Bucket slowly sinks while mowing

[TXCOMT]

Well, after getting Lil Red, my 2400H, back from the local Branson dealership for some warranty work and an oil change, I noticed the bucket gradually lowers as I’m cutting grass on my property. I’ve noticed no leaks on the barn’s concrete floor where it rests, so I’m at a loss…any ideas?

TXCOMT

 

[Aquamoose]

Either the cylinder seals are worn or your spool valves are worn. Both of which the fluids would bypass the seals internally.

 

[TXCOMT]

Either the cylinder seals are worn or your spool valves are worn. Both of which the fluids would bypass the seals internally.

Hmm…it only has 135 hours on it. Think that’s all it takes to wear ‘em out? My tractor has spent most of that time just cutting, not lifting.

TXCOMT

 

[LD1]

Are we talking just the bucket? As in dumping while mowing? Or the whole loader (raise and lower) is drifting down.

If the whole loader.....cylinder seals being bad is terrible advise.

1. cylinder seals being bad will NOT allow a cylinder to compress. Fluid has to be REMOVED from the cylinder. And the only way for that to happen is either a leak externally, or back through the loader valve.
2. The valve does not have seals that are worn causing this. The valve spool is very tight tolerance metal on metal.

Given that the valve doesnt have seals on the spools/work ports...."some" leakage is considered normal. Most valve manufactures give a spec as what is considered normal. So many mL per hour at a give PSI. Some equipment manufactures do the math for you and convert that to however many inches per hour the bucket can drop when empty to be considered acceptable or not.

Run the tractor, get it warm....then park it with the bucket elevated. Measure how high it is. Wait one hour and measure again. Call branson and see if that is okay?

 

[LD1]

Hmm…it only has 135 hours on it. Think that’s all it takes to wear ‘em out? My tractor has spent most of that time just cutting, not lifting.

TXCOMT

NO. IF it is your lift cylinders and not the dump/curl cylinders.....your seals are fine. Suggesting that they arent is bad advice.

 

[5030]

My 2002 M9 Kubota has done that since new. Gradually the loader drops. I pay no mind to it as it's an internal valve seat leak.

My 2004 M9 (other tractor) don't drop at all.

Obviously, some do and some don't and the fix could be expensive (new control valves) so I disregard it.

 

[TXCOMT]

Sorry for the lack of details … the entire loader sinks; the bucket will stay in whatever position I’ve left it.

It functions and follows all joystick input, but I just don’t remember seeing it gradually lower on its one like this before now!

TXCOMT

 

[TXCOMT]

Are we talking just the bucket? As in dumping while mowing? Or the whole loader (raise and lower) is drifting down.

If the whole loader.....cylinder seals being bad is terrible advise.

1. cylinder seals being bad will NOT allow a cylinder to compress. Fluid has to be REMOVED from the cylinder. And the only way for that to happen is either a leak externally, or back through the loader valve.
2. The valve does not have seals that are worn causing this. The valve spool is very tight tolerance metal on metal.

Given that the valve doesnt have seals on the spools/work ports...."some" leakage is considered normal. Most valve manufactures give a spec as what is considered normal. So many mL per hour at a give PSI. Some equipment manufactures do the math for you and convert that to however many inches per hour the bucket can drop when empty to be considered acceptable or not.

Run the tractor, get it warm....then park it with the bucket elevated. Measure how high it is. Wait one hour and measure again. Call branson and see if that is okay?

Good idea…I’ll static measure it later today and go from there!

TXCOMT

 

[oldnslo]

Since this happened after warranty work I would Also double check any linkage between the joystick and valve spools for binding. If the valve is not returned to spring center it will potentially allow the loader to drop faster than normal.

I know new my 2400H the pivot joints were dry and starting to corrode a little penetrating oil followed by grease freed them up.

 

[TXCOMT]

Since this happened after warranty work I would Also double check any linkage between the joystick and valve spools for binding. If the valve is not returned to spring center it will potentially allow the loader to drop faster than normal.

I know new my 2400H the pivot joints were dry and starting to corrode a little penetrating oil followed by grease freed them up.

Awesome…I’m definitely a tractor noob so I appreciate all that info!

BTW, warranty work was on the driveline…had a leak near the front diff.

TXCOMT

 

[Cougsfan]

In every tractor I have owned I have experienced the loader not staying perfectly in the position you leave it. Sometimes it is the lift that drops, sometimes it is the curl that drops. Sometimes it is both. Unless it is a lot over a short period of time, it is nothing unusual. If it doesn't drop while setting an inch per hour, it is probably not worth addressing as in reality it isn't that big of problem. I have had an old tractor that dropped a foot an hour, and I never felt fixing it was a high priority. Other people might though.

 

[sallyb]

I would have dealer check the cylinders, my 2910i does not do that now, I knew when I bought tractor the bucket would drop and that is not what loader should do, I had all cylinders rebuilt at machine shop, doesn’t happen anymore, the bucket will stay where I put it. It is not normal for bucket or loader to drop while running.

 

[TXCOMT]

Good info, sallyb! My tractor didn’t do this before the service so it may need what a previous poster mentioned, some penetrating oil and grease. Can’t imagine a rebuild is required at this point in its life.

TXCOMT

 

[sallyb]

Well machinery will fail, something is wrong and while it’s under warranty, I would say now is time.

 

[LD1]

I would have dealer check the cylinders, my 2910i does not do that now, I knew when I bought tractor the bucket would drop and that is not what loader should do, I had all cylinders rebuilt at machine shop, doesn’t happen anymore, the bucket will stay where I put it. It is not normal for bucket or loader to drop while running.

Lift cylinders won't cause the loader to drop....running or not.

 

[K5lwq]

Lift cylinders won't cause the loader to drop....running or not.

If you have a valve that has a internal leak of say 4cc per minute. And that is within the specs of that valve. If the cylinder seal is bypassing wouldn't you see a increase in the rate of drop as now it could be leaking from two ports? Just curious.