JD 3120 front axle leak and brakes not working

[jonnysteals]

I ahve a 2008 JD 3120 with only 350 hours on it. It mainly used as brush hob but gets used around the house. A few months ago I noticed the brakes are not working. It hasn't been a big deal with the hyrdostatic trans but I would like to trouble shoot it. Any known issues with these tractors? Can I use regular DOT break fluid? if it is low/has air?

The second issue is the front axle leaks fluid. It weaps from where the front knuckle attaches to the axles. These look almost like unimog portal axles so I am not familiar at all. Can you replace this seal? It looks like on the bottom of the knuckle there is a cover. I am assuming there is bolt under there to remove the knuckle. Any procedure / guides on how to replace the seal between the knuckle and the axle or can I just pop that lower cover off the knuckle and tighten the bolt some. I dont have any clue is this is correct or feasible as I am familiar with Dana 60 and such. If I pop that lower cover off will I lose fluid? What do you torque that bolt too if there is a bolt to tighten. Any insight/help with this would be greatly appreciated.

Thanks in advance. Im rather mechanically inclined but a tractor newbie.

 

[varmint]

Don't know anything about Deere's, but I believe pretty much all CUTs don't have separate braking circuits- if wet brakes, they would be in the hydraulic fluild, if dry brakes, then nothing. We're talking mechanical linkages here, jonnysteals.

 

[toolbox5]

those axle seals are a pain in the arse ! you basically have to disassemble all of it to replace the seal ,mega snap rings too , if I have to do it again ill pull the tire and the 4 bolts then take it to deere . youll have to drain the axle tube with the plug on that lower portion . good luck never had any issues with my brakes other than sticking

 

[joecdeere]

you need to do some reading, I have a PDF of the Tech manual you're welcome to, please take the time to look it over.
Shoot me your email if wanted

Joe

 

[GManBart]

Keep in mind that sometimes the reason the seals fail is that a bushing, king pin, or ball joint is starting to fail, and it allows the axle to move up and down, which ruins the seal.

 

[DLTTrekkers]

Brakes
The brakesisteme is a selffilling siseem.......if the correct gasket was fitted.
The bleednipples is on your rearfinaldrives and looks like a oversized zerk......remove it and clean them .......put it back and open it........start your engine and work your brakepedals till all the air is out them close the bleedingscrews. The pedals should be hard with very little travel.
If not.......you will have to do the padel adjustment......there should be no freetravel on your pedals ........to adjust .........unlock nut on adjusterbolt and turn out to no freetravel plus 1/3 turn more. Lock that nuts again!
Now move pedals slowly down and if they move all the way down ......you have a leaking valve in the mastersilinder that you will have to replace .

 

[jonnysteals]

Sorry for the delayed response. It never showed me any responses to the thread. Are these axles problematic? I just been topping off the fluid for now but would like to fix it correctly. DLK thanks for the brake info. Nothing is leaking from the rear so hopefully just some air or adjustments. Joec I sent you a Pm for the tech manual. Hopefully the manual covers adding a rear hydro because thats on my list so I can get a grapple.

 

[Dutch445]

johnny does the brake pedal feel like it's depressing properly? any way you can have someone depress
the brake while you watch the linkage going into the side of trans housing? there can be issues with that
brake shaft seizing up going thru that case, sometimes a little tap with the hammer to get it moving
then some repeated motion to free it up is all it needs...