Adding FEL hydraulics to Kubota L3301

[Fallon]

Yes & no, the loader valve has some slightly different internal plumbing so it can operate both spools at the same time, but not that unusual. And it has a relief valve that will open the start of the power beyond loop to the tank/out port when pressure gets to high. It's not that much more complicated than other valves.

#1 correct, kind of. If you want to add another valve before you existing relief valve (loader valve) you need to put in another relief valve.

#2 You can add additional valves anywhere along the power beyond loop. Just hook the IN port to the pump or the PB port on the upstream valve. OUT is dead fluid that can't do any work except go back to the tank, PB is fluid that will power the next valved in the loop. The last valve in the loop dumps their PB to the tank, same as out. The 3pt is almost always the last valve in the loop in tractors.

A solenoid might actually be the easiest to do & get what you want, depending on where you put it. If you put a pair of solenoids on your bucket lines, that would get things done. Your loader control would operate normally for lift & curl. Hit solenoid button & then it kicks the solenoids over to the 3rd function. Your curl function would then operate the 3rd function, with all the feathering ability you currently have. You couldn't use the 3rd function & curl at the same time, but get the other benefits.
http://www.tractorbynet.com/forums/hydraulics/189835-third-function-valve-verses-diverter.html

General links:
http://www.baumhydraulics.com/files/infobuild/terms_hydraulic_control_valve.pdf
http://www.tractorbynet.com/forums/hydraulics/116052-what-does-power-beyond-really.html

 

[Fallon]

http://www.tractorbynet.com/forums/hydraulics/268367-third-function-preference.html

 

[Scott65]

Ok guys, thanks for all the wonderful info. I've made a few decisions, nothing I can't go back on in the future. But for now I've gone ahead and ordered a directional control valve, and the accessory PB plug to go in one of the ports. So that presents 2 more questions for me. This valve has its own pressure relief. I would assume that simply "maxing out" this relief would be the easiest way of ensuring that it doesn't interfere with the factory preset relief valve. But if I don't have to mess with it, its that much easier. So my first question, if its set lower than the factory one, does it affect the entire system? Lets say for instance, if the factory is set to relieve at 2000 PSI and this aftermarket valve is set at 1500, will my FEL and 3 point now have a safety release of 1500PSI?

Second question, is there some sort of size guide to determine what type, size, thread, etc of fittings I've got and need so that I can order my hoses from one of our vendors here, instead of having them made locally for a premium $? I'm a diesel mechanic, I can tell you about a nut or a bolt by feel, with my eyes closed. But I have no clue when it comes to these hydraulic hose ends.

Thanks!

Edit:
Sorry, third question. I was going to just match the hoses I have on my L3301. They are engraved 3/8's on all the FEL hoses. I just looked at Discount Hydraulic Hoses and they offer internal or external diameter. So my Kubota hoses, is the 3/8 marking referring to ID or OD?

 

[Fallon]

1) The pressure relief valve will function between the pump & whatever spool is closed upstream of the valve. If you add a 2nd pressure relief downstream of the loader valve, it will affect your new spools & the 3pt hitch, but not the loader valve. When you operate the loader valve, it cuts off most or all of the flow downstream in the power beyond loop.

2) I'm not a good one to ask, I had to re-order my hoses and/or some adapters in my learning experience. https://www.discounthydraulichose.com/v/vspfiles/downloadables/thread_guide.pdf might help. In theory the fittings on your tractor should be the same as mine, but I wouldn't bet the cost of a hose on it.

3) ID. If in doubt go bigger. Small hose will slow down your flow & heat the oil. Undersized hose can be fine in some areas, like to the TnT or grapple, as it slows things down, but definitely not ok in the power beyond loop. I actually have restrictors on my TnT cylinders that have a pin sized hole in them so you can get fine grain adjustments done & not move the cylinder several inches in the blink of an eye.

I'd recommend Brian (Mtn View Ranch on the boards) Fit Rite Hydraulics - fitritehydraulics.com good prices & quality gear. Might not be the fastest option all the time (he's a 1 man shop), but he has a very good reputation on these boards for being helpful as well as the product he delivers.

 

[Scott65]

Thanks Fallon. I read through that guide a little bit yesterday and I have thread gauges and calipers, etc. But I'm not sure where to start in that catalog, as far as what type of fittings. I know they aren't pipe thread, and I'm pretty sure they aren't o-ring, but not sure beyond that. But I'll keep looking around. I haven't gotten near close enough yet in assembly that I have to know just yet.

So it seems to me at this point that I can just max out the pressure relief that came in the directional control valve that I'm installing, therefor relying solely on the factory installed Kubota relief to continue protecting the entire system, including my added on plumbing.

And as far as hose sizes, thats good to know. I feel pretty confident that the 3/8 will be sufficient for supply and return (or however you look at it) to the cylinder or post hole digger motor that will be mounted up front. The factory power beyond hose from the loader valve down to the valve block beneath the drivers foot rest is 3/8's as well. But I'm thinking of mounting my new valve on the opposite side of the tractor to allow control of 3rd function at the same time as controlling the bucket, therefor adding quite a bit of length to that part of the power beyond circuit. So maybe I should bump that particular hose up one size? I assume it can't be too big, unless you go way overboard and the pump just can't flow enough gpm to fill the hose up?

 

[RandyHut]

My first post - I want you guys to know i got more from this thread about adding Hydraulics to my tractor than 2 hours of reading elswhere!!

 

[J_J]

Ok guys, thanks for all the wonderful info. I've made a few decisions, nothing I can't go back on in the future. But for now I've gone ahead and ordered a directional control valve, and the accessory PB plug to go in one of the ports. So that presents 2 more questions for me. This valve has its own pressure relief. I would assume that simply "maxing out" this relief would be the easiest way of ensuring that it doesn't interfere with the factory preset relief valve. But if I don't have to mess with it, its that much easier. So my first question, if its set lower than the factory one, does it affect the entire system? Lets say for instance, if the factory is set to relieve at 2000 PSI and this aftermarket valve is set at 1500, will my FEL and 3 point now have a safety release of 1500PSI?



I would set all the reliefs to the factory setting.

A valve set at 1500 psi, it will only affect hyd components downstream.

If the FEL valve is set to 2500, then the FEL cyl's will relieve at 2500 psi, and valves downstream will relieve at 1500 psi. .

 

[J_J]

Thanks Fallon. I read through that guide a little bit yesterday and I have thread gauges and calipers, etc. But I'm not sure where to start in that catalog, as far as what type of fittings. I know they aren't pipe thread, and I'm pretty sure they aren't o-ring, but not sure beyond that. But I'll keep looking around. I haven't gotten near close enough yet in assembly that I have to know just yet.

So it seems to me at this point that I can just max out the pressure relief that came in the directional control valve that I'm installing, therefor relying solely on the factory installed Kubota relief to continue protecting the entire system, including my added on plumbing.

And as far as hose sizes, thats good to know. I feel pretty confident that the 3/8 will be sufficient for supply and return (or however you look at it) to the cylinder or post hole digger motor that will be mounted up front. The factory power beyond hose from the loader valve down to the valve block beneath the drivers foot rest is 3/8's as well. But I'm thinking of mounting my new valve on the opposite side of the tractor to allow control of 3rd function at the same time as controlling the bucket, therefor adding quite a bit of length to that part of the power beyond circuit. So maybe I should bump that particular hose up one size? I assume it can't be too big, unless you go way overboard and the pump just can't flow enough gpm to fill the hose up?

Something you might not realize, is that a FEL valve ahead of a 3rd function could use all the flow and none left for the 3rd function.

Also, a 3rd function valve is full flow when switched on, unless the flow is regulated ahead of the valve. .

Trick is to use partial lever so some pump flow will continue downstream for other things.