Gallon per minute rating

[Dave31]

I have a MF 1533, and I am adding the Messicks 3rd function kit. However my tractor does not have a power beyond port and I have been instructed by messicks to plum it into the return underneath my tractor. The problem is that the kit I have is only rated for 12 gpm and I have heard that the return on my tractor is running at 12.9 gpm (possibly 14 gpm). What type of issues would there be if I went ahead and plumbed it into the return? Is there some way to maybe run a T valve to lower the gpm going to the 3rd function valve?

 

[ptsg]

Accordingly to TractorData, that tractor has 14GPM total flow, however this is misleading. What it actually has, is two hydraulic pumps, one putting out 9.1 GPM and the other 4.9 GPM, but these flows don't combine together.

The 9.1GPM pump will handle the loader, remotes, 3 pt hitch and 3rd function if installed.

The 4.9GPM pump will handle the mainly the steering, possible the charge pressure for the HST and the PTO clutch pack in some tractors.

The flow that matters for your 3rd function is the 9.1GPM, which is well within the 12GPM rating of the valve.

Also, if you have a loader, you have power beyond port from the loader valve that you can feed the 3rd function with.

 

[Dave31]

So I've looked into it and somehow, this tractor has a loader but no power beyond port. I've seen another thread on this forum about the 1533 not having a power beyond port and just plumbing it into the return valve. Now if the loader is putting out 9.1 gpm and the steering is putting out 4.9 gpm, does that mean that both paths of flow would be combined into the return and that the return would be cycling 14 gpm?

 

[ptsg]

So I've looked into it and somehow, this tractor has a loader but no power beyond port. I've seen another thread on this forum about the 1533 not having a power beyond port and just plumbing it into the return valve. Now if the loader is putting out 9.1 gpm and the steering is putting out 4.9 gpm, does that mean that both paths of flow would be combined into the return and that the return would be cycling 14 gpm?

No, they return via separate hoses and ports back to the transmission.

I'll be reading the other threads about the Power beyond.

 

[bearthebruce]

The info that @ptsg has given is what I have read in the service documents on the MF1533 which we have.

I wanted to put a hydraulic powered cutter out front of ours but learned that we could only get max of 9.1 gal/minute flow - not enough to run the cutter.

I too want to add a third function. I'll let you figure it all out and then ask that you share the details!

I am a lazy old man!

 

[CliffordK]

As far as the return, that should be running at low pressure. I suppose you could overwhelm it if you tried to plumb in something at an extremely high flow. But I wouldn't worry about it too much for a couple of GPM difference. It will be rare that you'll be running all of your devices at at full flow. Steering, bucket, and rear hydraulics, etc. Maintaining pressure isn't the same as high flow. Also, the return should be sized for the pumps on the stock tractor.

I wanted to put a hydraulic powered cutter out front of ours but learned that we could only get max of 9.1 gal/minute flow - not enough to run the cutter.

I have recently considered some of the "high flow" skid steer devices.

You could purchase a PTO driven pump up to the full power of your tractor. For your Massey, that would be somewhere around 25 HP (at the PTO).

Some of the vintage tractors and crawlers also ran a PTO pump directly off of the front of the crankshaft.

If I was adding an auxiliary pump, it would probably have its own hydraulic reservoir.

 

[EdGooding]

I'm not familiar with the term "third function" but, when I bought my MF-1533 new in 2006 I had the dealer install remote hydraulics so that I could operate my hydraulic toplink. Hope this helps some.

 

[Dave31]

No, they return via separate hoses and ports back to the transmission.

I'll be reading the other threads about the Power beyond.

Thanks. What is the worst that would happen though if it were cycling too many gpm for the 3rd function implement? Is there a risk of the valve cracking, blowing up or anything like that? Possible damage to the hydraulic unit?

 

[ptsg]

Thanks. What is the worst that would happen though if it were cycling too many gpm for the 3rd function implement? Is there a risk of the valve cracking, blowing up or anything like that? Possible damage to the hydraulic unit?

It would only be 2 GPM and only at max RPM pretty much, so not much would happen really. Maybe a little bit more heat at high RPM, I would say not even noticeable but then again, it will only be seeing about 9 GPM. The steering circuit is an independent circuit and only shares the fluid, nothing else.

EDIT: Do you happen to have a service manual for the tractor? Where you could see the hydraulic diagram? That would help figuring out where to connect the 3rd function. Using the Tank port of the loader valve is not a solution.

 

[CliffordK]

EDIT: Do you happen to have a service manual for the tractor? Where you could see the hydraulic diagram? That would help figuring out where to connect the 3rd function. Using the Tank port of the loader valve is not a solution.

Right.

Pull fluid out of a hose or manifold as close to the pump as possible (or say a manifold feeding your control levers).

Dump fluid back as close to the tank as possible, or into a main return line or manifold.

The feed line should be high flow, high pressure.
The return line should be high flow, low pressure.

I saw a YouTube video of someone concerned about pressure in an oil cooler on the outflow of a piece of equipment.

That would only be a real issue if there was either an outflow obstruction, or perhaps the device creating pressure pulses.