Third Function for B7800 with Backhoe

[captfrank]

While I wait for the Power Beyond Sleeve for the hydraulic valve on my B1750, I have decided to add the Grapple unit to my B7800 that has a removable backhoe attachment. Pictures and information below. Interested in direction.

1. Tractor is a B7800 with FEL and removable Backhoe.
2. When I remove the Backhoe, I turn the knob below the seat to switch to the three-point lift/hitch.
3. Plan is to install a Third Function to power the Grapple Implement on the front of the tractor.
4. The pump line goes provides input fluid to the hydraulic controller. A second line from the pump goes to the backhoe.

Can I just "T" the third function unit into existing lines? Which ones? What else do I need to know? I feel like I need to take a class in hydraulic control systems!

Frank

 

[North Idaho Wolfman]

No, the third function has nothing to do with the BH lines or switching.
And you can not tee any lines (besides the tank, but your not using that line for third function)

You will remove either the pump input line to the loader valve and take that line into the third function valve then back out of the third function valve back into the loader valve where you removed that line.
or you can do it to the output line that goes to the BH, same thing just reversed.

Sorry but someone has seriously misinformed you what that valve does.
It's not a switching valve, it's a drop speed valve for the three point.

 

[TheOldHokie]

Can I just "T" the third function unit into existing lines? Which ones? What else do I need to know? I feel like I need to take a class in hydraulic control systems!

Frank

The Basics

Your tractor has an open center hydraulic system. The pump continuously circulates oil in a loop called the NEUTRAL circuit.

The term NEUTRAL describes the center or neutral position of the control valves in the system. In the NEUTRAL position low pressure pumped oil enters the valve, passes through the open (NEUTRAL) passage in the valve, and then exits the other side.

All the control valves in the system are connected in series. The pump is connected to the inlet port on the first valve and the outlet port is used to supply the next downstream valve. The outlet port of the last valve in the chain returns the oil to the reservoir.

Really quite simple. Mull on that and get it firmly fixed in your head before asking your next question which I am dure is percolating right now.

Dan