Hello......I have a 1985 jd 490 where one of my final drives is filling up with hyd fluid and pressurizing, and I assume its gonna be a blown oil seal. Does anyone know how big of a job this is gonna be. Is it as simple as possibly pulling just the motor off and not having to remove the whole drive? Thanks in advance
Good day Common cause is excessive case drain pressure caused by filter blockage hope it helps. Kind regards Uffex
Ok I'm going to try to locate the filter and check, but the seal should be replaced correct?
Good day Jason Yes I would replace the seal and filter check that the pressure in the case drain is low I should point out a motor failure can also be the culprit so check for unwanted stuff in the main filters.I will check the files to see if we can help with better information. Kind regards Uffex
Hi Jason Please see attached hope it is helpful Kind regards Uffex
Attached is a 450 pump house you can see the filter blue
Could be case drain pressure from the motor but a leaking swivel can push drive loop oil into the case drain and pressurize it also. How many hours are on it?
I would say that it's more than likely your brake seals leaking, be careful with that final drive, they are next to impossible to find anymore. I've seen a number of 490/120 Hitachi machines parted out for lack of a good final drive.
A digger of that age you would have to assume there will be alot of wear in the travel motor rotating group which causes the seal to blow.
I'm gonna tear into it tomorrow guys, it has around 8k hours and I will update thanks
Good day Fresh from the press may be it will help you. Kind regards Uffex
Thanks uffex
I know this is a old post I have the same 490 doing the same thing were you able to fix and where did you get seals thanks
Is it a 490, 490D or 490E? either way it should be available from Deere.
490 here doing the same. What was the fix?
I have a 1988 490. It also was leaking hydraulic oil into the planetary gears in the final drive. Thank you excavator for your suggestion about brake piston seals. I replaced them and the leaks have stopped. Incidentally my machine has 27000 hrs on it and the final drives look as good as new inside.
Welcome to HEF Alan King . You have any pictures of the ol girl ?
Good day everyone I have a 1985 jd 490 I recently just had both drive motors rebuilt because they where both leaking hydraulic oil out of the planetary. After reinstalling both nee rebuilt motors on leak is gone one leak is not. It is leaking hydraulic still out of the seal between the drive gear and the case. Do I need to send the motor back? Because it seems there should not be more hydraulic leaking if my motors all have brand new seals.
Welcome to HEF Treeman . See the attached screenshot. There is a brake piston#7 and spacer # 10 in the bore of the final drive housing that needs to be resealed . Just need to remove the motor to access the brake piston and spacer. https://partscatalog.deere.com/jdrc/sidebyside/equipment/64700/referrer/navigation/pgId/692 .
Is the 490D John Deere excavator final drive the same as the 690D
I highly doubt it. FWD
No . Deere has a good online parts lookup site https://partscatalog.deere.com .
I checked they no longer have any information on 690D or 490 D
They use the same part number for floating seal on final drive th100463
John Deere still has information on 690E and 490E but the part number is different so I guess they changed something
What all do you need for the 690D final drive ?
Looking to reseal brake piston and drive seal
I did find parts brake down on JD site thanks Diesel Dave it kept telling me that my search was not valid but some how I was able to find the information
Did the final drive overfill with hydraulic oil and pushed out the duo cone seal at the track drive sprocket ? On a 690D the brake piston is internal to the propel motor. You may get away with just changing the propel motor shaft seal to take care of the hydraulic leak assuming the motor performance was good.
It was good and yes it started slowly then now leaking bad l figure checking the motor and brake seals as soon as I can get my hands on parts
I would like to thank Diesel Dave for the advice it is going to help I just have to get the parts now.
Hello again well I changed seals on drive motors I checked for excessive oil on motors had them free flow into bucket both did not seam to have excessive amounts of oil flowing from motors and return hoses replaced both return filters cleaned rock filter on pilot system changed filter on tank pressure relief valve still having trouble blowing seals going to check return screens in hydraulic tank and then I guess the rotary manifold seals may take a while had to go back to my regular job