case 550E lt dozer won't move

This message is a reply to an archived post by AJ. on May 27, 2016 Just a side note I had a slow leak on the Steel fill line
that would drain the hydraulic oil over time. Before I fixed it, I would just add
oil to it and run it for several months until it was low and then add
more oil to it, until one day it ran it low while on a slope and dozer
wouldnt move. So I added more oil to it, which was too much but I
was able to get it on flat ground. The funny thing about it is all the
hydraulics for the blade still work. Just the travel is the problem.
So I draining the oil and fix the steel line problem and i reinstall
the oil thats when I noticed the problem with the travel
reoccurring of not moving, it seemed like it would only pull on flat
ground, but didnt really have a whole Lot of power pulling. I
started thinking it was something else so I pulled the pressurized
filter housing apart Thats under by your feet and found a blue
plastic cap that was stuck in the line and very distorted with
pieces of it missing. thought for sure this was my problem. But the
problem still there where it would pull when I first started it up
and the oil is cold. I havent tried purging the air out because I was
told from Case i didn t have to do that. Some have said the torque converter, but I was waiting to try the simple things first. Any help would be appreciated. Dually

The equipment hydraulics are seprate from the transmission, the hydraulics has its own reservoir the hydraulic tank, the reservoir for the transmission is the transmission case, you need to find the suction filter on the line between the transmission case and the torque converter housing, the transmission pump is on the inside of the torque cover and can only be accessed by removing the cover, check to see the suction filter is clean, check the suction line for any damage or any place it maybe drawing air, leave the filler loose in case the breathers are blocked and creating a vacuum, if all that checks out the pump would be suspect but before going there have a mechanic check things for you.
AJ

Im having the same issue, but my dozer will not move in any gear any direction. The manuals I have dont have drawings or photos that show enough information. I do know that the hydraulics for the blade are separate, and it works. The manual I have says that pressure for the drive and converter comes from the transmission. Before I start removing covers, does anyone have photos with covers removed, and maybe some descriptions of whats what? I have tried to find a mechanic to take a look, but their commercial work puts me on a very long waiting list.

Thanks in advance.

Is your dozer a Case 550E as well or some other model? It is always best to start by giving the manufacturer and model number, not just saying my dozer. What do you have for manuals?

What is the transmission oil pressure showing, what happened your tractor, was it playing up for a while or was it sudden, is the shaft between the torque and tranny spinning when in neutral, watch it and then put it in drive, make sure the inline suction filter is clean, all the details of rebuilding a Case are in the manuals, look in the index for power train and then torque and charge pump, there is no point in replacing parts unless the parts have failed and are the cause of the problem, Case like Cat are not known for giving presents.
AJ