|
|
Gibsonville, NC | On my 4455 I have lost power steering, breaks and svc’s are not working. Tractor still moves front and back, pto works, seat even still goes up when you start it. Hydraulic oil levels are fine. Could this be air in the front hydraulic pump or has the front pump quit? |
|
| |
|
se montana | Start by checking pump coupler, then destoke front pump,.
Then check pressures, go from there |
|
| |
|
S.E. Washington | It does sound like the front pump quit. Is it turning? I've seen stripped splines and a broken shaft, so check for those. |
|
| |
|
Gibsonville, NC | That key way on that little gear behind the transmission pump has already gone out twice before. But if I remember correctly when that happened the tractor didn’t move. Could this be the same problem? |
|
| |
|
Faunsdale, AL | You’re correct. When the trans pump goes out the tractor won’t move.
In your situation, I think you have pump output from the front pump, but very low pressure (just enough to raise the seat).
I’ve “fixed” several by destroking the front pump. One I checked pressure on had 400 psi at the remotes. Just too low to do anything much. Certainly no steering or 3 point.
Edited by ccjersey 5/14/2021 09:22
|
|
| |
|
Gibsonville, NC | How do you destroke it? |
|
| |
|
Gibsonville, NC | Yes it’s turning |
|
| |
|
| . |
|
| |
|
Faunsdale, AL | If it has a screw already installed, simply turn it in with tractor engine running and then back out again.
If you look at the parts diagram of the front hydraulic pump on JD parts website you’ll see the plug with the screw in it shown at the top of the stroke control housing. It goes into a port on the top left corner of the pump. So it should be visible inside the left radiator screen below the fuel tank. If there’s one installed. If not you should see a flat hex head plug there that would be removed (engine stopped) and replaced by the manual destroking screw.
RE13271 should be a hex head or AR96625 should be a T style screw. |
|
| |
|
WCIN | Just wrapping up a 4440 that stripped the splines on the pump. Same symptoms. I know it’s 40 years old but I wonder if the hub dampener coming apart had something to do with it.
 (6028EA6F-39BA-4BBF-B3C2-646ECEDB4242 (full).jpeg)
 (C6AFF3A8-7595-41B8-AAB4-FB2E0B25D4F7 (full).jpeg)
 (9F979033-86DA-485F-87D3-636CC82730FD (full).jpeg)
 (97772EE4-7345-480F-A348-2A8C6CB718BC (full).png)
Attachments
----------------
 6028EA6F-39BA-4BBF-B3C2-646ECEDB4242 (full).jpeg (127KB - 73 downloads)
C6AFF3A8-7595-41B8-AAB4-FB2E0B25D4F7 (full).jpeg (114KB - 63 downloads)
9F979033-86DA-485F-87D3-636CC82730FD (full).jpeg (136KB - 75 downloads)
97772EE4-7345-480F-A348-2A8C6CB718BC (full).png (213KB - 90 downloads)
|
|
| |
|
Minot ND | sounds like the priority valve, on the three point housing, as your standing on the back of the tractor, on the right side where the main pressure comes in that fitting is the priority valve, you will probibly have to replace it. |
|
| |
JD 4455 hydraulic problems
