John Deere 855 power beyond hydraulic problem

deerestalker · Jul 12, 2018

Looking for some help. I purchased an earlier model JD 855 that had a Loader and no. 7 backhoe. I removed the backhoe and power beyond kit and plugged the two PB ports with o-ring boss plugs. Problem is tractor three point does not work. I see in other posts concerning PB that there is a diverter plug. Is that my problem that the fluid is being diverted past my three point? If so where is this plug located? Thanks for any help.

beenthere · Jul 12, 2018

ROCKSHAFT HITCH WILL NOT LIFT
1. See 湧o Hydraulic Functions.
2. Auxiliary hydraulic jumper hose not installed or plug not removed.
3. Stop valve closed.
4. System relief valve setting too low.
5. Load too great.
6. Implement relief valve setting too low or valve leaking.
7. Rockshaft piston scored or seals leaking.
8. 100 mesh screen between rockshaft control valve and rockshaft housing plugged.
9. Unloading valve stuck open.
10. Rockshaft spool valve scored or seals failed.
11. Flow control valve stuck open.
12. Lower valve stuck open.
13. Lever linkage bent.

From the service tech manual.. and you may have diagnosed the problem.. i.e. the plug per #2

Mechanos · Jul 13, 2018

deerestalker said:
Looking for some help. I purchased an earlier model JD 855 that had a Loader and no. 7 backhoe. I removed the backhoe and power beyond kit and plugged the two PB ports with o-ring boss plugs. Problem is tractor three point does not work. I see in other posts concerning PB that there is a diverter plug. Is that my problem that the fluid is being diverted past my three point? If so where is this plug located? Thanks for any help.

Why did you remove the power beyond kit? If you just connect the two ports together with PB hose, it will complete the circuit and everything will function as it should. Then when you want to reinstall the backhoe (or any other PB device) just disconnect the hose and route it through the attached device. What you have done is deadhead the hydraulic circuit and put the whole system into relief until you either complete the PB circuit, or remove the diverter plug.

kennyd · Jul 18, 2018

If you blocked the two ports after removing the hoses, then your tractor is in relief whenever it's running and you can overheat the fluid and/or damage the pump. You will need to remove the "plug" #19.

AUXILIARY HYDRAULIC KIT
Cart key PART NO. PART NAME QTY SERIAL NO. REMARKS
1 38H1314 Elbow Fitting 2
2 R26448 O-Ring 2
3 T77857 O-Ring 3
4 AM105111 Hydraulic Cylinder Cap 1
5 AM105468 Oil Line 1
6 M72810 Label 1 (E)
M76402 Label 1 (F)
M93620 Label 1 (G)
7 AM105469 Bracket 1
8 24M7051 Washer 1 21 X 37 X 3 mm
9 T78716 Nut 1 20.625 mm
10 AM105465 Hydraulic Hose 1 INCLUDES A CLOTH SHEATH AND A 90 DEGREE BENT STEM
T13119 O-Ring 1 INTERNAL
11 R26375 O-Ring 2
12 AM105467 Hydr. Quick Coupler Plug 1
13 AM105466 Hyd. Quick-Connect Coupler 1
14 M42702 Snap Ring 1
15 AM105470 Oil Line 1
16 AM105464 Oil Line 1
17 T77613 O-Ring 2
18 PT13744 Plug 1 DIVERTER
19 BM16762 Kit 1 600001 - 610000 (655)
BM16762 Kit 1 800001 - 820000 (755/756; 855/856)

Nick359 · Jul 22, 2018

I tried to swap a power beyond from a 755 to a 955. I sold the 755 and kept the backhoe for the 955. There is a plug that needs to be removed, I wish I could tell you exactly where. The plug is 8mm or 10mm allen head that needed to be removed. You have to take a bunch of stuff off to get to it. The problem I incurred was the previous owner put green thread lock on the plug on the 755 tractor. I could not remove it. Since its on a hydraulic valve, I did not want to heat it. I ended up buying hose to "loop" the power beyond on the 755. I had to buy the 8mm or 10mm allen head plug to put on the 955. The plug was around $1 and the hose to loop it on the 755 was around $100. It was cheaper than the $300 JD wanted for the new power beyond kit. If I remember correctly there was a cap somewhere under the seat that needed to be removed to take the "plug" out.

The you have to take a bunch of stuff off includes the seat and rear fenders. I remember this because my dog fell through the ice on the creek out back and drowned. I had to put the 755 back together enough to get the backhoe operational so I could burry her.

Mechanos · Jul 23, 2018

Someone posted this annotated picture several years ago... I can't remember who for proper credit, but I saved it and just ran across it. This picture shows the location of the diverter plug access plug. You first remove this plug, then reach inside this hole to another socket head plug. This internal plug is the diverter plug. With no diverter plug, there is no power beyond circuit. With the diverter plug, hydraulic oil is routed through the external power beyond lines and back into the machine on the other side of the diverter plug.