Air in backhoe?

[Harry in Ky]

Almost every hydraulic control is in series, from pump to power port (P) on first control valve, out of power beyond (PB) and in to "P" on next control valve and out at PB port into next "P" port and out "PB" to next "P" port and so on... Does not matter if you have 1 or 2 control valves or 10.... Its almost always a series arrangement in a open center system.... And if connected correctly system should be self purging of air after a few valve/ram cycles....

Exactly, but he's not there yet, and on his own he's not likely to get there soon.

 

[Joesark]

Harry, you are absolutely right; I run mainly on enthusiasm and ignorance. I really appreciate all the coaching. Can't send pics now because I'm at work, but I'll get some this evening. It makes sense now that the left side would be the pressure side. In theory, would I be able to hook the right hose to the inlet of the hoe and then hook up the return from the hoe to the reservoir?

 

[Harry in Ky]

Well, sort of. The power beyond will usually be in one of the ports on the right side of the valve. There are often two or three ports there, only one will accept the sleeve. From there to the backhoe valve, and back to the tractor. Exactly WHERE on the tractor depends on whether or not anything is needed downstream from the hoe. If your hoe is three point mounted, and you need to lift it for mobility, then the hoe valve stack should also be plumbed with power beyond. If the three point is not to be used, then the hoe return can go straight to sump.

You might read through this, it will give you some idea of why all this is necessary. It's all second nature to me, since I deal with it on a regular basis, but often people can be confused with it all.

Power Beyond Option Parts | Cross Mfg.

The power beyond sleeve prevents subjecting the exhaust or return passages and spool seals of the control valve to back pressure.

crossmfg.com

 

[Joesark]

Well, it's starting to make sense! I hooked it all up the "sort of" way and ran it at an idle long enough to make sure all of the functions work properly. I have it unhooked now so I won't be tempted to actually dig with it. Is there any special power beyond valve I need, or is it just whatever fits on the loader valve? I have a picture of the downstream side of the valve; which port is most likely to be the one I use?
Thanks!

 

[Harry in Ky]

https://www.northerntool.com/products/chief-power-beyond-plug-model-220915-4875402?cm_mmc=Google-pla&utm_source=Google_PLA&utm_medium=Hydraulics%20%3E%20Hydraulic%20Accessories&utm_campaign=Chief&utm_content=4875402&ogmap=SHP%7cPLA%7cGOOG%7cSTND%7cc%7cSITEWIDE%7cOOT%7c%7c%7c%7c168638876%7c8715914036&gclid=CjwKCAjw9pGjBhB-EiwAa5jl3OdaDFancI-KYdmtpwpzVhxbsK4aXyyFSfE2lZCMlb3WaHaq5EC_8xoCiB4QAvD_BwE&gclsrc=aw.ds

Power Beyond Sleeve Chief Valve 220842 | Valve Parts & Accessories | Hydraulic Valves | Hydraulics | www.surpluscenter.com

Power Beyond Sleeve Chief Valve 220842, Valve Parts & Accessories, POWER BEYOND CONVERSION SLEEVE Brand new, power beyond sleeve for use with CHIEF

www.surpluscenter.com

It looks like you have a P40 valve. Is that what's on the I.D. tag? I've used a number of them. If it's an older valve it will have #10 ORB pressure and return ports. If so it will take the 220 915 sleeve. Newer valves have moved over to BSPP ports now and will take the 220 842 sleeve. It will go int the port marked N. From there a line to the backhoe valve.

That's your starting point

 

[Joesark]

I don't see anything like p40. The number on the tag starts with a k. Not finding any other markings.

 

[WranglerX]

I don't see anything like p40. The number on the tag starts with a k. Not finding any other markings.

What are the rest of the numbers.....Enquiring minds want to know....

 

[dirttoys]

Air in the lines and cylinders will eventually take care of itself. Revisit your plumbing/connections, explain (maybe even post some photos?) how and where you connected to the tractor hydraulics. Maybe your "nothing works" problem can be sorted out.

Just a guess, but I suspect you probably put a tee in a pressure line? That NEVER works.

that is a helluva guess

 

[rScotty]

that is a helluva guess (A Tee in the Pressure Line)

Putting a Tee into the pressure line is a pretty basic mistake. I think we've all done it. Doesn't work.
What happens is that the hydrualic fluid just takes the path of least resistance - which in this case is whichever return line looks most favorable. The fluid returns back to the sump, and never gets around to doing any work.

There is a trick for making Tee connection in a pressure line - and I'm sure that Harry knows this one too. It was commonly done on old Massey Fergusons from the 40s and 50s when people wanted to run a loader and still have 3pt capability.

The trick is that instead of a Tee, you use a manual hydraulic selector valve. The manual selector valve has a hand lever on it that will only let you send pressure to one system at a time.

Here's how it works on a tractor: Most people mount the selector valve on the dash for convenience. You can turn the lever on the selector valve one way to pressurize the 3pt system, raise us the implement, close off the 3pt hold-in-place valve (usually between your feet) and now the 3pt implement is held up & out of the way.
So you reach forward and switch the selector valve over to pressurize the loader and you can use the front end loader for as long as you like....or until you need to shift back to the 3pt. ....and repeat.....

This constant switching can be quite a circus given an old Massy with a pathetic 3 gal/minute hydraullic flow and leaky hydraulics at both ends. But it works. And lots of old farm tractors were rigged that way. It's cheap and easy and any front end loader is a wonderful thing.

I mention it not because it is the best way to do it, but because so many were done that way.
The path that Harry has you on to use the power beyond port is much, much better.

Oh, and DO NOT use plumbing fittings. Use hydraulic fittings. Plumbing fittings will break and spray.

rScotty

 

[Harry in Ky]

I don't see anything like p40. The number on the tag starts with a k. Not finding any other markings.

Well, my eyesight "ain't what it used to be" no argument there, but name on the tag looks like it says Chief. If you pull the plug from the port marked N and look inside I'm betting you find the counter bore machined in to it. If the plug is an ORB #10 thread, I would order the 220 915 sleeve and try it. If I'm wrong you're only out the postage to return it.