Power beyond issues

[K5lwq]

Model RD5300 25 Gallon Three Spool

Model RD5300 25 Gallon Three Spool directional control valve

www.princehyd.com

Do you understand what is wrong? Ptsg and rScotty both have explained the correct way to plumb another valve.

 

[rScotty]

Do you understand what is wrong? Ptsg and rScotty both have explained the correct way to plumb another valve.

View attachment 768331

Thanks, K5lwq. It helps to know that Ptsg and I are making sense.

I think that 2011laramie will "get it" with another look. After all, he's showing the capped PB plug in his photos - so he is looking in the right place. All he needs to do is get the proper PB plug and be good to go.

BTW, that is an awfully nice picture of a control valve - both the original and with your notes. Neither Ptsg nor I mentioned that sometimes the PB "sleeve" we have been talking about is incorporated into the plug fitting itself. Looks like that is the case with this one.
Sometimes all the PB plug/sleeve options come with a control valve, but usually you have to specify the one you want and then can buy the others. Typically about $20 bucks. The problem is that they are specific to each model of control valve body. With any luck, 2011laramie got a box with them all in it.
rScotty

 

[s219]

I agree with ptsg too.

On Kubotas, the three point hitch always needs to be last in line on the PB loop. Anything you add needs to be inserted before the three point hitch and needs to not stop or divert flow when not in use. The hose block under the side of the tractor will have some pretty specific arrangements, but the quick suggestion is to understand how the loader is currently plumbed and then insert your new valves after the loader and before the three point hitch.

Right now the loader output goes into the three point hitch input port on the block. That is where you need to insert the new valve, between the loader output and three point input.

 

[Smokeydog]

The beyond port is capped, but not with the CC cap so it's an open center setup. The 2nd set of controls is for the down pressure kit which pushes on the 3 pt hitch arms.

Those els and maybe black iron nipples look suspicious like plumbing fittings on the lower valve photo. Made to tighten with pipe wrenches that bite into fittings. Hydraulic els are heavier body and have flats for smooth jaw wrenches. Threads are higher precision, stronger steel, much higher bursting strength and easier to tighten in tight spaces. Pipe, fitting, hose bursts are hazardous and could cause death. Even the smallest leaks are dangerous. Never check with your hands.

If in doubt, change it out.

Often on used equipment have to fix previous owners mistakes.

I would caution against using Teflon tape thread sealant on hydraulic systems. Hydraulic specific thread sealant is best.

Anything associated with trees is going to test your hydraulic system to the max.

 

[rScotty]

Those els and maybe black iron nipples look suspicious like plumbing fittings on the lower valve photo. Made to tighten with pipe wrenches that bite into fittings. Hydraulic els are heavier body and have flats for smooth jaw wrenches. Threads are higher precision, stronger steel, much higher bursting strength and easier to tighten in tight spaces. Pipe, fitting, hose bursts are hazardous and could cause death. Even the smallest leaks are dangerous. Never check with your hands.

If in doubt, change it out.

Often on used equipment have to fix previous owners mistakes.

I would caution against using Teflon tape thread sealant on hydraulic systems. Hydraulic specific thread sealant is best.

Anything associated with trees is going to test your hydraulic system to the max.

Whoa, good catch! I didn't even notice that. Lucky for him he didn't get it working. Black iron water plumbing fittings and teflon tape. Good thing you saw that.

Old timers got away with using a particular type of iron plumbing fitting because the tractors of 50 years ago ran 1000 to 1200 psi and it was possible to source plumbing fittings made from ductile black iron. That still wasn't safe or to spec, but it was common practice.
Now the psi in most tractor hydraulics is around 3000 psi and plumbing fittings are typically the more brittle cast iron rather than ductile (malleable) iron. I don't even know where to find ductile iron 3/4" ells locally.

I've refitted a few old hydraulic systems like that. SurplusCenter.com has good prices on hydaulic hardware & fittings. All 5000 psi stuff.
To get the teflon tape remnants out of internal threads I use a skinny brass bottle brush. Put it in the center of the internal fitting and then "unwind" the tape fragments just like withdrawing a tap. A dental pick helps too.
rScotty

 

[LD1]

The way it is currently plumbed, if I understand, is the way the backhoe is plumbed.

You are indeed going from loader>spade>3ph.

Nothing in this setup would prevent the 3PH from lifting IF it is indeed an open center valve.

Without being there and without seeing pictures of your exact hose routing.....sadly there isnt much we can do to help. But the fluid IS going somewhere. IF the tractor isnt laboring, it likely isnt going over the relief. So either something is plumbed wrong or????

But in anycase....just because the way you have it "should" still allow the hitch to lift....DONT. Because it still isnt right. Tank passages on cast iron monoblock valves is NOT designed to have any kind of back pressure. Yet that is exactly what you are doing by lifting a heavy tree spade that is fed from the tank ports of not 1, but 2 valves on that spade.

And whoever did the hack job of installing the second valve for the "downpressure" clearly has no clue about hydraulics. Black pipe fittings, and not even utilizing the power beyond of the valve before it. What make/model of tree spade is this? How did the previous owner use it? Did they have it hooked to a rear scv(remote)?

What you have now is a situation that is dangerous, incorrect, and can potentially cause costly damage to the tractor.

 

[Smokeydog]

What I have done is take the parts like the tree spade valve with the current fittings loosened to the hydraulic shop counter with sketch or pictures of what I need to do. They are good at mocking up with the correct fittings, adapters, and hoses that you may need. Couple of swivel fittings greatly adds to ease of install and future repairs. They have lots of experience and expertise making the adventure enjoyable and educational. Good shops have good customer service and want to earn your business now and in the future.

 

[rScotty]

What I have done is take the parts like the tree spade valve with the current fittings loosened to the hydraulic shop counter with sketch or pictures of what I need to do. They are good at mocking up with the correct fittings, adapters, and hoses that you may need. Couple of swivel fittings greatly adds to ease of install and future repairs. They have lots of experience and expertise making the adventure enjoyable and educational. Good shops have good customer service and want to earn your business now and in the future.

But it would just be dumb luck if they had the proper PB port plug/sleeve combo for that control valve. And that's what is needed.

 

[Tractor Seabee]

This problem is real simple. With the BH detached just use the same connections identical to the BH. The spade valve will then need a PB plug (if the manufacturer makes one) or a new valve with one and a connection fitting in the PB outlet.

PS. Here is where the shop manual for your tractor shines with its explanation of the BH and hydraulic system and piping diagrams.

 

[LD1]

This problem is real simple. With the BH detached just use the same connections identical to the BH. The spade valve will then need a PB plug (if the manufacturer makes one) or a new valve with one and a connection fitting in the PB outlet.

PS. Here is where the shop manual for your tractor shines with its explanation of the BH and hydraulic system and piping diagrams.

A backhoe loop is only a 2 line connection because you cannot use the 3ph while using the backhoe.

So yes, IF this tractor had a backhoe and backhoe loop, using those two hoses for inlet and PB would be fine but it would ALSO need a 3rd line added for a return to tank.

Without a 3rd line, and I'd imagine a quite heavy load on the 3PH....my guess is its gonna make a leaky valve on the tree spade with that much backpressure on the tank ports, or worst case, blow one of them black iron pipe fittings.