John Deere 8300- power shift leaks

The tube behind the hub is the transmission vent. Usually a leak there means the transmission is overfull. That can be caused by the sump screen being clogged or the incorrect transmission scavenge pump parts may be installed. Had the transmission been worked on before leak started? If you remove the drain plug from the transmission, you should get about 4 1/2 gallons of oil. If it is more, the transmission is overfilling. If not overfilled, the flywheel damper could be bad and it pulls transmission hub out of transmission too far.

Thank You! I have cheeked what did You wrote me. And what we agreed:
1. We take out drain plug in the bottom of transmission and received about 18 litres( about 4. 7 gallons) of oil.
2. We have check the damper and its ok. It doesn't pull the hub.
3. We have bought this tractor used, but after that we didn't repair scavenge pump- we have replaced only pump bearings- bought bearings in authorized John Deer Parts dealer.
4.The sump screen isn't clogged.
5. The transmission had been worked with no leaks until now.

But what we have check, I saw that in Manual repair of 8300. There's in Neutral position of leaver,and I see flow of Lube oil into this tube what for?? I have add a picture with marked canal. On the legend You can see what each colours means. I have learned that there's a lube cut-off valve. Maybe it is jammed?? We have matched the lube oil pressure and repair manuals, and it's disagree. I add second picture where we cheek it. And here is a matches, manuals- ours measurements:
1. With clutch pedal full down manuals:0,9 bar(13. 0 PSI) our mensuration 6 bar (87.024 PSI)
2. With clutch pedal full up manuals: 0,75bar (10.8 PSI) our mensuration 4,5 bar (65.268 PSI)


LEGEND to first picture :
1 - System 1 Oil
2 - Lube Oil
3 - Sump Oil
4 - Rotating Shafts and Gears

I'm not sure why the book shows lube oil to that tube. I believe it may be a mistake in the manual. Your lube oil measurement is definitely too high. I would remove and inspect the lube cut-off valve. It may be stuck. Aside from the leak you have, is the transmission working properly in all gears? What rpm and oil temperature did you test at?

:hi:
So now we have replaced out of tractor the transmission :flag_of_truce: !It was act of our desperation We checked all valves and seems to be fine!!! So we called to John Deere local dealer and they want to have it, and check themselves! The John Deere supervisor said that Power shift Transmission have to be put in special toll- in a stage, a dock station- to check it, is this true?? JD last question, What is need for ground speed pump in John Deere?? When I try to translate it in Polish it gives me a nonsense!! Write me place what is this for??

Thanx for all
Lucas

:laugh:

The ground speed pump is a safety device. If the engine were to stall or quit for any reason, The ground speed pump provides oil pressure to safely get tractor off of road. It keeps steering and brakes working.
I don't know of any special tool to test transmission. Usually all testing is done while the transmission is in the tractor so transmission pump is turning to provide operating pressure. I am sure that facilities that are in business to rebuild transmissions do have tooling to run the transmission pump for bench testing purposes.

HI:fed:laugh:
I didn't get answer because i was busy. But I want to thank you for your engagement- jd110 you were right in 1000%. The ****... dumper made this leaks of. If i had listened you before i will save money. This dumper simply pull the flywheel hub out. Many thanks form Poland for this.
Greetings:fed: Lukas:lol: