Does your 3-point take a hydraulic beating

[sneaky_pete]

</font><font color="blue" class="small">( I have adjustable chain drop limiters on my tractor. Works great, supports my 3/4 ton counter weight well and I can set how low I want the front of my cutter to drop and not worry about it.
The chains hook to the top pin ends on the tractor rear and on the lift arms.
)</font>

Me too. The poor man's position control, but it's simple and easy to use.

Pete

 

[SPIKER]

hi guys thought I toss in my 2 cents:

My JINMA has the same LOCK / LOWER SPEED CONTROL KNOB. anyhow the thing is each HYDRAULIC circuit may be different so making universal quotes won't work. the 3pt pressure relief valve is only in the circuit WHEN YOU ARE LIFTING, and is locked out by the valve I believe, same with a FEL valve, the relief valve is set more or less upstream of the hydraulic control valve for most applications, and usually will only save the pump not the hoses etc down stream of the valves.) I went digging for more info a while back about this, some valves come with LOCK/CHECKS on the valves so that when the valve is set the load can not move. these are more$ so not used very often, way manufactures get around adding the load locks is to make the spool valve the load lock, so that it basically lOCKS the load when the spool is centered.

on 3pt valves, you're relief is on mine again) is upstream / inlet side of the 3pt valve, this will let pressure build in side the tractor lines to it;s relief setting and if it has not yet been reached when pushing the spool valve over to one side the fluid goes through the spool valve once you try to lift too much weight, the relief then opens, and fluid is going through the relief and still to the spool (if it is still being pushed over.) once the spool returns to center then the fluid stops going through the relief and goes through the OPEN CENTER valve.

if you have a CLOSED CENTER SYSTEM (hyd pump is a variable vain pump which always has X000 PSI on it and only adjust the amount of FLOW OUT of the pump then you do not have the open center part of the valve) , but pressure is always on the spool, in these cases then relief valves (if equipped) are more than likely down stream of the spool so that each spool can be adjusted to different max PSI settings.

this means that if you have top & tilt on a closed center system you can have different relief valve settings for each spool... these usually have a center spool mounted spring relief valve, which can be adjustable or non-adjustable or uses shimms... the system can also have a single relief valve for multiple spools but then that goes back to the usually upstream side of the spool...

every valve manufacture is a bit different as they have to be to avoid patent liabilities etc. many ways for many systems :

anyhow hope this muddies up the waters some more /forums/images/graemlins/blush.gif

 

[BillyP]

I've really never thought about it. I just raise the implement and transport on. I've never had any problem with the 3pt hydraulics not holding the implement up during transport.

Seems the leak down on the 3pt system is non existent?

 

[JerryG]

I have never said that you couldn't lock it with the knob, but it is dangerous to the system during transport. The only compact tractor that I can see as maybe being different might be the Grand L's with their external cylinders.

 

[TWINKLE_TOES]

"check chains'

 

[ZJ_HR]

If mentioned tractors have position control, any dropping of lower links, caused by internal hyd leaking will be corrected automatically. When internal leak is strong (worn out o ring on lifting cylinder) 3pt lift jumps often.
Just a stupid question; why you need to lock hyd valve for transport???

 

[MMM]

Not sure if it's available for CUT's, but my Case has a "cushion valve " for 3pt shock loads. My HD cutter also has a set of chains, yoke and it's own notched top link that allow the load to be carried by top link instead of the lift arms while mowing. The cutter is set up with tail wheel and front chain/yoke, then lift arms are lowered completely. The only stress is on sway limiters.

 

[KiotiJohn]

I'm going to have to read this again tomorrow after I've had many hours of sleep!!! I read it over and over until I was more cross-eyed than I was when I got home and it takes some following /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif G'night! John

 

[OkieG]

<font color="blue">... that allow the load to be carried by top link instead of the lift arms </font>

I wish I could visualize that. The top link in my conventional system maintains front-to-back alignment of an implement. It can only be in tension or compression, ie have stretch and squish forces placed on it, and that's about it. It carries a load in the sense that it limits how far an implement can pivot around the lift arm pins. Can you post a picture to show how the toplink carries the load? Thanks.

OkieG

 

[RoyJackson]

"Just a stupid question; why you need to lock hyd valve for transport???"

Not a stupid question...

I can see locking the hydraulics to prevent an accidental lowering of the implement during transport since you cannot lock the rockshaft lever (at least not on my 790).
Also, although the manuals (and common sense) tell you to lower any implements when the tractor is shut down, there may be occasions the implement must be left in the raised position (can't think of any reason though), again to prevent an accidental or inadvertent lowering.
Just remember that even with that hyraulic lock, you don't want to get under that implement!!

However, the lock in conjunction with an adequate number of jackstands may be a reasonable way to work under the implement...not sure I'd do it that way, but I don't make my living on tractors.