What am I going to break?

[jdbower]

After a few months of playing around, I think I'm nearly ready to hook up my first hydro project, but I'd like a sanity check just in case. The goal is to add two spools to the rear of the tractor and to use the Power Beyond port to power it. The valve I bought was oversized, I brought the PB ports from 3/4" down to 1/2" and the output form 1/2" to 1/4". Before I add Loctite 545 and tighten everything down, have I made any obvious mistakes? The extra hydro ports are to control the mower lift and a hydraulic toplink today (which is why the levers face opposite directions), who knows what I may add in the future.

Does this look like it should work or am I missing something big? I did check and it's an open center valve - when I blow into it without the QDs connected air goes through no problem.

 

[RonMar]

So the hose on the inlet port comes from a PB outlet on another valve? I se you are using a QC on the return port on the valve in your picture. Where is that one going to go to?

As long as that return port with the QC is a low pressure path back to the reservoir, then I see no problem with your configuration. That prince valve has a 500 PSI limit on the return port backpressure. As long as the return path dosn't exceed that(no other valve circuit downstream), or you don't inadvertently disconnect that QC(put a zip-tie around the sliding collar on the QC, or remove the QC and hard plumb it in place) then I don't see any problem with what you are planning.

I probably wouldn't have used locktite on the pipe fitings, hydraulic oil rated pipe dope would have worked and sealed just fine.

 

[jdbower]

Thanks! I feel much better now that someone has blessed it - depending on whether my answers raise another gotcha.

I've got a loop on my PB port most of the time, I intend to move this loop to the sleeve side of the QA shown (although I think I've got them reversed, I'll have to check to see if the nipple or the sleeve end of the QC is the fluid source/sink) and run the hose back to the PB port to complete the PB loop (the hose pictured has a nipple on it who's too shy). In short, hose from the PB goes into the input, hose out of the valve goes back into the PB port. I intend to bypass this valve when the backhoe is on - not much chance of mowing or needing the hydraulic toplink then.

The Loctite 545 is (I think) mostly a hydro sealer (although I have a morbid fear of using any Loctite in a red container!). I'm open to other brands if you deem it a more wise decision.

 

[Soundguy]

I agree with ronmar... the only issue I see is that return line and a QD... Chinese tractor owners know what happens when qd's get pulled when they are not suposed to.. Hopefully.. your tractor relief is ahead of this.. if not.. make absolutely sure that qd ont he return is always maintained open and seated.

Ditto with the oil rated pipe dope.. I just got done installing a dual spool valve on an old ford.. most of the fittings were pipe thread except for the valve itself which was ORB.. ( which i converted to pipe.. in order to have the same type fittings everywhere..).. I used an oil rated dope, and none of my fittings even seep...

Also.. those qd's that are long due to bushing-down.. watch them.. don't knock them off.. it will make quite a mess..

Soundguy

 

[RonMar]

depending on whether my answers raise another gotcha.

I've got a loop on my PB port most of the time, I intend to move this loop to the sleeve side of the QA shown (although I think I've got them reversed, I'll have to check to see if the nipple or the sleeve end of the QC is the fluid source/sink) and run the hose back to the PB port to complete the PB loop (the hose pictured has a nipple on it who's too shy). In short, hose from the PB goes into the input, hose out of the valve goes back into the PB port. I intend to bypass this valve when the backhoe is on - not much chance of mowing or needing the hydraulic toplink then.

You have me a little confused about your plumbing. What do you mean by "loop" on your PB? The way I am reading this, the input port(one with hose and shy nipple) for the valve you pictured in the first post is comming from a power beyond output on another valve on your tractor(loader valve perhaps?). This PB line already has QC's on it and it is how you power your backhoe? Where does the other line from the PB or return from the backhoe when attached, go to on the tractor? Is it to another valve such as the 3PH control, or does it flow back to the reservoir unrestricted?

If it runs back to the resovoir, you are fine with this plan and the way you have it plummed(providing you have the QC's right).

If there is another valve downstream on that PB line, then you will need to change your plan a little bit by adding a PB sleeve to your pictured valve, move your QC with the elbow to that PB outlet port and add a dedicated low pressure/non restricted return line from the return port(where the elbow and QC are now attached) to the reservoir.

 

[jdbower]

Maybe I'll have to grab more pics when it's light out again. The bottom port of my PB coupling is hard connected to a short hose (2' or so) at the rear of the tractor. This hose has a nipple on the end and plugs into the top port which is a sleeve QD. Normally these mate up in a simple loop, or they connect to two QD hoses on the backhoe. I'll be going from the fixed PB hose into the sleeve end of the QD pictured and the valve's hose (also with a nipple) goes back to the PB return (again, pending verification of the reversal issue). Since there's nothing else on the PB circuit that I know of it sounds like I should be OK until I need another set of connections. I'm not touching the FEL connectors for this setup - in fact the primary function is to get the mower off the FEL SCV.

Normal:
PB Source --> PB Return

Backhoe:
PB Source --> BH Input --> BH Output --> PB Return

New setup:
PB Source --> Valve Input (Sleeve QD) --> Valve Output (Valve Hose) --> PB Return

If I get another valve inline on the PB path it sounds like I may need a Power Beyond Sleeve? From the diagram it seems like the PB output of the valve would be plumbed to the next valve and the outputs both sent back to the reservoir.

Biggest issue (besides checking the plumbing to see if my assumptions on directionality are correct) seems to be making sure the PB QDs are tight. The valve should be fairly well protected where it will be mounted so hopefully the long "drop side" QDs will be OK. I will check out Lowes for some more generic hydraulic rated thread sealant.

 

[RonMar]

Sounds like you have the plumbing into this valve figured backwards. That larger overall pic you posted shows the hose connected to the valve inlet port(it even says IN right next to it). The elbow and sleeve QC are connected to the Low Pressure return port. As a rule, the inlet port on most valves is near the safety relief.

Here is a link to the instruction sheet for the 5000 series valve you are using.

http://www.princehyd.com/Portals/0/products/valves/RD5000InstS.pdf

You will probably need to follow the plumbing for that PB return port on your tractor to confirm that it goes unobstructed to the resevoir. If it goes to another valve or the possiblity exists that you will put another valve downstream of this one, you will need to configure this valve for PB and add a dedicated return line to the reservoir. There is a diagram on the second page of the linked file that shows your valve configured for PB with another valve downstream.

 

[jdbower]

As I suspected, the PB hoses are plumbed directly into the pump so I should be fine. In typical modern documentation style I can't quite figure out which port on the pump is source and which is sink so I've asked the Deere guys to see if they know. If my assumption is correct that the PB hose is pressure then I do indeed have it backwards - if only Deere would put a big IN and OUT on their PB mounting bracket for me like Prince did. Maybe I should try to find some purple hydro fluid so if the Prince valve leaks I get Purple Rain

 

[jdbower]

...if only Deere would put a big IN and OUT on their PB mounting bracket for me like Prince did.

You ever have one of those days where you realize you need to pay a little more attention?
http://www.tractorbynet.com/photos/data/527/28619DSC3959_Small_-med.JPG

I actually chose wisely the first time. I gave it a quick run after the last part (a JIC to NPT converter) came in today and the tractor still works fine with it installed (at least the 3PH raises and lowers and the engine doesn't bog down). The two cylinders I wanted to control with it open and close in a reasonable amount of time (not too fast, only slightly slow on the toplink but I dropped down the hose size from recommended). I found and fixed three leak points even without a thread sealant.

Once I fab a mounting bracket I'll post some pictures and parts lists for those interested. Thanks again for the sanity check before I took the plunge!