john deere 4475 hydraulic issues

[petrojoe]

hello all, while running my1998 john deere 4475 skidsteer today it started to lift slowly and finally i have no lift or tilt at all. i checked the oil and it was ok started machine back up and when i went to move it it dosen't want to move very well and is noisy like the hydro unit is starving for oil any idea's??? i found a pump online that mounts by the foot controls is this the main pump that controls everything-hydraulics and drives?

 

[antfarmer2]

If it was sudden check and see if the aux hydro is stuck on solinoid or valve

 

[jerry]

If it was sudden check and see if the aux hydro is stuck on solinoid or valve

If the coupling to the charge pump broke it would act like that so do not run it at all till you find out. With no charge pump you would quickly starve the hydrostatic pumps. I would not run it at all till you make sure the hydro pumps are getting charge oil.

 

[jerry]

If the coupling to the charge pump broke it would act like that so do not run it at all till you find out. With no charge pump you would quickly starve the hydrostatic pumps. I would not run it at all till you make sure the hydro pumps are getting charge oil.

Looked on the deere parts site and you have a gear pump first in line and two piston hydro pumps in line behind it. Lift the seat and you will see this arrangement. The charge pump is the one first in line and supplies the cylinders with oil and feeds the hydro pumps make up oil. You should check that gear pump out first , might have to take it right off to do though.

 

[petrojoe]

Looked on the deere parts site and you have a gear pump first in line and two piston hydro pumps in line behind it. Lift the seat and you will see this arrangement. The charge pump is the one first in line and supplies the cylinders with oil and feeds the hydro pumps make up oil. You should check that gear pump out first , might have to take it right off to do though.

Jerry, when you say first in line is that from the motor, or toward's the pedals?

 

[jerry]

Jerry, when you say first in line is that from the motor, or toward's the pedals?

It is first in line from the pedal end.

 

[jerry]

It is first in line from the pedal end.

go to this site
http://www.deere.com/wps/dcom/en_US/parts/parts_by_industry/commercial/commercial.page
then pick search for parts , enter your model #, select powertrain and then centering mechanism.

 

[jerry]

go to this site
http://www.deere.com/wps/dcom/en_US/parts/parts_by_industry/commercial/commercial.page
then pick search for parts , enter your model #, select powertrain and then centering mechanism.

or this,http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.HomePageServlet_Alt
I have no idea why the link is not live.

 

[jerry]

or this,http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.HomePageServlet_Alt
I have no idea why the link is not live.

http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.HomePageServlet_Alt

 

[petrojoe]

http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.HomePageServlet_Alt

thank's for the info, I took the charge pump off and took it apart to discover catastrophic failure,driven gear shattered and broke the drive gear so I ordered a complete pump assembly

 

[jerry]

thank's for the info, I took the charge pump off and took it apart to discover catastrophic failure,driven gear shattered and broke the drive gear so I ordered a complete pump assembly

Be sure to change any filters and try to flush any downstream lines so no debris goes into the hydro pumps.
I don't know why the deere parts site is so hard to navigate now. Used to be able to just search for john deere parts but now to get the schematics I have to go down to a site titled construction equipment parts.