Loader Cylinder Operation

They work fine raising the loader, but when I lower the loader, it seems to put a lot of stress on the tractor/hydraulic pump (the tractor engine actually bogs down a little).

Edited by steve(ill) - 24 Nov 2021 at 2:17pm

Your having trouble DUMPING the oil back to sump at the same time the PUMP is pumping back to sump... Something is TOO SMALL compared to the low volume system.. Hose / COUPLER/ return port in valve.... If the LOW and HI systems are using different COUPLERS, that might be a spot to look ?

Whenever you try and use a one-way cylinder on a tractor with two-way hydraulic valves, you will get exactly what you are experiencing.  I hope you have the hose plugged in to the correct outlet??   Pull back on the remote lever to raise the loader??   If you throw your remote lever all the way forward into "float", the loader should drop freely to the ground with no laboring of the engine. If you move the remote lever slightly forward from the HOLD position, you are in the lowering position and the hydraulic valve is trying to send oil out of the coupler that you aren't plugged into on the back of the tractor. The engine should labor!! because it's trying to pump oil and it cannot go anywhere because you don't have a second hose to plug in !!   The One-Eighty tractor will act exactly the same if you place the lever in the same lowering position.  Get two-way cylinders or get used to how this works with one-ways.

High pressure A-C system only had one hose/one coupler and was oil out to raise and oil back in to lower by gravity. Doesn't work like the two-way systems at all.

I can see when using the high-pressure rams (smaller diameter) how the speed going up and down would be fast....much faster than the larger diameter low pressure rams. So, there is a sweet spot in the activation of the hydraulic spool where oil could be very SLOWLY coming back thru the valve, while not quite applying down pressure at the lowering outlet, hence no laboring of the engine. With the small rams, they would come down faster than the larger rams, so maybe to get the same drop speed, he is stroking the spool just enough farther to now start pressurizing the lowering circuit, causing the engine to labor. It's what is supposed to happen, or the hydraulic pump would explode. And, regardless, the One-Eighty will act the same exact way all things (and I mean everything) being equal. Both tractors have the exact same hydraulic valves !! The One-Eighty has much longer levers, which "feel" a little different than the D-17 IV, but the valves are identical between the two tractors.

I should further explain.  When I put the low pressure larger cylinders on the loader, they already had the hoses connected to them so there are different hoses and coupler end that connects into the hydraulic coupler on the tractor.  I was thinking, that with the larger cylinders and hose/coupler the loader did not creep down when the tractor was turned off and left sitting.  However, with the high pressure cylinders and hose/coupler connected to them on the loader, it will creep down when the tractor is off and left sitting.  Perhaps it is the hose coupler end that is creating the issue?  Interestingly, the loader on my one-eighty does not creep down when the tractor is turned off and sitting.

There are no external leaks.  For the time being, I've decided to leave the old original high pressure cylinders on.  While the lift capacity isn't as great as it would be with the low pressure cylinders, I can pretty much lift 99% of what I'm doing, so go with what works, I guess.