Loader

[CBCGC1715]

I have a question if the loader on my new GC1715. Will it sag when resting for a period of time?

 

[Diggin It]

There was a big thread on this topic not too long ago that had people defending their positions. The general consensus is that it SHOULD not, but there is no guarantee it WILL not.

It's also good practice to make sure you lower it to the ground when shutting the machine off and leaving it unattended.

 

[CBCGC1715]

There was a big thread on this topic not too long ago that had people defending their positions. The general consensus is that it SHOULD not, but there is no guarantee it WILL not.

It's also good practice to make sure you lower it to the ground when shutting the machine off and leaving it unattended.

Thanks for the info. It makes sense to not have the loader suspended, but I just wasn't sure if the cylinders would allow fluids to flow when in the off position.

 

[Wagtail]

With the engine turned off there will be 'bleed down' of your suspended hydraulic implements such as the FEL (Front End Loader), 3PH (3 Point Hitch), backhoe, etc... Most of the time it will be unnoticeable for quite a period of time; a gradual lowering as there is no pressure from the hydraulic pump and the associated system to the cylinders.

This is normal.

If you experience a rapid lowering (with the engine turned off) then you are experiencing a problem.

 

[oosik]

My FEL does not sag. Nor does my 3-point. However - I lower both the grapple & rear blade to the ground. Takes the pressure off the seals and no danger of somebody getting hurt if either should sag or be accidentally lowered while playing on great grandpa's tractor.

 

[LD1]

Thanks for the info. It makes sense to not have the loader suspended, but I just wasn't sure if the cylinders would allow fluids to flow when in the off position.

The cylinders will NOT allow flow when off and valve in neutral.

IF it says, the VALVE is what's allowing fluid flow.

There are no seals in the valve. Just very tight tolerance steel spools in a cast iron bore. Not a guarantee 100% seal. Thus some leakage is possible.

 

[cdaigle430]

Ive been around hydraulic equipment for a long time and with the exception of a few they all sag most of the time.

 

[Thomas]

Depends on what you mean "period of time"
Some loaders have locking device,loader for Kubota L2800 located front of joy stick...and it works just fine.

 

[LD1]

Most of the "locking decives" including the ones on kubotas are just a manual lockout to prevent joystick movement. If the valve is leaking internally, it wont change a thing weather its "locked" or not

 

[thekkfan]

I lower both the grapple & rear blade to the ground. Takes the pressure off the seals and no danger of somebody getting hurt if either should sag or be accidentally lowered while playing on great grandpa's tractor.

What he said. More important than the parking brake, unless you have no implements attached. :laughing:

 

[DMW]

What he said. More important than the parking brake, unless you have no implements attached. :laughing:

Never depend on the parking brake:
https://www.tractorbynet.com/forums/massey-ferguson-owning-operating/175414-gc-parking-brake-popped-out.html#post1998872

 

[lpakiz]

I have a brand new (well, 20 months old) MF 1754 and the loader valve and the cylinders will both allow sag overnight. The way i know the cyliders allow sag is i installed a hydraulic (high pressure) ball valve to be able to lock my loader in a raised (and potentially dangerous) position. Even with the ball valve closed, my loader will sag. I interpret this to mean the cylinders themselves are leaking a small amount of oil from the raise side of the cylinder piston to the lower side of the piston.
For comparison, I used to have a 1954 Case 400 tractor. (about 45 HP, but these horses were a bit bigger than the 54 horses Massey put under my new hood)
The 3-point (Eagle Hitch, to be more accurate) would hold up a darn heavy, 9 foot wide, 4 foot high home made back blade (made for snow) all summer. Never sagged an inch. Did i mention that blade was very heavy?
So my experience has been some cylinders hold, some dont

 

[aczlan]

I have a brand new (well, 20 months) MF 1754 and the loader valve and the cylinders will both allow sag overnight. The way i know the cyliders allow sag is i installed a hydraulic (high pressure) ball valve to be able to lock my loader in a raised (and potentially dangerous) position. Even with the ball valve closed, my loader will sag. I interpret this to mean the cylinders themselves are leaking a small amount of oil from the ”raise side of the cylinder piston to the “lower”side of the piston.
For comparison, I used to have a 1954 Case 400 tractor. (about 45 HP, but these horses were a bit bigger than the 54 horses Massey put under my new hood)
The 3-point (Eagle Hitch, to be more accurate) would hold a darn heavy, 9 foot wide, 4 foot high home made back blade (for snow) up all summer. Never sagged an inch.
So my experience has been some cylinders hold, some dont

If you think about it, it is not possible for your loader cylinders to leak down much at all without a leak in the loader valve.

As the cylinder retracts, the rod displaces hydraulic fluid and enough hydraulic fluid to match the displacement of the rod that goes in has to go somewhere.

If your ball valve on the base end is not leaking (along with the corresponding port on the loader valve) the only way for it to lower would be for it to either:
1. Leak past the base seal and then go out through the rod seal.
2. Leak past the base seal and then leak through the rod side of the hydraulic valve.

Otherwise, it is physically impossible for the loader lift cylinders to retract as hydraulic fluid is essentially incompressible and the fluid displaced by the rod as it retracts has to go somewhere.

Aaron Z

 

[lpakiz]

Aaron,
Yes, i understand that oil is not compressable. But the loader does sag. No doubt! We are in the middle of our maple syrup season here and i left a bundle of slab wood on the forks with the ball valve closed. I highly doubt (but theoetically possible, i suppose) that the new ball valve leaks. The forks are several inches lower this morning than they were last night.
Do you suppose that the bypassed oil (if that is whats occurring) does in fact pressurize the other side of the piston and THEN leaks thru the spool valve, and back to the resevoir?
That oil has to go someplace. A cubic inch of oil is a cubic inch of oil. It cant expand and it cant shrink.

 

[aczlan]

Do you suppose that the bypassed oil (if that is whats occurring) does in fact pressurize the other side of the piston and THEN leaks thru the spool valve, and back to the resevoir?

It has to, there is no other place for it to go unless it is leaking to the outside.

Aaron Z

 

[LD1]

A cubic inch of oil can't expand or shrink....And it cannot compress.

So to "sag" means you are pushing a solid round cylinder rod down into the barrel of the cylinder. The oil Thai it displaces most certainly has to go somewhere. And if there is no oil on the floor.....only place it can go is back trough the loader valve

 

[Diggin It]

There was a big thread on this topic not too long ago that had people defending their positions. .

I remember now ....


https://www.tractorbynet.com/forums...g/405046-front-bucket-dropping-overnight.html


.

 

[cdaigle430]

Its the nature of fluid, temperature, weight everything has an affect on it. Most will leak back to the reservoir and it is the reason why most equipment has a physical lock....why you must use jack stands when lifting a car, backhoe locks when transporting your tractor, even car transmissions have a physical lock.
I think the severity of the sag time wise can dictate if a part is defective....but sagging does not mean there is something wrong and you need to replace parts by definition.