Hydraulic oil circuit

[JohnnyBoy]

I’m wondering about using a log splitter on the 3-point linkage of my FMD that will require both a flow and return circuit. I have a ½ inch flow pipe coming from the hydraulic control which I use for tipping the trailer but I’m thinking about getting a log splitter that will need a return circuit.

How can I rig up a return circuit????

[Ian]

Tap a hole in the oil filler cap. That's how ours is setup.

[JohnnyBoy]

Thanks Ian, this was the way we used to fit the return pipes from rock breakers to the old JCB 3C’s, along the top O/S wing and in to the hydraulic oil filler cap via an extension piece.

I was hoping there would be a bung somewhere else on the back end where I could pipe a return line into.

[Brian]

Under the cross shaft, on the right as you sit on the seat, near the lift lever, there is a return bung.

[JohnnyBoy]

Under the cross shaft, on the right as you sit on the seat, near the lift lever, there is a return bung.

Thank Brian, I'll check it out tomorrow

[JohnnyBoy]

Under the cross shaft, on the right as you sit on the seat, near the lift lever, there is a return bung.

Thank Brian, This looks like the bung to which you refer. I'll get a return circuit set up later this week.

[Brian]

That is the one.

[Ian]

That on ours is missing. Wielded over or something.

[JohnnyBoy]

That is the one.

got the pipe, will fit it tommorow and post a photo

[JohnnyBoy]

That is the one.

Got it all rigged up using the flow pipe that the tipping trailer would normally use and return into the port shown in the picture but Log Splitter wouldn’t work.

Found this port to supply pressure rather than allowing a return for the circuit

[Nick]

that bung supplies oil on my major too, is there any other way to return oil than in the filler cap?

[nathanwhittaker]

Does that bung give out alot off pressure

[Nick]

on mine it seems to give out alot of pressure, as soon as you engage the pto which drives the hydraulic pump, oil squirts out of there. It is not controlled by the lever for the rear linkage from memory on mine.....

[Brian]

Ooops! Think that may be a high pressure tapping point straight to the pump! I was certain that was a return to tank. Sorry chaps, I have no diagrams with me until Tuesday next. It may be that the return will have to go through the filler cap after all.

[Nick]

Never mind, shows you are human after all brian!

[Daves rusty bits]

I`m following this post with interest as a friend is making me a log splitter. My main concern is that the oil flow may not be fast enough and I`ll end up with a machine slower than me with an axe! Also will the splitter have to be taken off the 3 point linkage and be free standing during use as the lift arms will need to be fully up before the trailer pipe cuts in? Or does the trailer pipe work before the lift arms lift ?

[JohnnyBoy]

Does that bung give out alot off pressure

Well thinking I might have an in-compatible self-sealing coupling in the circuit I disconnected the pipe from this port and started Jack up… The engine only ran for a few seconds but it left me with a real mess of oil to clear up.

[JohnnyBoy]

It may be that the return will have to go through the filler cap after all.

While I was tipping my load of Gas this morning I was looking at the exposed threads on the vapour line fittings and they look a similar size and thread pitch to my filler cap. So I’ll be taking my filler cap to the fitters and seeing what they can fitting the can sort me out with.

[super6954]

It may be that the return will have to go through the filler cap after all.

While I was tipping my load of Gas this morning I was looking at the exposed threads on the vapour line fittings and they look a similar size and thread pitch to my filler cap. So I’ll be taking my filler cap to the fitters and seeing what they can fitting the can sort me out with.

Hi Those hydraulic fitting threads on the major are all British standard Pipe (B.S.P) so it should be pretty easy to get them. Don't no if gas fittings are the same or do they use something else Though
Regards Robert

[JohnnyBoy]

Hi Those hydraulic fitting threads on the major are all British standard Pipe (B.S.P) so it should be pretty easy to get them. Don't no if gas fittings are the same or do they use something else Though
Regards Robert

if the filler cap thread is a BSP thread, then I'm laughing, it will be so easy to rig a return circuit through the filler

[super6954]

Hi Those hydraulic fitting threads on the major are all British standard Pipe (B.S.P) so it should be pretty easy to get them. Don't no if gas fittings are the same or do they use something else Though
Regards Robert

if the filler cap thread is a BSP thread, then I'm laughing, it will be so easy to rig a return circuit through the filler

Yep they are thats how the returns are on the older majors here in canada when we put a double acting spool on. one line from pressure and the other straight in the fill plug.Hey I'll give you a free new years tip as well . When i've done them I put a big tee in . I run the return in to the side then a cap/ plug on the top end. If you do that you don't have to mess with taking the oil return line off to put oil in the axle only take the cap off the end It's been a while since I did one and can't remember sizes/ what parts I used but you should be able to work it out .
Regards Robert

[JohnnyBoy]

Thanks Robert, that’s exactly how we used to pipe the return circuit up for the old JCB’s. I don’t mind going directly into the filler rather than using a tee piece because it will only be occasionally that I need to top the backend up with oil…

Thanks everyone, I’ll get it sorted and post a picture.

[super6954]

Hi Johnnyboy
No Problem on the T fitting I only do it as most of the tractors over here in Canada leak so much oil in the cold it's a regular thing to top them up, And hyd return hoses that are frozen stiff are not fun to work with. it just makes life a little easyer and guys like that .
If maintenance is easy theres a 75% chance that oil gets checked and put in not left for another day or until it blows up as you've probably seen before .

So just a little side track here. what old JCB's did you work on 3c"s or early CX'S I used to buy/ repair/ sell and run 3C2/3s and my last one i used was a mk3 9sp syncro std front bucket/ forks and extenda hoe.
Real good heavy machines with a lot of go if you know how to drive a digger . i've pulled rock that these new drivers struggle with and use a breaker on the new machines to do the same job . I wish I bought that last one over to Canada with me . It would still dig the hole to bury the new junk guys rave about over here with that stupid centre mount hoe on
Regards Robert

[JohnnyBoy]

So just a little side track here. what old JCB's did you work on 3c"s or early CX'S I used to buy/ repair/ sell and run 3C2/3s and my last one i used was a mk3 9sp syncro std front bucket/ forks and extenda hoe.

Hi Robert, I don’t want to get too far off the thread but briefly I worked for the Sheffield Corporation Waterworks driving a JCB 3 II (JWE246J) up to 1978 when I went to work for TKL Plant hire driving a JCB 3C III with extending Dipper (MHL602P)… Sad when you can remember the registration numbers. Around Easter 1979 my car developed gearbox problems and while it was of the road, Tommy my boss found me a job near home driving a JCB 6D and I more or less stuck with 360 degree machines until 1987 when I got my HGV licence and went truck driving.

[JohnnyBoy]

I`m following this post with interest as a friend is making me a log splitter. My main concern is that the oil flow may not be fast enough and I`ll end up with a machine slower than me with an axe! Also will the splitter have to be taken off the 3 point linkage and be free standing during use as the lift arms will need to be fully up before the trailer pipe cuts in? Or does the trailer pipe work before the lift arms lift ?

Dave, My splitter’s mounted on the 3-point linkage and it does lift right up before the splitter operates. Yet I find this makes the ideal working height. I coupled the flow pipe up and put the return pipe into the filler port and it works a treat but does splash oil out because it’s not a proper fitting assembly. Hopefully I’ll have it coupled up properly in the next 2-days.