Hyd Gurus pls help - Backhoe hookup (3 hoses) how to plug ?

[rallyeracer]

Hi Guys,

I'm a bit 'new' to the tractor scene so I think I'll need help from hydraulic gurus here.
I have an older Oliver 550 (gas) tractor. Manual trans (not hydro) with hydraulic output for my FEL and Snowblower (chute)

The setup I have currently works fine. I have a joystick up front for the FEL that is fed from the pressure port of the tractor internal hydraulic system. Then, the outlet of the joystick (T) goes to the top of my rear remotes pack (4) to feed them so I can activate my SB chute. The outlet then goes to the tractor tank.

I recently bought a MF 1580 backhoe but it comes with 3 hoses. Upon inspection I have routed back the 2 colored codes hoses (red, yellow, blue) to the block valve and found out the the RED goes to the P port (pressure), the Yellow is on the T port (tank return) but the 3rd one, the BLUE one goes to a port not labelled.

I need to know how to hook this properly to my current system.

Note: On my FEL joystick, there is a N port that is not used.

I was initially planning to add a quick connect on a Tee up top my rear remote pack for the Pressure (P) and one on the bottom for the Tank Return (replacing the actual elbows for Tees to isolate the rear remote when the new Quick would be plugged). See last pic for my intended hookup. Advise if not done properly please !

I'm still in the vague for the blue line. This is where I need your help !

Thanks so much, I just doesn't want to break anything.

Id a picture's worth a thousand words then 6 should complete my explanations

Bye, Jason

 

[ericm979]

The BH valve stack might have both power beyond and tank ports. In that case the line from the PB port would go into the tee from backhoe port, which feeds the 3pt. And the other tank line would go directly to the tank or tee into a line that goes directly to tank.

You need documentation on the BH's valves so you can know for sure what the ports are.

BTW your idea of teeing into the lines going to/from the rear remote won't work. The fluid will bypass the BH valves when the cylinders are called on to do work. You need a valve in there. Or put a quick connect in line with the hose to or from the remote valve so you can unplug it and add the BH to the loop when it's on the tractor. Valves in open center have to be in series, not in parallel.

 

[rallyeracer]

the line from the PB port would go into the tee from backhoe port, which feeds the 3pt. .

Good but that part (quote) is the one I dont understand.

What do you mean about the "tee from the backhoe port" and my 3pt is internally fed.

Thanks for the cue againt teeing into remote. You are right it would not work.

Thanks, Jason

 

[ericm979]

Sorry, my writing could have been clearer. The 3pt is the last valve in the chain. The tank port from the current remote valve feeds it. Yea it's inside the cases but it's getting fed from outside. If you connect the BH after the remote valve, the BH's PB port would feed the 3pt.

I think that you can connect the BH either before the remote valve or after. Keep in mind that all the valves output ports, tank or PB, need to be able to support full system pressure if they are feeding another valve. PB ports should by definition. Valves with no PB only tank may have tank ports that can only handle 500 psi or so. It'll be in the manufacturer's literature.

 

[rallyeracer]

Hi Ericm979, thanks again for your help, i'm getting there !

Ok so here's what I would do then:
Tie the BH hydraulics AFTER my current remote stack, so outlet 'T' from the remote would feed the BH pressure line (RED - P), then the BH PB hose (the blue one I guess since the yellow is the Tank one) would go to the tractor return line where I had the remote return originally.

But then if I feed the BH PB hose to the return hose, where does the BH tank hose goes ?
In the same port I guess but if I route both to the return, I guess I need to come up with a sort of return line with a tee with 2 ends (1 for BH PB + 1 for BH Tank) AND add one-way valves to both to prevent back flow from either BH hose to the other BH hose (PB to T or T to PB). That way the Tank hose from the BH valve would not be fed too much pressure from reverse flow of the PB hose.

Please see attached pic.


My valve is very similar to this bradco one, which clearly shows the PB port.


-OR-

can I plug the PB port on the BH valve ? And only use the Tank hose to return to tractor ? (or the other way around, plug the T and use the PB) I know the PB is an option on this model (you remove the PB port plus to install a sleeve to have PB but I don't need it right ?

Sorry for asking a lot of questions, I'm still learning the ropes of this right now.

Thanks so much for the time you take to help me out. GREATLY appreciated !!

Bye, Jason

 

[ericm979]

If you want to not use the PB port you could remove the widget that enables it (it changes the flow inside the valve). You can't just cap it. BUT you need to make sure that the tank port can handle system pressure! Otherwise if you use the remotes or 3pt with the BH on you can damage the expensive BH valve stack. My BH is like that. Its limited to 500 psi. It's plumbed after my remotes (I use one to operate a grapple). I have to remove the 3pt arms to put the BH on so I can't use the 3pt for an implement and I probably can't load the 3pt cylinders enough to cause damage. But in any case I leave the 3pt position lever alone when the BH is on. If you put the BH after the remotes (verifying that valve's tank port can handle full pressure) then you'd be set up the same way.

The BH may work better when set up to have PB. There's a reason many loaders have PB. Maybe someone else knows what difference it makes, if any. All I can think is that the dedicated tank port (with PB) has less restriction than the common PB/tank that goes through more valves. If you do use PB then the tank line needs to be run into the tank. One way to do that is to tee it into the tank line from the loader valve.

 

[rallyeracer]

Well I just looked at the schematic of my valve and the PB port sleeve is optional. Otherwise, there is a plug (#8 ORBM) that seal that port. Both the Tank and PB hoses comes from the same 'block' of the valve (modular valve). Both are also the same sizing so given that I'm pretty sure the Tank side can accept the full flow/pressure.

Here's my valve


After capping the PB port (I was lucky to have the #8 ORMB plug), I hooked the remaining P and T hoses into one of my remote (by prior checking which one gives pressure when pushed) and tried a quick test to see if it would operate and it does.

Pushing on that remote lever gives me flow into and out the backhoe (and I still have 3pt control and loader too even if not needed). That would leave me 1 remote set for a hyd. thumb maybe.

I'm wondering if I could swap the Tank hose for the PB hose (in the remote ''return'') and tee the Tank hose to the outlet hose of the remote (with a check valve prior to the tee to protect tank side of BH valve)

Like this (see actual setup - working and what I could do to use the PB and protect Tank side of BH valve)



That way the PB is used and returned to tank/3PT and tank can drain too

What's your thoughts ?

THANKS !

 

[ericm979]

If it was me I'd do it without a check valve, which seems like a hack to avoid plumbing. You can run the tank line up to the loader and tee it into the loader's tank at the valve.

 

[rallyeracer]

Ok but if I do that (Tee into loader tank side) I would tap into pressure going to remotes.

My loader valve feeds the remote from it's T port as it should.

Wouldn't that push pressure into the backhoe valve tank side ?

 

[rallyeracer]

I probably edited my post when you were replying.

I added that pic of actual setup - working and what I could do to use the PB and protect Tank side of BH valve