[discobrian24]

Got an issue, my 400 wont move. My hyd levers do nothing aswell as my tractor will not go forward or reverse. I noticed a broken pin in the shaft on the engine so I replaced it. Wonder if the key on the tranny side is bad. I looked under tractor and while running the pump looks to be turning. The other weird thing is it will work fine one minute then the next time I start it it wont work at all. This is what has me confused. As of right now it is not working. Changed fluid and filter a few weeks ago, can an overfilled trans show these symptoms?? I am stumped.

 

[discobrian24]

To add steering doesnt work either. I am going to check the key in the trans side of the driveshaft as well as possibly change the fluid and filter again.. This is driving me bananas as before I dorve it on trailer it wouldn't work, then 10 min later when I started it up it did work and I drove it on the trailer. It will not be easy to get off trailer to fix as I have the box blade on rear and loader on the front... Why me??

 

[shivelyt]

It could be that the key on the tranny side is broken and is only turning the pump part of the time. It would be worth a look.
Tom

 

[jdalchemist]

Brian,
Either the driveshaft tranny side key or the shaft pin in the charge pump are likely the problem. Does the loader have its own hydraulic pump or have the tractor hydraulics been modified for loader operation? If the hydraulics are modified, maybe there is a problem with an added check or bypass valve, or an issue with hydro pump charge pressure.
Harold

 

[discobrian24]

Went and got new keys so I am gonna tear into her now. The loader runs off stock hydro. Thanks guys. I am leaning and hoping its the key as I can see where the shaft slid forward. It makes sense, sure it is turning but I bet not enough to work. Will let ya know!

 

[discobrian24]

Ok tranny key looks to be ok, Changed fluid over to Low Vis and added about 4 quarts and still nothing. How hard is it to change out the pin on the charge pump?? I have the manual just wondering what the best course of action would be next??

 

[discobrian24]

It almost looks as if this repair can be done with transmission still in the tractor if I am reading correctly. Is the pin you are talking about the pin that holds the Gerotor??

 

[jdalchemist]

Brian,
Yes, that pin locks the gerotor assembly to the tranny shaft. You will need a new o-ring and replacing the shaft seal would be wise. Be sure to note the orientation of the charge pump.
Harold

 

[discobrian24]

Ok thank you Harold. Not in a huge hurry to get this fixed because my mowing machine is my 332, but need to have it fixed before the snow flies. From what I see it may be easiest to pull the whole hydro out of the tractor to work on it on the bench, what do you think?

 

[inspired_metal]

Brian,
Are you the type of person that likes to do things the easy way?????????

 

[discobrian24]

I am the type that likes to do it the right way the first time. I am a mechanic on bowling machines so wrenching is in my blood. This tractor has a repower that I put in a few years ago.

 

[inspired_metal]

Good Answer.
It's usually faster to do it right once than to scrape your knuckles, bend and pry stuff to get it reassembled only to find that you need to take it apart further to do it right.

Well said.

 

[discobrian24]

Update, tested pressure on front ports and have no pressure. There is no where on the hydro to test pressure that I can see.

 

[jameszmcnelley]

HI Brian, On the RH side of the hydro unit, in front of the control shaft is a plug. you can get the same readings there that you would normally obtain at the disconnects.
I have a dash mounted gage on my 400 hooked up to this port, to keep tabs on the syst.
The port size is SAE M-4 with an O ring. later, JZM

 

[discobrian24]

Ok cool will look into it. I think I am just gonna pull the hydro this week and check the charge pump pin.

 

[discobrian24]

Where did you get the dash mounted guage and hose or did you have the hose made up for you??

 

[jameszmcnelley]

Brian, gage came from Speedway Motors. It has the port on the back, instead of the bottom. [bulkhead type]. You have to fab a retaining bracket. Most any 2 1/2'' rear port gage can be made to dash mount left of the factory key switch location.
I was never able to locate a 2 inch face version with a 1000psi range. I paid $40 for the gage mentioned because it had a RED needle and the face plate was a dead on match to the new Sun-Pro gages I was also installing. An inexpensive gage can be had for around $12.
Hose I had made with a female swivel JIC at each end.
You need a JIC-M to SAE-M CONNECTOR at the pump port mentioned earlier.
Then a JIC-M to JIC-F SWIVEL 90 degree ELBOW fitting.
That will connect the hose at the pump end.
To connect the hose to the gage, for the dash mount location mentioned earlier you need a JIC-M to NPT-F 90 degree ELBOW between the gage and the hose. The photo shows the location that works best. The gage in photo is not the Speedway version. I used an el-cheap O to fab up with.
[cant get photo to load, will log off and try again.] JZM

 

[jameszmcnelley]

HAPPY PLUMBING, JZM

 

[discobrian24]

Ok update here and on the John deere facebook page. The pin broke in the charge pump and did a little damage to the gearotor on 1 side. Now I don't know if it will work with a new pin or not. I also don't know the best way to flush out the hydro. Do I need to tear the whole pump apart?? I found 2 chunks of the broken pin when I took it apart.

 

[discobrian24]

Anyone source out a new Gerotor?? Anyone contact Sundstrand to see if they still make the part even though it is NLA through Deere??? I am at a standstill til I can figure out what to do.

Can you flip the Gerotor over?? If so that will change how it turns. All my damage is to one side. I may just try it.