Kubota MX4800 3rd function - roll my own - check my work

LD1 · Dec 3, 2018

NPT + aluminum block + 545 loctite sealant......and not something that is gonna be put together and taken apart over and over again = no worries.

I too dislike NPT, but sometimes its unavoidable. Valves or cylinders that are difficult to source with anything but NPT.

Only thing to do is immediately adapt to JIC and go with it.

Michael In Tennessee · Dec 3, 2018

I agree that I'd use a NPT - JIC fitting and go from there. Hoses will be JIC. The far end, I see no other option but NPT. So, a JIC bulkhead fitting through a shop made bracket with the far side NPT for the QDs. An ORB or JIC Quick Disconnect is a rare bird.

/pine · Dec 3, 2018

LD1 said:
Why do you say the NPSM fittings are cheaper?

Everytime I have compared.... they are the same or a mere pennies different

I just did a quick comparison and the mechanical swivel fittings/adapters are about half the cost of a crimped hose end fitting for 90's, 45's etc...the savings increases even more so the larger the size...of course they are reversed...i.e., the 90*. 45* is part of the fitting/adapter and not the hose...
IMO the biggest benefit is how easy it makes ordering hoses...nothing but straight pipe hose ends...(30* inside chamfer)...which also makes them simple to install...

Not NPSM but angled ORFS swivel nut adapters are about one third the cost of angled crimp on hose fittings...

Granted...sometimes they swivel nut fittings can take up a bit more room than male adapters on smaller valves etc...but IMO they really make things easy

LD1 · Dec 4, 2018

/pine said:
I just did a quick comparison and the mechanical swivel fittings/adapters are about half the cost of a crimped hose end fitting for 90's, 45's etc...the savings increases even more so the larger the size...of course they are reversed...i.e., the 90*. 45* is part of the fitting/adapter and not the hose...
IMO the biggest benefit is how easy it makes ordering hoses...nothing but straight pipe hose ends...(30* inside chamfer)...which also makes them simple to install...

Not NPSM but angled ORFS swivel nut adapters are about one third the cost of angled crimp on hose fittings...

Granted...sometimes they swivel nut fittings can take up a bit more room than male adapters on smaller valves etc...but IMO they really make things easy

I wasnt suggesting getting hose ends with the 90* or 45*

Still using hoses with straight ends. And separate adapters for the angle change.

But instead of NPT hoses.....use JIC hoses.

And using those adapters that go from whatever to a JIC as opposed to going from whatever to NPT

Hiptfarms · Dec 4, 2018

Just out of curiosity, how much will you wind up saving over buying a "kit" from some supplier versus putting this together for yourself? I'm thinking of adding a grapple to my M6800 that has a Bushhog brand quick attach (M446 - now obsolete) and being as cheap as I am, I think I may go the long lines from the remotes on the back of the tractor instead of adding a 3rd function kit. (Of course I also have to adapt the grapple to fit my FEL.) But depending upon how much savings there is, maybe i can swing it.

ericm979 · Dec 4, 2018

The commercial kit that a lot of people use (the name escapes me at the moment but EA sells them) is around $800-850. The joystick knob with switches can vary quite a bit in price. The OP's project should cost less than half of that commercial kit, depending on the hoses.

Hiptfarms · Dec 5, 2018

Around half off - nice!

N2DFire · Dec 6, 2018

MtnViewRanch said:
As far as the DO3, plate, I think that I mentioned something about drilling the ports out also?

I suppose that it wouldn't make much difference if you were a person that didn't use much more than 1/2 throttle most of the time. What I do know is that I have seen a 16GPM aux valve burn up a 17GPM pump. I had a customer that burned up 3 pumps on an MX5100, which turned out to be a flaw in the internal plumbing of the tractor's main case.

These failures ended up costing a lot of money and time for something that should have been easily avoidable if the proper parts would have been used.

If you are a person that uses their equipment pretty much to max more than half of the time, these small under sizings can make the difference between longevity and equipment failure.

Just my :2cents:

Sorry so long to reply back - I have been out of the office on training for the past couple of days.

I see the logic behind what you're saying. Esp with the max usage scenario.

Thanks for the explanation. :thumbsup:

Michael In Tennessee · Jan 13, 2019

Back from Vacation (can you take vacation from retirement?) and ready to work this in earnest.

I found a rear ported 3/8 NPT D03 plate on e-bay. With that, I can use straight NPT to JIC fittings, which means no issue clocking NPT fittings. I still hate NPT, but it seems the path of least resistance. I checked the tractor and there are no clearance issues using a rear ported subplate. Mounting will even be straightforward. My mount plate just has to have holes in it for the rear ports. I probably have to buy a hole saw of the correct size, but no big deal. I can't order the subplate until Wednesday since the e-bay seller is on vacation. Also no big deal.

I'm still working out the control switch. I think I'm going to adapt a UTV winch/snowplow knob. I have the control relays. I'll need to buy some proper automotive wire in a couple of colors.

Question: In which forum should I post my build? This one? Kubota? Hydraulics?