replacing 5 valve bank with a three valve and a 2 valve bank connected

Tx Jim · Aug 20, 2015

According to hyd spec's I located the stand-by pressure is listed at 2000 psi. Ag & forestry use same frt hyd pump( AR56160) as hyd pump for 440C also fits some ag model tractors. I think as long as stand-by pressure is within spec's you'll be fine. I just looked at factory valves and some of the individual sections do have relief valves.

BUT I'll reiterate that my industrial equipment knowledge is limited but not my closed-center knowledge.

quietrangr · Oct 1, 2015

OK< I'm back. It took me longer than I thought to finish the logging job I was on, but I have the machine home now and am installing the different valves. They are a three valve and a two valve bank I'm connecting together in a close center system to replace a five valve sectional bank. They are Cross valves, so I installed the PB plug and replaced the relief valve with a no relief plug (from a kit made for that purpose). I'm installing a relief valve in the pressure line and I want to permanently install a pressure gauge to set and monitor the relief pressure so I don't blow anything up. Where would I install the gauge? Also, I've never adjusted a relief valve before, so how do I do that? Thanks.

J_J · Oct 1, 2015

If you have a closed center hyd system, all valves are in parallel.

No PB is used, and a closed center plug goes in the PB port.

quietrangr · Oct 1, 2015

Thanks, JJ. I guess my other post wasn't clear. I put in the PB plug (maybe I should call that a closed center plug), and a no relief plug in the Cross valves in place of the relief valve, as per instructions from Cross. Both valves are hooked up separately, separate inlets and separate outlets on both valves. But with that no relief plug replacing the relief valves in the two monoblock valves, I needed a relief, so I'm putting one in the pressure line before the first monoblock valve bank. That relief valve will relieve all the valves in the two monoblocks I think you told me before. That seems pretty clear that I put pressure line in and out where it says pressure (arrows going both directions, so flow can directions doesn't seem to matter); the other port on the relief valve I assume goes to return line. But where do I put the gauge so I can test and monitor the relief setting? I would want to just leave the gauge in to keep an eye on things. Also, I've never adjusted a relief valve before, so how do I do that? Thanks.

Tx Jim · Oct 1, 2015

I'm not J_J but you can install pressure gauge in pressure line that exits hyd pump or any hyd function should exhibit stand-by pressure.

quietrangr · Oct 1, 2015

Thanks, TxJim. I'd like to have the gauge so it will show me if the relief valve is working properly, mounted in the cab. And wouldn't I have to have a gauge hooked up to adjust the relief valve? Also, I've never adjusted a relief valve, so if you could point me in the right direction for that. I was surprised there were no instructions in the box.

J_J · Oct 2, 2015

The relief valve will come set to a certain pressure.

Once installed, and gage installed, turn the screw until tractor specs is set.

You can install the pressure gauge in a tee, anywhere in the pressure line.

quietrangr · Oct 2, 2015

Thanks, JJ. I hope to get that together today, and will let you know how it works.

quietrangr · Oct 9, 2015

Hoo, boy. Have you guys noticed that there just aren't enough "errors" in the phrase "trial and error?" The plumbing stuff you guys told me was right on, but the logistics of mounting and compactly plumbing two monoblocks and an inline relief valve where there used to be just a single valve bank were daunting.
Anyway, we finally got it together and seems to be working fine. I've never watched a gauge and and operated hydraulics at the same time before, so is it normal for the pressure to drop from around 1200 to 500 when a valve is fully opened? (This was at engine idle speed, so low flow might cause that.) Machine isn't driveable yet because we had the rear differential out to do some welding, so I haven't really worked the hydraulic system.

J_J · Oct 9, 2015

Pressure is based on the load on the cyl or hyd motor.

Light load will show low pressure and heavy load will show high pressure.

If you can't lift a load, the valve relief is relieving and the load is to much.

Some times you can tilt the bucket back and change the center of gravity and then you can lift more.

The rated load is rated over the lift pins.