Questions about by-passing a valve...

[/pine]

I know this looks cut and dried as a no brainer but I would like to have experienced advice...

...FWIW..this is in reference to a Ditch Witch 3610 W/ A322 BH...

I would (temporarily) like to remove the valve pictured below from service...

It seems I should be able to just attach the "T" line currently on the valve to the pressure QD and completely remove the valve??

The two spools operate the 6-way blade (BH station)...there is another set of valves at the drivers station to operate the blade...what need I do to with the function hoses?

This valve is first in line from the from the pressure QD...the tank line goes to the main backhoe spools...

 

[oldnslo]

/Pine,
From what you are describing I agree that connecting the valves existing tank directly to the pressure line would bypass this valve. As far as the function hoses they will have to be capped off if you are wanting to totally remove the valve from the machine.

 

[muddstopper]

Forgive me If I am wrong, but doesnt that machine use a 2 section pump with flow combined thru that valve. I think this was done so that if using 2 functions at once, such as dipper boom up and swinging at the same time, you wouldnt see a slowdown of either function. I think to remove the valve, you would have to provide a return to tank for which ever section of the pump you choose not to use.

 

[/pine]

Forgive me If I am wrong, but doesnt that machine use a 2 section pump with flow combined thru that valve. I think this was done so that if using 2 functions at once, such as dipper boom up and swinging at the same time, you wouldnt see a slowdown of either function. I think to remove the valve, you would have to provide a return to tank for which ever section of the pump you choose not to use.

Thanks for the replies...

muddstopper...you raise a good question I don't know the answer to...any suggestions?

 

[J_J]

If you remove the first valve, then the pump hose should go to the first operational valve IN port.

Just cap off the removed return port.

 

[/pine]

If you remove the first valve, then the pump hose should go to the first operational valve IN port.

Just cap off the removed return port.

You mean if I leave the valve where it is?...what if I want to remove the valve from the machine for a while...

(there's more to my intentions but they are not germane to my primary question(s)...will have more ?'s as I progress...)

 

[J_J]

Open center or closed center?

You can remove the valve or leave it in place.

Just re-route the pump supply to the intended valves IN port. Ensure it has a relief valve.

If the hyd system is closed center, just cap off the hose to the IN port and the return port hose.

 

[/pine]

Open center or closed center?

Don't know for sure...assume they are closed center...
again...there is a second set of valves that control the same cylinders...

How can I check and what do I do with the function hoses?

 

[J_J]

In a closed center hyd system, all hyd valves are in parallel. You can remove a valve and cap the hoses that you removed from the valve.

In an open center hyd system, you can remove any valve, and reconnect the supply hose for a complete flow path.

If the only valve you have left is the BH valve, then the pump hose will go IN port of the BH valve.

We don't have the full story yet, so it is difficult to provide exact answers.

 

[muddstopper]

Here are a pic of the pump and the valve I believe are similar to what you have. These came off a bigger ditchwith with a A620 backhoe so they might not be the exact same. The pic of the pump shows 2 suction ports and 2 pressure ports. One section of the pump I believe is 11-12gpm and the smaller section is around 7-8gpm. Both pressure lines from the pump connect to the valve, before going to the backhoe valve body. Both pressure sides of the pump go to the BH valve body and both sections are returned to tank from the bh valve body thru this same valve you are wanting to remove. To me this suggests that if you disconnect this valve, you wont be able to simply cap a few lines. Both pressure lines from the pump will have to have a path back to tank. It only takes 4 bolts to remove the bh attachment and thats why it has QC on the hoses.

I dont know what reason you are wanting to remove the valve, this would make your backhoe unusable and to do that simply set the backhoe off where it would be out of the way . I would then just get some more QC and hook what ever it is you wanting to hookup directly back to this same valve. Also,and I aint 100% positive, but I believe the pump for the backhoe only runs the backhoe and isnt connected to any of the other ditchwitch components, but you had better ask a ditchwitch mechanic to be sure.

 

[/pine]

Thanks for the information muddstopper...

The two spool valve is the BH station controls for the 6-way blade (below the BH)...currently one of the spools does nothing but opens a relief valve...the other spool works...when I got the machine both were very stiff ...I have not tried to troubleshoot what is wrong with the spool that does not work...

At any rate...There is little need for the blade controls at the BH station...I really don't need them or would really only want the up/down function (no use for tilt/pitch when using the BH)...the driver station controls for the 6-way blade all work as they should...

What I would like to do is use the second spool for a hydraulic thumb on the hoe bucket...

I need to continue using the BH and I thought if I could remove the valve (temporally)...inspect/clean and repair or replace...at my leisure...while still being able to use the BH...

Thanks for all the replies am open to comments and suggestions...

 

[muddstopper]

Starting to understand what you are trying to do. I am pretty sure the control valve for the BH does have power beyond capability. It would be very simple to just add a single spool valve after the BH control valve to operate your thumb. Just remove return line from BH control valve and hook to new single spool valve on tank side. Connect a hose from Bh PB port to new thumb control Pressure port. Run lines from new valve to your thumb cyl and your in business. Do it this way and if you want to set the Bh attachment off, you can still set it off as a single unit without having to replumb or cap a bunch of aux hoses.

Went and took a few pic of how I used a ditchwitch control valve and added another valve for my wood splitter. The first pic is of the ditchwitch valve. The line on the extreme left of the valve is the PB/Return to Tank port. This line is connected directly to my splitter valve pressure port. The next pic is of the wood splitter valve where I attached the line from the ditchwitch valve. Third pic is of both valves as they are now mounted on my splitter.