Advice needed on adding hydraulic circuit

[JohnDB]

I'd like to add a bale clamp on the front end loader of my M4500DT. Currently it has one one-way valve, and one two-way valve both used for the front loader (single acting lift cylinders and double acting curl cylinder). So I need to add a two-way valve for the double acting bale clamp but I'm not sure of good options for doing this despite having done a bunch of internet searching. The hydraulics are open circuit, 2700 psi max.

I'd prefer to keep this old beast looking original so my first choice would be to add a second Kubota 2 way valve in the current 2-valve bank. But according to my research I can't stack a third valve onto the existing 2 valves (the existing 2 way valve is sandwiched between the one-way valve and the gearbox casing and the ports don't look like they are compatible with stacking valves).

Another other option seems to be to add a mechanical joystick for the loader controls but I am uncertain about the terminology and do not want to end up getting the wrong one, so I am calling for help!

Does anyone have any suggestions or can refer me to any sites about whether:

(a) a mechanical (non-electrical) joystick is available that will do 3 functions (single acting lift, double acting curl, and double acting clamp) all in one joystick? If so, what's the terminology for such a thing so I can find it on the internet?
(I don't need a float function but would be happy to have it. My only objection to electrical joystick is the additonal complexity. I'm reasonably confident that I can mount the mechanical joystick where the plumbing won't get in the way.)

(b) how do I plumb the joystick into the existing system so I can still use the existing 2 valves for other functions without having to isolate the joystick from the 2 valves, not have a separate supply and return line? Would I have to make a power beyond adapter?

Thanks in advance for your help.

 

[North Idaho Wolfman]

Clarity please...

Are you using a stock stack valve that would normally be used for the rear remotes to run the loader?

As far as a Loader valve with a manual 3rd function, they make them, but with a single acting dump cylinder it might not work correctly.

https://www.surpluscenter.com/Hydra...PM-Joystick-Loader-Valve-w-Grapple-9-8217.axd

 

[JohnDB]

Hi Wolfman - yes the loader currently uses the 2 stock valves that are mounted on the RHS of the transmission casing.

That joystick combo looks ideal. Forgot to mention earlier that the pump capacity is 7.3 US gpm (27.5 litres/min) so will check compatibility.

Not sure if I've interpreted you correctly, the lift cylinder (raise/lower) is single acting, the curl cylinder (dump cylinder) is double acting. I guess the same caveat applies though - in that I need to work out if the joystick is compatible with single acting lift cylinders.

I'll post some photos later this evening.

Thanks for your input

 

[JohnDB]

Top view of existing valves - one-way valve closest to camera. This valve has the built-in relief valve.

 

[Michael In Tennessee]

Worst case, use a diverter valve off the curl circuit. It will do what you need without screwing up anything on the tractor. No my preference as it's not as intuitive as a true 3rd function, but given what you are starting with it might be best.

 

[North Idaho Wolfman]

If you did get a new that Joystick valve it would change everything, yes it would work with you gpm wise, it's actually too big but there are limits to what's available is that style of valve.

Again the only issue might be the single acting lift cylinders.

if you wanted to go with the three handle version you could do it much cheaper, but that's not an upgrade.

 

[JohnDB]

Worst case, use a diverter valve off the curl circuit. It will do what you need without screwing up anything on the tractor. No my preference as it's not as intuitive as a true 3rd function, but given what you are starting with it might be best.

I hadn't thought of a diverter valve on the curl cylinder circuit. Thank you.

If you did get a new that Joystick valve it would change everything, yes it would work with you gpm wise, it's actually too big but there are limits to what's available is that style of valve.

Again the only issue might be the single acting lift cylinders.

if you wanted to go with the three handle version you could do it much cheaper, but that's not an upgrade.

Thank you. Assuming the single acting cylinder thing isn't an issue, then if I want to retain the use of the existing valves (for other functions) and hitch hydraulics can I simply insert the joystick supply into the current supply, so the return from the joystick becomes the supply for the 2 existing valves (and the hitch hydraulics inside the transmission)? (Something tells me I can't... it's too simple).

Or would I need a power beyond adapter between the existing valves and the transmission, so the pressure flow went through the 2 existing valves, to the adapter (feeding the joystick) and then to the 3 pt hitch?

Thanks for your help.

 

[North Idaho Wolfman]

Thank you. Assuming the single acting cylinder thing isn't an issue, then if I want to retain the use of the existing valves (for other functions) and hitch hydraulics can I simply insert the joystick supply into the current supply, so the return from the joystick becomes the supply for the 2 existing valves (and the hitch hydraulics inside the transmission)? (Something tells me I can't... it's too simple).

Or would I need a power beyond adapter between the existing valves and the transmission, so the pressure flow went through the 2 existing valves, to the adapter (feeding the joystick) and then to the 3 pt hitch?

Thanks for your help.

Easiest way would be to put the loader valve in the beginning of the circuit and leave the existing valves for rear use.

Break and remove the connection (#20) and put new end on the lines at the blue and red points, blue would be the power to the new Loader valve and red would be the power beyond back the the rest of the hydraulics, so get a power beyond sleeve/adapter for the new Loader valve.
You would add/make a tee that would fit into the suction line (Green), and that will be the return/tank port,
That's as easy as it gets.

 

[JohnDB]

What a cunning solution! Thanks so much for taking the time to explain that. I'll find out if the joystick can handle a single acting cylinder.

 

[Fedup]

Simple solution for a single acting cylinder. The valve has two work ports. Plumb one to the lift cylinders. Plump the other to a tee into the sump return. That way your double acting valve will not build pressure while you lower your loader, effectively making it a single acting valve.

 

[JohnDB]

Simple solution for a single acting cylinder. The valve has two work ports. Plumb one to the lift cylinders. Plump the other to a tee into the sump return. That way your double acting valve will not build pressure while you lower your loader, effectively making it a single acting valve.

H'mmm, will that arrangement mean that on lowering the single acting lift cylinder, all system pressure gets dumped to the return, so I can't use any other function at the same time - e.g. curl?

 

[North Idaho Wolfman]

Simple solution for a single acting cylinder. The valve has two work ports. Plumb one to the lift cylinders. Plump the other to a tee into the sump return. That way your double acting valve will not build pressure while you lower your loader, effectively making it a single acting valve.

True, but I wouldn't let it free flow, I would use some form of regulation to slow the drop speed down.

That valve also has its own pressure relief valve in it so it would also do it.

So with those two pieces of info, yes you should be able to safely use it on a single acting cylinder.

 

[JohnDB]

.
...
That valve also has its own pressure relief valve in it so it would also do it.

So with those two pieces of info, yes you should be able to safely use it on a single acting cylinder.

Aha, so if the joystick has its own pressure relief valve, it would be safe to plug the work port that would normally go to the lowering side (I forget the correct word) of a double-acting lift cylinder? So system pressure would be maintained?

 

[North Idaho Wolfman]

Aha, so if the joystick has its own pressure relief valve, it would be safe to plug the work port that would normally go to the lowering side (I forget the correct word) of a double-acting lift cylinder? So system pressure would be maintained?

Yep you got it, and then if it was lowering too slow, which by the schematics on the valve should not be an issue, you could always do as Fedup pointed out and add a drain loop in.

Worst case scenario (and not very likely), you would have to change to dual acting cylinders, and that's not that expensive.

 

[JohnDB]

Thanks very much guys, I appreciate you giving up some of your Friday morrning to help.

 

[JohnDB]

Thanks very much guys, I appreciate you giving up some of your Friday morrning to help.

All hail to the forum! Reporting back... you guys were a great inspiration.

Can't believe that it's 2 years since I kicked this project off! Well its done and it works brilliantly, can't keep the smile off my face when I'm using the joystick for the loader, got the 3pt hydraulic bale feeder running, and able to adjust the feeder angle with the hydraulic top link. I'm happier than a dog with 2 tails

Basically followed Wolfman's plan, and more advice over many months on the details of hooking up the 3 spool monoblock control valve from FedUp, thank you both so much.

A couple of thoughts if anyone else is contemplating this (adding extra valves to an old tractor)
1. The hydraulic system doesn't have high delivery ( 7.3 US gpm = 27.5 litres/min) but it doesn't matter, it's enough to do everything I need, I don't need the loader to lift any faster, or the bale feeder or top link to operate quicker. The valve itself has a 40 litre/min rating, and the controls are consistent and nicely modulating even though its rating is about 50% more than the pump - assuming the 40-year old pump is still delivering rated flow.
2. Cost - I assumed the valve would be the expensive part, but at least for this project, the hoses, fittings, and adapters were the biggest cost by far.
3. The more double acting spool valves the merrier... I'm already at the max using 4 (original on the tractor, plus added 3 in the new monoblock valve). But the limitation is how much space all the hoses take up, I'd have a hard job plumbing up a 4th spool if the monoblock had one. (I'm not counting the single acting valve also original piggy-backed on the tractor, but I may use it for raising/lowering the hay mower). I got an engineering drawing of the valve before ordering to make sure I could fit it and the hoses where it was most convenient to use. I made a rough cardboard-box mockup to check ease of access to the levers, avoid it impeding access to the seat and other controls.
4. I used 1/2" hoses and fittings everywhere because according to the hydraulics design guides I had seen, the flow rate was at a mid point between 3/8" and 1/2". So I went for 1/2" because I thought it would flow better. It also made fitting all the hoses into the limited space more challenging.
5. Although the loader lift rams are single acting, it was easy to plumb the system to work with the double-acting valve as per Wolfman, the only difference from his suggestion was that I plumbed the surplus outlet into a spare return line port on the valve itself (the odd-looking loop tube on the valve below the joystick).
6. Hydraulic top link was an afterthought because I had a spare circuit (I decided not to get a FEL bale clamp, instead I got a 3ph bale handler/feeder), and the hyd top link is really (as everyone says) a huge help, I wouldn't do without it now. Great for attaching gear to the 3pt, levelling the load on the rear up or down hills, raising the drag boom, making the rear blade more effective and adjustable. I got one that had the longest travel possible (250mm/10") for the relatively short overall length and I'm glad I did. Some hydraulic top links don't offer much travel at all, not good value.
7. I'm on a limited budget and it's an old tractor, so rather than invest in expensive equipment locally or from US I bought almost all the components from China. I was prepared to expect problems but the quality was great (I've been using the new hydraulic system for a few months now and wanted to see how it performed) in all but one case, and with that I had a refund within 24 hours of applying for it, and didn't have to return the faulty goods. But it took a lot of time to find suppliers (there is no one supplier that sells everything you need), establish a level of trust in their product, and describe what you want with absolute unambiguous clarity including images or drawings, and always show good manners (as we all should ). So definitely buy from your local supplier if you want prompt delivery.

Again, thanks heaps for your help.

Hoses have been oriented to minimise rubbing. Some look like they are contacting the handbrake and footplate but they have a few mm clearance. I'll keep an eye on them but I think they'll be fine for a few years yet.

Rear remote mount looks dodgy but is surprisingly firm and works well. I probably will replace it with something better... one day.

Hoses for loader - one for single acting displacement type lift cylinders, 2 for double acting bucket cylinder.

 

[TheOldHokie]

All hail to the forum! Reporting back... you guys were a great inspiration.

Can't believe that it's 2 years since I kicked this project off! Well its done and it works brilliantly, can't keep the smile off my face when I'm using the joystick for the loader, got the 3pt hydraulic bale feeder running, and able to adjust the feeder angle with the hydraulic top link. I'm happier than a dog with 2 tails

Basically followed Wolfman's plan, and more advice over many months on the details of hooking up the 3 spool monoblock control valve from FedUp, thank you both so much.

A couple of thoughts if anyone else is contemplating this (adding extra valves to an old tractor)
1. The hydraulic system doesn't have high delivery ( 7.3 US gpm = 27.5 litres/min) but it doesn't matter, it's enough to do everything I need, I don't need the loader to lift any faster, or the bale feeder or top link to operate quicker. The valve itself has a 40 litre/min rating, and the controls are consistent and nicely modulating even though its rating is about 50% more than the pump - assuming the 40-year old pump is still delivering rated flow.
2. Cost - I assumed the valve would be the expensive part, but at least for this project, the hoses, fittings, and adapters were the biggest cost by far.
3. The more double acting spool valves the merrier... I'm already at the max using 4 (original on the tractor, plus added 3 in the new monoblock valve). But the limitation is how much space all the hoses take up, I'd have a hard job plumbing up a 4th spool if the monoblock had one. (I'm not counting the single acting valve also original piggy-backed on the tractor, but I may use it for raising/lowering the hay mower). I got an engineering drawing of the valve before ordering to make sure I could fit it and the hoses where it was most convenient to use. I made a rough cardboard-box mockup to check ease of access to the levers, avoid it impeding access to the seat and other controls.
4. I used 1/2" hoses and fittings everywhere because according to the hydraulics design guides I had seen, the flow rate was at a mid point between 3/8" and 1/2". So I went for 1/2" because I thought it would flow better. It also made fitting all the hoses into the limited space more challenging.
5. Although the loader lift rams are single acting, it was easy to plumb the system to work with the double-acting valve as per Wolfman, the only difference from his suggestion was that I plumbed the surplus outlet into a spare return line port on the valve itself (the odd-looking loop tube on the valve below the joystick).
6. Hydraulic top link was an afterthought because I had a spare circuit (I decided not to get a FEL bale clamp, instead I got a 3ph bale handler/feeder), and the hyd top link is really (as everyone says) a huge help, I wouldn't do without it now. Great for attaching gear to the 3pt, levelling the load on the rear up or down hills, raising the drag boom, making the rear blade more effective and adjustable. I got one that had the longest travel possible (250mm/10") for the relatively short overall length and I'm glad I did. Some hydraulic top links don't offer much travel at all, not good value.
7. I'm on a limited budget and it's an old tractor, so rather than invest in expensive equipment locally or from US I bought almost all the components from China. I was prepared to expect problems but the quality was great (I've been using the new hydraulic system for a few months now and wanted to see how it performed) in all but one case, and with that I had a refund within 24 hours of applying for it, and didn't have to return the faulty goods. But it took a lot of time to find suppliers (there is no one supplier that sells everything you need), establish a level of trust in their product, and describe what you want with absolute unambiguous clarity including images or drawings, and always show good manners (as we all should ). So definitely buy from your local supplier if you want prompt delivery.

Again, thanks heaps for your help.

Hoses have been oriented to minimise rubbing. Some look like they are contacting the handbrake and footplate but they have a few mm clearance. I'll keep an eye on them but I think they'll be fine for a few years yet.
View attachment 75894

Rear remote mount looks dodgy but is surprisingly firm and works well. I probably will replace it with something better... one day.
View attachment 75895
Hoses for loader - one for single acting displacement type lift cylinders, 2 for double acting bucket cylinder.
View attachment 75896

I must say that is some neatly executed plumbing using the proper fittings and excellent placement of the controls.

Dan

 

[JohnDB]

I must say that is some neatly executed plumbing using the proper fittings and excellent placement of the controls.

Dan

Thanks, yes it works well.

 

[North Idaho Wolfman]

Excellent to hear!

 

[JohnDB]

Excellent to hear!

Thanks Wolfman