JD 550 transmission issue

[Jeff550c]

I recently purchased this John Deere 550C Dozer. I believe its a
good 1975. Anyways, been going through it to make sure all is
good. When originally checking the transmission was low on
fluid. (I have changed all the filters). I drove it around for a few
hours. Everythings works perfectly. I then noticed a leak
coming from the cap on the right side brake housing. It appears
to now be over full. Im thinking there is a line or passage thats
filling in and its not able to get back out. I did read in the
manual about converting to a common sump. Looking for some
on-site on how this works and what I should do to repair.
 

[Jim.ME]

I expect you have a straight 550 with a 6405 blade (that is the meaning of the C). They did not build a C series, they went from 550B to 550G, no C, D, E, or F.

When you say cap on the right-side brake housing are you referring to the cover plate? Or the pipe plug on the side of the steering clutch housing behind the sprocket?

What manuals (publication numbers) do you have?
 

[Jeff550c]

Sorry, you are correct it's a strait 550. I keep referring to the C designation on the SR#. Yes, the oil is coming out of the cover
plate. the oil is also leaking out around where the shaft goes through to engage/disengage the brake. I have the JD 550 TM-1108. This in
only happening on the right side. Thanks for any help you can provide.
 

[Jim.ME]

You are likely going to have to get into it to find the problem. It doesn't seem the common sump conversion would be the only issue if it is not happening on both sides. Leakage from the steering clutch or supply hose to that clutch would be the probable cause of extra oil going into that compartment. Another possibility is the cover gasket is bad and the seal on the brake shaft has worn or torn, and you are seeing some leakage from splash.
 

[Roy Suomi]

The steering clutch manifold is leaking to clutch housing sump and with no where to go, It overfills the housing. You can do a quick fix by removing the return oil hose and leave it out. That will allow the oil to go back to transmission to be reused. early 450-C's had the same problem..
 

[Jeff550c]

Thanks for the feed back. I ended up pulling the cover from the right side and found a bad hose. This has been replaced and dozer holds pressure at 250 psi. Now the issue is once it runs for quite some time the pressure starts to drop to the bottom of the green. Im thinking the oil is getting hot and loosing c
Viscosity. The tranny temp switch doesnt work yet. Looks like its time to pull the bottom pan to check and replace if needed. Any suggestion on loosing pressure after running for some time?