Open Center vs Closed Center

[Imaybail]

A friend called me today with a question about his tractor hydraulic system. He has a Massey 383 with a Bush Hog brand FEL. The hydraulics for the loader are run from one of the remotes on the rear of the tractor. The way he describes it, he has to put the remote in "float" position to run the loader. Then if he forgets to take the lever out of float, the hydraulic fluid gets very hot. I think the pump is deadheading and heating up the fluid.
He also has a batwing cutter that he wants to run off the two remotes. He will take the loader off and use both remotes to operate the two functions on the batwing.
Will this work with the hydraulic system on his tractor?

My experience has been with open center hydraulic systems, and I think his system is closed center. Some basic information regarding the working differences would be helpful.

 

[CalG]

A friend called me today with a question about his tractor hydraulic system. He has a Massey 383 with a Bush Hog brand FEL. The hydraulics for the loader are run from one of the remotes on the rear of the tractor. The way he describes it, he has to put the remote in "float" position to run the loader. Then if he forgets to take the lever out of float, the hydraulic fluid gets very hot. I think the pump is deadheading and heating up the fluid.
He also has a batwing cutter that he wants to run off the two remotes. He will take the loader off and use both remotes to operate the two functions on the batwing.
Will this work with the hydraulic system on his tractor?

My experience has been with open center hydraulic systems, and I think his system is closed center. Some basic information regarding the working differences would be helpful.

According to TractorData, the M-F 383 is open center Hydraulics. Not the last word on anything, but ...

Perhaps there is a piping error in the loader valve installation.
Is there a useful return to tank line?

 

[Imaybail]

The way he described the plumbing, the loader valve is supplied by the remote and returns to the remote, but the lever has to be in the float position. But if you leave the lever in float, the fluid gets very hot,
like you are deadheading the pump.

 

[CalG]

The way he described the plumbing, the loader valve is supplied by the remote and returns to the remote, but the lever has to be in the float position. But if you leave the lever in float, the fluid gets very hot,
like you are deadheading the pump.

I don't think the internet can do anything for your friend without a layout of the hydraulic system.
There is a problem, but describing the problem does nothing to move to a solution.
Perhaps there are others more clairvoyant than I.

But EVERY REMOTE VALVE NEEDS A RETURN TO TANK!

 

[Tx Jim]

I'm confused how FEL valve is being supplied with pressure with """tractor scv in float position""" as normally no pressure is on either breakaway coupler while lever is in float position. The limited time I had any experience with MF tractor hyd's I thought the hyd's operated differently from other brand of tractors that I'm familiar with especially the 3 pt in relation to scv's

I suppose it's possible the FEL control valve is set up for closed center while tractor is open center. Simple test is remove male hyd tip from FEL control valve then with FEL control valve spools in neutral if FEL valve is closed center no oil or air should exit open return hose when FEL valve has hyd or air pressure being applied to "in port". In contrast oil or air should exit the same open return hose if valve is open center when pressure oil or air is applied to in port on FEL valve with spools in neutral position.

 

[Imaybail]

It's not the SCV in float, rather it is the remote that supplies the SCV. I believe that remote has a detent position to hold it open.

 

[Harry in Ky]

I think a number of people are confused here. Jim's mention of the SCV IS the tractor remote valve and not the loader valve. Second, I doubt it's actually in float position. If it were, then no oil should flow to or through the loader valve. A 383 could have a number of remote valve options, some spring center, some with float, and some with what they call kickout detent. I suspect the valve in question has detents and possibly no float at all. Just a guess. If it's a hydraulic detent, then under enough pressure the valve will cancel to neutral requiring it be put back into flow position in order to keep the loader in operation. Many operators will tie the lever in this position for convenience not realizing that fluid passing through the detent mechanism creates heat. Are you sure this may not be the case here?

 

[kthompson]

I sure am no hyd expert but think that tractor (MF had several models they did this on) can have one of two different remote hyd valve systems. One was factory install and the other I understood was dealer installed. The dealer installed unit have a valve on top of the transmission with a short lever for each of the rear remotes. Not sure on this but think the factory install rear remotes had levers on the right side in area of the 3 pth. On the dealer install unit you had to have the rear lift lever think it was fully up to supply the oil flow to the remotes. You could not operate the rear remotes and the 3 pth on that system at same time.

Has your friend had this machine and fel a while or is it new to him? If he has had it a while has it always done this? Is it possible he has hoses improperly connected to the remotes, maybe using the one port on each valve? At least get good pictures of the hose connection and routing for those who can help so they can help.

If not mistaken my brother has this model with the dealer installed rear remotes. Was actually helping with rough cut mower issue hooked to it yesterday. But the remotes should handle the bat wind mower fine.

 

[Tx Jim]

It's not the SCV in float, rather it is the remote that supplies the SCV. I believe that remote has a detent position to hold it open.

Rear remote AKA scv could very well have a detent to hold lever in one position to apply pressure to FEL control valve but that's different from float position.

 

[jb1390]

I'm confused how FEL valve is being supplied with pressure with """tractor scv in float position""" as normally no pressure is on either breakaway coupler while lever is in float position. The limited time I had any experience with MF tractor hyd's I thought the hyd's operated differently from other brand of tractors that I'm familiar with especially the 3 pt in relation to scv's

I suppose it's possible the FEL control valve is set up for closed center while tractor is open center. Simple test is remove male hyd tip from FEL control valve then with FEL control valve spools in neutral if FEL valve is closed center no oil or air should exit open return hose when FEL valve has hyd or air pressure being applied to "in port". In contrast oil or air should exit the same open return hose if valve is open center when pressure oil or air is applied to in port on FEL valve with spools in neutral position.

This was my first thought as well.

A quick test I would try - Disconnect loader lines from remote valve. With engine running, move valve like you would to operate loader. Listen for a load on the engine. It should load up as the valve goes into relief. Assuming it does, then repeat that test with the loader reconnected. See if it sounds the same. If so, the pump is deadheading against a closed center hydraulic valve, and the remote valve is going into relief unless a loader function is being used.