said that they will test it but with gear driven pumps they take them apart first to make sure that they dont see any issues before they re assemble and test so that no one gets hurt when they pressure it up. Then they will give a quote to fix it or what not, but stated they cannot get parts for the kubota pump. therefore is anything is wrong with it I would just have to replace them pump rather than rebuild it. Should I let them take the pump apart etc before I proceed....? said that there is no charge to take the pump apart and check it out and give a quote to fix it...

 

[lilolpace]

is it going to make things worse to let someone dis assemble my pump?

 

[lilolpace]

Pump was trashed, over pressured and extreme heat is what they said caused the failure. I have another pump on the way. In the mean time I found two pressure relief valves under the seat. I disassembled them and cleaned them etc, however, they were not dirty at all. everything looked brand new. I drained what was left of the hydraulic fluid (it was clean as a pin). Removed the filters and they looked good as well. Blew out the lines with compressed air. Is there anything else I can or should do before installing the new pump so as to try to prevent this from happening again? I cant afford to ruin another 1500.00 pump.

 

[Apogee]

I'd be putting a pressure gauge on the unit once the new pump is installed to make sure it's operating at the correct pressure. You want to make sure the pressure relief valves have not been modified or dialed up to too high a pressure.

 

[lilolpace]

Where would I install the gauge at? Is this something I can setup and test myself? There are a lot of lines on this machine so I dont know at which point I would need the gauge installed in order to test the PRV's....