Tractor hydraulics

[Blobber]

Hydraulics is a bit of a black art to me so any pointers please!
The little Leyland has this set up, the lever/spool valve thingy does the up/down for the rear top link but im assuming this little old style connector is under pressure all the time? is it as simple as swapping the connector over for something more modern so I can plug in stuff like a post knocker that has its own spool valve??

 

[Guineafowl]

Not sure of your exact setup, but if that connector in the second pic is a tipper, then it feeds and returns down the same pipe, depending on lever position.

I’d take the whole thing to the hydraulic shop and get them to make you up a new flexi hose with modern connector. The return of your implement will likely need to free-flow into the filler hole. You then tie the lever in ‘constant tip’ position, using the traditional bit of bailer twine.

 

[minimutly]

From my limited farming knowledge I would suggest the "tipper" feed needs to go to a second spool valve - the post knocker up down that reverses the pressure. (Many hours spent trying to deliver stacks of hay bales to the top of trailers, with spool valves, clutch, brake (optional sometimes), and hand throttle, whilst loaders alternately grabbing or diving for cover, during haymaking).

 

[seriesonewelder]

Not sure of your exact setup, but if that connector in the second pic is a tipper, then it feeds and returns down the same pipe, depending on lever position.

I’d take the whole thing to the hydraulic shop and get them to make you up a new flexi hose with modern connector. The return of your implement will likely need to free-flow into the filler hole. You then tie the lever in ‘constant tip’ position, using the traditional bit of bailer twine.

Leyland 154, I used to use and service one. I'd go with what Guineafowl recommends.

 

[sako243]

@Blobber where do the hoses into the spool valve go off to? Trace them out and you should be able to see what's pressure out, pressure in, tank return etc.

 

[Blobber]

@Blobber where do the hoses into the spool valve go off to? Trace them out and you should be able to see what's pressure out, pressure in, tank return etc.

The group of 3 pipes is feed in, return and a feed out to a redundant front loader, the group of 2 is the lift for the 3 point linkage and to the connector which im now assuming is for a tipping trailer as suggested
Not sure how the front loader would have worked as weve never used it, it has a separate 1/4 turn valve by the gearstick so im wondering now if that's a full pressure output that could be used for a post knocker that has its own spool valve?

 

[sako243]

The loader would likely be what they call power beyond I think. If I'm explaining this correctly the tipper spool valve / 3 point essentially dump back to the tank via that valve.

To run the loader if you tapped off the output of that valve you'd have to hold the lever down while operating the loader. Effectively they tap in before the valve and between the pump so you get continuous pressure that you can use. I'd assume you could attach a spool valve onto those.

My post knocker (for a compact tractor) just uses one hose (like a tipper) because most rely on gravity to knock in rather than hydraulics but it's manually adjustable angles etc. If yours is similar you could use the trailer socket.

 

[plewlandsbob]

I am an Agricultural Engineer, although it is probably 25 years, since , I worked on a Leyland. Guineafowl, is pretty much spot on. That coupling , is for the tipper / external service. If you unscrew the pipe , from the back of that fitting, it will be a 1/ 2" bsp thread. All you need to get is a bulkhead fitting, a Dowty / bonded seal and a female coupling and you can use existing bracket.
For operating a spool block you will have to put in a free flow return. Usually done through filler plug on older tractors.

 

[Blobber]

What I dont get is how some stuff needs a return and some doesnt?? as Sako has said the post knockers ive seen only have one connection which goes to the spool valve on the knocker??

 

[Kayos]

What I dont get is how some stuff needs a return and some doesnt?? as Sako has said the post knockers ive seen only have one connection which goes to the spool valve on the knocker??

Does the knocker only hydraulic one way? So only needs one pipe and gravity does the rest?

 

[plewlandsbob]

Post knockers, with one hose , use a single acting ram, that means it uses oil pressure to extend and lift the hammer. Gravity and the weight of the hammer, force the oil, back out of the ram, when control, is put to drop. Any adjustment , to angle of hammer , are by use of a toplink ( a large turnbuckle, to non tractor people).

Larger/ more modern/ more expensive ones, have a spool valve bank, and use hydraulic rams, for making adjustments.
They have two hoses, a feed and a return. The oil flows continuously around the system, until you work a service and oil is sent to move a ram. If you did not have a return, the oil would dead end and blow the tractor relief valve continuously and get the oil very hot very quickly.

On your tractor, the front loader, probably used , two single acting rams to lift it, and gravity to lower. The bucket or fork, would have been a cable operated , trip release.basically a cable would pull a locking pin out , allowing bucket to tip forward to empty. You would lower loader down to push bucket back around and lock in.

The loader and tipping pipe would be operated by the same lever. Tap is to isolate loader, if you want to use rear service, so that loader does not try to operate at same time.

 

[Blobber]

Post knockers, with one hose , use a single acting ram, that means it uses oil pressure to extend and lift the hammer. Gravity and the weight of the hammer, force the oil, back out of the ram, when control, is put to drop. Any adjustment , to angle of hammer , are by use of a toplink ( a large turnbuckle, to non tractor people).

Larger/ more modern/ more expensive ones, have a spool valve bank, and use hydraulic rams, for making adjustments.
They have two hoses, a feed and a return. The oil flows continuously around the system, until you work a service and oil is sent to move a ram. If you did not have a return, the oil would dead end and blow the tractor relief valve continuously and get the oil very hot very quickly.

On your tractor, the front loader, probably used , two single acting rams to lift it, and gravity to lower. The bucket or fork, would have been a cable operated , trip release.basically a cable would pull a locking pin out , allowing bucket to tip forward to empty. You would lower loader down to push bucket back around and lock in.

The loader and tipping pipe would be operated by the same lever. Tap is to isolate loader, if you want to use rear service, so that loader does not try to operate at same time.

That makes sense
So as suggested above can the return just be dumped straight back into the tank?

 

[Erie Fred]

That makes sense
So as suggested above can the return just be dumped straight back into the tank?

Make sure you get the correct spool valve, It sounds like a normal "open center" system
is what you have.

 

[Newlands]

I’ve got the same tractor. I built a log splitter from a Flowfit kit. Changed that trailer tipping Dowty connector for a modern push fit and used that for the hydraulic feed, with the return going straight back to the tank.
The way the hydraulics work, that lift lever has to be in the up position, your 3 point linkage will therefore be fully raised before oil gets pumped to the ram in the log splitter (or whatever your accessory is). I didn’t realise this when I first tested my splitter, and was a bit surprised to find my log splitter going skywards rather than splitting the log - I caught it before it hit the top of the cab!
So, I have to split logs with my splitter disconnected from the 3 point linkage - no big deal but not what I intended. Other tractors of this vintage have a valve to switch to externals, and I suppose I could fit one in the pressure line leading to the lift valve pictured in your first photo.

 

[Blobber]

I’ve got the same tractor. I built a log splitter from a Flowfit kit. Changed that trailer tipping Dowty connector for a modern push fit and used that for the hydraulic feed, with the return going straight back to the tank.
The way the hydraulics work, that lift lever has to be in the up position, your 3 point linkage will therefore be fully raised before oil gets pumped to the ram in the log splitter (or whatever your accessory is). I didn’t realise this when I first tested my splitter, and was a bit surprised to find my log splitter going skywards rather than splitting the log - I caught it before it hit the top of the cab!
So, I have to split logs with my splitter disconnected from the 3 point linkage - no big deal but not what I intended. Other tractors of this vintage have a valve to switch to externals, and I suppose I could fit one in the pressure line leading to the lift valve pictured in your first photo.

I'm wondering now if it's worth bypassing the existing valve and go straight to a quick release from the high pressure line?

 

[addjunkie]

I'm wondering now if it's worth bypassing the existing valve and go straight to a quick release from the high pressure line?

That wouldn't give you any control over what ever you connect it too from the tractor.

 

[Blobber]

That wouldn't give you any control over what ever you connect it too from the tractor.

But if whatever you connect has it's own control valve you won't want control from the tractor? Not sure how to do it just trying to get ideas

 

[addjunkie]

But if whatever you connect has it's own control valve you won't want control from the tractor? Not sure how to do it just trying to get ideas

Id agree, but do you want to get out to tip a trailer for example.