Has anyone adjusted the Loader Relief valves, or the system PSI ???

[TSO]

Was reading some other (unrelated to LS) posts on TBN the other day, and someone mentioned that we can pretty easily adjust the operating pressure of our hydraulic system, and/or set the relief pressure of the loader hydraulics to gain a bit more lift, etc ...

Has anyone done this, and/or, does anyone know where the adjustment would need to be made to try it? This is just a hypothetical, I'm just curious if it would be worth doing. Someone mentioned that his JD dealer said not to go over 2800 psi because it would cause chattering, but the factory specs were around 2400, so the JD dealer/mechanic seemed to find no problems with a minor adjustment. Allegedly ...

 

[rwork]

TCO, I've been curious about the same thing. I'd like to check the relief pressure on my loader, but not quite sure how to go about it. I've seen some simple gauge setups, but I'd be interested in finding out exactly how to do it on my LS. I prefer to get my info, brand/model specific.

 

[/pine]

I increased the loader valve relief from about 2300 to about 2600...simply by loosening the lock nut and slightly tightening the set bolt...

some valves require a heavier spring or shims or washers to increase spring pressure on the relief valve...

either way you would need to install a pressure gauge to monitor...

If you have any "iffy" hoses (or slow leaking cylinders etc.) I would replace them before increasing the pressure...

 

[Ilikeurtractor]

I'd avoid adjusting the pressue set point higher than factory settings. It's good to check it and make sure it builds to the factory setting, but going above is asking for trouble. I'm sure the engineers who design these are trying to get you the best balance of longevity, safety, and performance they can. If there would be no consequences to going higher, why wouldn't they in the first place? From a marketing standpoint, I'd much rather have a tractor that can lift 1100 lbs vs. one that can only lift 900 lbs. if it were only a matter of the relief valve set point. I'm not saying it can't be done, just there are sound reasons why it isn't. The additional stress on the loader arms can be significant for even a small increase in pressure. It's easy to get higher rated hoses, but what about the control valve blocks and piping? Maybe not an issue when you first turn it up, but what about over a 10 year period of cycling the system at the higher pressures? To prevent fatigue-stress cracking in steel, a general rule of thumb is to not exceed stress levels past 40% of the ultimate strength of the steel. Can you be certain you're not doing that by cranking up the pressure? Not trying to "rain-on-the-parade" here but just pointing out things to consider.

 

[rwork]

I don't believe I'd go above factory spec either, but I'd like to check to make sure it's set at spec. Sometimes my loader will just max out, and other times it will lift the back end up!

 

[TSO]

I increased the loader valve relief from about 2300 to about 2600...simply by loosening the lock nut and slightly tightening the set bolt...

some valves require a heavier spring or shims or washers to increase spring pressure on the relief valve...

either way you would need to install a pressure gauge to monitor...

If you have any "iffy" hoses (or slow leaking cylinders etc.) I would replace them before increasing the pressure...

Was this on an LS tractor?

 

[sdef]

I did this to my Kioti DK45 HST. Conceptually it is the same process on any system I would imagine. Per my shop manual I was to have 2702 PSI at a rear remote at wide open throttle. I had 2600 PSI. The actual adjustment was a quick 10 minute fix from beginning to end.



My adjustment was on the outside, back corner of the FEL control valve assy- opposite the side where the 4 QD hoses are connected, which was very easy to gain access. I just had to loosen the lock nut with something like a 22mm open end wrench and turn the 6.0 or 6.5 MM allen type screw 1/4 turn to move it from 2600 pounds at WOT to 2750 pounds at 2500 RPM- my PTO RPM and the max I will ever have the RPMs to.

I built my assembly with all parts from Discount Hydraulics. It is a pass through type so I can hook it up inline to troubleshoot an operational system later. Or one can just design a deadhead system for a bit less money. I bought all two sets of each of the four QD coupling types I have on mine for connecting inline should that ever be required. The 1/4" hose is to allow the coupling to be connected to any fitting and allow me to be at the throttle, FEL control stick, etc. and still be able to read the gauge. I have another 18" long, 3/8" hose for inline connection adaption, should that be necessary.

You can build a dead head type assembly for $75 - $100 depending upon coupling types up to the $200 + I spent with all of the flexibility I built into mine with extra couplers.

 

[J_J]

Most all hyd system have one or several relief valve, and most can be adjusted.

When new, the reliefs are set at the factory for whatever reason.

Should you need to check the relief pressure or change the pressure, you need a hyd gage installed before the first valve.

Some relief have an adjusting screw, and others have shims to adjust the pressure.

If the machine is still under warranty you can check it, but do not adjust it over the tractor specs.

Here are some hyd test sets one can build for about $30.

 

[sdef]

Most all hyd system have one or several relief valve, and most can be adjusted.

When new, the reliefs are set at the factory for whatever reason.

Should you need to check the relief pressure or change the pressure, you need a hyd gage installed before the first valve.

Some relief have an adjusting screw, and others have shims to adjust the pressure.

If the machine is still under warranty you can check it, but do not adjust it over the tractor specs.

Here are some hyd test sets one can build for about $30.

I like your can of "lube" in the third photo

 

[Guesseral]

For the LS I think you can just disconnect the hydraulic QC hoses for the loader and plug in a gauge then operate the handle (it could be the same on other tractors also) the set pressure should show on the gauge.