Help ordering hydraulic fittings (for rear remote)

[rswyan]

OK it's labeled "PB" you can see it in the pic.

Got it now - the "PB" is partially obscured by the rubber cap for the hydraulic coupler in the picture.

This could be the case. What problem does this cause?

Just a guess on my part:

It could cause damage to the functionality of the valve ... perhaps even including catastrophic failure of the valve's casting.

I dunno how likely the latter is, but if a manufacturer states that the pressure at the valve's return port shouldn't exceed a certain value (500 psi say), like J J has said, there's probably a valid reason for it.

Given the location of the valve (right next to the operator's station) the possibility exists of getting sprayed with hot hydraulic fluid, if not actually hit with flying metal.

 

[rswyan]

I don't know. Only recall one in the middle of the tractor but I will look again.

See the picture of the installation instruction for the rear hydraulic block I attached in post no. 19 - which shows the rear hydraulic block, and it's location on the tractor.

In the lower right corner of that picture, there is an illustration of the rear hydraulic block itself.

Is a "block" just a simple "connection block"?

Yes.

Does it have other functions inside (check valves etc)?

No.

 

[rswyan]

Sodo,

I'm going to give you the flow path for your machine based on what I see in the pictures which you have provided.

It will assume that you do not have the rear hydraulic block installed ... because based on the hose routing shown in the pictures, it appears that you don't.

It would also be helpful if we could see a side view (of the inboard side) of the Dinoil valve being used for your rear remotes - in order to determine whether the Dinoil valve is even power beyond capable. It appears to me that there may be a plug there ... which might be for a power-beyond adapter.

Also the model number of the valve would be useful ... but unless you have an invoice or instruction sheet for the Dinoil valve itself, you may not have a way to obtain the model number (slight possibility that there could be a sticker or label still on the valve)

Flow path:

1. Output from hydraulic pump ---> outlet on mid hydraulic block (internal on the tractor)

2. Outlet on mid hydraulic block ---> inlet on FEL control valve (external, via a hose)

3. Power beyond outlet on FEL control valve ---> inlet on Dinoil rear remote valve (external, via a hose)

4. Return (to tank/reservoir) on Dinoil rear remote valve ---> (power beyond) inlet on mid hydraulic block (external, via a hose)

5. (Power beyond) inlet on mid hydraulic block ---> 3PH control valve (internal on the tractor)

6. Return outlet on 3PH control valve ---> tank/reservoir (internal on the tractor)

It appears that the problem is at no. 4 above: return port on Dinoil valve being used for power beyond.

Additionally there is one line/hose running from the return outlet/port on the FEL control valve to the tank/reservoir port on the side of the tractor's case in the rear.

 

[BukitCase]

Here's some stuff that may help - (NOT specific to your Kubota)

hydraulic supermarket | technical library

More to the point -
How to configure mobile hydraulic valves using power beyond

As already mentioned, most hydraulic valves, either stacked (modular) or monoblock (what you bought is what you got, period) do NOT like to see more than typically 500 psi in the Tank gallery - so when you're not actually using a valve, the flow from the pump just passes thru the valve galleries and back to tank.

The portion of the casting that has the tank port may(or may not) also have an OPTIONAL PB port - if that option is NOT installed, then the tank gallery and the PB gallery are all connected, and pressure in that section stays low and returns fluid back to the tank.

Without PB, the extra port (PB) is plugged with a standard pipe plug (usually) - In order to add PB to such a valve, you remove the standard pipe plug from the PB port and REPLACE it with a PB adapter - this is essentially a glorified THROUGH adapter - it has a hole clear through, and various output threads depending on the manufacturer/model -

The DIFFERENCE in this PB adapter, is it ALSO has a STEPPED outer body, with O-ring seals between the steps - when it is inserted into the PB port, the innermost O-ring BLOCKS the connection between Tank gallery (low pressure only, seals NOT designed for high pressure) and the PB gallery (made for high pressure) -

Here's the PB adapter for Prince Stack valves, showing the stepped outer sleeve and the O-rings that separate the two galleries

https://www.surpluscenter.com/Hydra...-BEYOND-SLEEVE-FOR-PRINCE-SV-VALVE-9SV-PB.axd

So NOW, with the PB adapter in place, if you don't move any levers in the valve body, flow ONLY goes thru the PB adapter and on to the next valve in line, and finally to tank. (still at high pressure, but ONLY if you're actuating a valve (to a toplink, for example) -

In a typical open center system, when you actuate ANY cylinder from ANY valve, flow is re-directed - either to the "A" or "B" WORK port - whichever port (A or B) is pressurized, the OTHER work port gets routed to the Tank gallery to relieve pressure on the other side of the cylinder's piston - otherwise, the cylinder can't move.

Without a PB adapter in a control valve, ALL the pump flow just goes IN the Pressure port and OUT the Tank port UNTIL you move a lever, and a gauge placed ANYWHERE in that path will only read as much pressure as would be caused by various restrictions in tubing, hoses, open valves, etc.

WITH a PB adapter installed, the TANK port only feeds back to tank when a spool on THAT valve is moved - otherwise, ALL fluid continues on thru the circuit thru the PB adapter.

Not sure I cleared up ALL your questions, but hopefully it's a start... Steve

 

[rswyan]

Ok, let's see if we can sort some of this out:

My FEL valve has a port labeled PB, and it goes to the yellow-banded line on the small block at mid-tractor.

Please recheck this ... if what you say above is true, then your FEL valve is also plumbed incorrectly (because the fluid supply from the tractor's hydraulic pump would be being fed - via the mid hydraulic block - to the power beyond port of the FEL valve, rather than the inlet port of the FEL valve - that's backwards)

The line from the forward port on the mid-hydraulic block should go to the inlet of the FEL valve.

The line from the port labeled "PB" on the FEL valve should go to the inlet of the Dinoil valve.

 

[BukitCase]

Found this, don't remember where I got it - Steve

Oh, even though PB and IN are reversed I'm not sure it would matter since the PB adapter makes those two ports CONNECTED to each other, but NOT to the Tank port??!?

 

[rswyan]

Found this, don't remember where I got it - Steve

Good stuff.

Oh, even though PB and IN are reversed I'm not sure it would matter since the PB adapter makes those two ports CONNECTED to each other, but NOT to the Tank port??!?

Interesting point

 

[J_J]

BukitCase

The diagram you posted is correct.

The PB floe from the FEL is going to the new valve IN port and the PB from the new valve is going downstream.

If he did not use the the optional rear hyd blk, then the FEL flow would go to the IN port of the three spool valve and the PB flow from the three spool valve should go back to the hyd blk and the flow will continue to the 3pt.

All tank lines go to tank period.

 

[Sodo]

Thank you guys so very much.

RS I'll take your flow path and follow it, see if it looks right. I like the image Steve, will put it on my phone.

I understand this much better now, and when I go out to my tractor this weekend I'll follow the hoses & get it right. Will be there for Mem day weekend. If anyone can find a good schematic of what my system ought to be, that may help too. Sure hope I can add PB to the Dinoil, if they are $18 & a hose that doesn't hurt much (and do I have to add the rear Hydr block too?)

 

[rswyan]

Thank you guys so very much.

RS I'll take your flow path and follow it, see if it looks right.

I'll be awaiting your report.

I understand this much better now, and when I go out to my tractor this weekend I'll follow the hoses & get it right. Will be there for Mem day weekend. If anyone can find a good schematic of what my system ought to be, that may help too.

I'll have a look in my Kubota Workshop manual ... not sure, but it may cover the B2710 as well as the B2910/B7800.

Sure hope I can add PB to the Dinoil, if they are $18 & a hose that doesn't hurt much ...

You'll need one more item (see below)

(and do I have to add the rear Hydr block too?)

No you wouldn't have to.

You could just run a hose from the (new) power beyond outlet on the rear remote valve to the power beyond inlet on the mid hydraulic block. Basically just move the hose that's attached to the return port on the rear remote valve now to the new power beyond outlet on the rear remote valve.

Then pick up a hose to run from the return port on the rear remote valve to to the tank/reservoir return port on the side of the tractor.

Then you add a JIC run tee to the tank/reservoir return port on the side of the tractor (to allow connection of two return hoses - the one from the FEL valve and the one from the rear remotes)

Possibly this one would work (the exact fitting or fittings depends on the clearances you have to work with and what thread connection you get on the new hose):

https://www.surpluscenter.com/Hydraulics/Hydraulic-Adapters-Fittings/JIC-to-JIC/JIC-Male-to-JIC-Female-Swivel-to-JIC-Male-Run-Tee/JIC-6M-x-JIC-6F-SWIVEL-x-JIC-6M-RUN-TEE-9-6602-6-6-6.axd