torch
Well-known member
Equipment
B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
Sorry, which spool valve? The one controlling the 3ph or one of the FEL control valves?Torch, honestly I can***8217;t remember as it happened so fast but the pop may have occurred right as I first activated the spool valve.
That may be the key clue here. If someone went to all the trouble of making their own home-made banjo bolt, then what else might they have done to McGyver this little Frankenstein?If you look back towards the beginning of this post, you will see that goofy banjo connection at the 3 point connection that used to send pressure into my loader spool valve, along with a power beyond connection.
Here's the thing: Kubota's "open centre" design requires that the 3ph spool valve dumps the fluid flow back into the reservoir whenever it is in neutral. That prevents any meaningful pressure rise ANYWHERE else in the system while the 3ph spool valve is in neutral. If one simply taps into the "high pressure" line to supply fluid to the FEL spool valves, one will never get any pressure in the FEL hydraulics.
The ONLY way to get pressure in the FEL hydraulics is to interrupt the flow to the 3ph spool valve. That's what the direction control valve in the hydraulic block does -- it closes off a passage between the FEL supply port and the PB port, forcing fluid to the FEL control. The FEL spool valves direct that fluid back to the 3ph circuit if and only if they are both in neutral.
Opening the direction control valve opens a passage that bypasses the FEL completely. It's purpose is to supply fluid to the 3ph on tractors that have no FEL. If one was to close it with the FEL ports plugged off, the system would be deadheaded at the hydraulic control block, causing pressure to rise until something blew.
So, I believe that someone must have reworked things at the 3ph end to perform the function of a closed direction control valve. I don't have a B8200. I have never worked on a B8200. I don't have the FSM for a B8200. This is all a thought excercise for me. But looking at the hydraulic piping parts diagram:
I don't see this unpainted mystery fitting on the diagram:
1: if that mystery fitting was removed, would the banjo bolt you bought secure the original painted line to the casting?
2: Is the home-made banjo bolt hollow all the way through?
3: If so, is the mystery fitting?
I strongly suspect that mystery fitting and/or home-made banjo bolt block off flow to the 3ph spool valve, and was the means that McGyver forced fluid to the FEL and back. I think -- in my long winded way -- this is what Wolfman was driving at, in his much more succinct way.
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