420 Loader - not level - leaking cylinders?

[swampbuggy77]

I have a 420 cylinder that is always out of level by about 3/4". For a while I just thought the loader was bent. I know my bucket cylinders need to be rebuilt, as they move at very different rates without a bucket attached, and one is leaking pretty good.

My question, could leaking lift cylinders cause a loader to be out of level? If one were leaking internally, causing the other side to push up harder, hence always being out of level?

Any recommendations on how to test? I was thinking of swapping cylinders to the opposite sides to see if I can repeat. Any other ideas?

 

[jeff9366]

Check all four tire pressures first.

5 psi pressure difference between tires on either side can easily cause 3/4" out of level.

 

[jthibodeau89]

Is the bucket twisted, or just out of level?

 

[TractorGuy]

The uneven travel with the bucket off is sheared or worn pins and holes on the timing rod.

As already suggested park the tractor on level ground with the tire pressure set even to measure for a bent frame.

 

[swampbuggy77]

Is the bucket twisted, or just out of level?

The bucket and loader are both out of level. I'm measuring from different points on the loader arms at the pins and cross bars.

What got me thinking was after I removed the bucket (no load), I noticed my bucket lift cylinders operate at different speeds (I know at least one needs to be rebuilt). If the lift cylinders are doing the same, is one pushing harder than the other due to an internal leak that could cause the out of level situation?

 

[swampbuggy77]

The uneven travel with the bucket off is sheared or worn pins and holes on the timing rod.

As already suggested park the tractor on level ground with the tire pressure set even to measure for a bent frame.

What is the timing rod?

 

[Egon]

Will the bucket sit flat on a cement pad with no pressure on the cylinders.

 

[swampbuggy77]

Will the bucket sit flat on a cement pad with no pressure on the cylinders.

Yes it will sit flat

 

[oldnslo]

Swampbuggy
To answer your question yes if one of the lift cylinders is leaking bad enough the cylinders will extend at different speeds and speed difference should get worse with a load in the bucket.

 

[rangerfredbob]

In most loaders both cylinders (both pairs really) are in parallel meaning they get the same amount of fluid on both sides, IE they equalize, any amount of offset from side to side is either back tires being different pressures or the loader frame or bucket is bent from being overloaded more on one side than the other at one point or it was built out of square.

 

[D2Cat]

How long has the problem existed? How old is the tractor, or how long has the loader been on the tractor? It could be some of the bolting hardware is loose or mis-adjusted to begin with. If so, might have the tractor and loader on flat level slab and loosen mounting bolts and then re-tighten them.

 

[TractorGuy]

What is the timing rod?

This illustration just calls it a pin but for some of the other model loader parts they refer to it as a timing rod which is what it actually does. It passes through the bucket holders to time them together. The pins and holes they pass through will wear and often the pins get broken and fall out.

Even with everything equal cylinders will move independently depending on which one gets the fluid first and which has the least resistance. If you connect a dual lid grapple to a loader the lids will never move in unison and both will stop when they get to their compressed point.

When I rebuilt my loader I welded some 1" stop collars to the outside of the holders to center them on the rod better. I bought a piece of 1" cold roll and drilled it to make my own timing rod. JD wants over $200 for the rod. I think I paid $25 for a 4' piece of cold roll. I needed to make my rod longer anyways to pass through the added stop collars. I also drilled the locating pin holes out to 5/16" and put grade 8 bolts in them.

 

[swampbuggy77]

The other odd item is when I extend my loader to the highest position, the right cylinder maxes out before the left. When the right cylinder extends to it's max at 19 1/16", the left is 1/8" behind at 18 15/16". If I continue to drive the loader to it's maximum position, both cylinders achieve the full 19 1/16" position.

The same thing happens in reverse when I lower. The left cylinder drops more at first.

I just did a leak-down test, and saw a drop of 4.6" per hour. I think I'll start with a rebuild of all 4 cylinders and go from there.

 

[swampbuggy77]

This illustration just calls it a pin but for some of the other model loader parts they refer to it as a timing rod which is what it actually does. It passes through the bucket holders to time them together. The pins and holes they pass through will wear and often the pins get broken and fall out.

Even with everything equal cylinders will move independently depending on which one gets the fluid first and which has the least resistance. If you connect a dual lid grapple to a loader the lids will never move in unison and both will stop when they get to their compressed point.

When I rebuilt my loader I welded some 1" stop collars to the outside of the holders to center them on the rod better. I bought a piece of 1" cold roll and drilled it to make my own timing rod. JD wants over $200 for the rod. I think I paid $25 for a 4' piece of cold roll. I needed to make my rod longer anyways to pass through the added stop collars. I also drilled the locating pin holes out to 5/16" and put grade 8 bolts in them.

View attachment 680930

I see now, that makes sense. My pins are still there, I'm guessing the holes have worn out significantly, but I understand now. Thank you!

 

[TractorGuy]

For the loader to lift uneven you would have to have very worn pins and bushings or a bent boom timing tube.

In other words there are no faults related to cylinders that would cause it to lift uneven. As long as the mechanical connections are solid it can only lift evenly.

Now if one of the cylinders had a piston freeze up it is possible the other could produce enough force to tweak the frame but I think that scenario is very unlikely. Even then it would bend the tube that connects the two loader booms together so it should be pretty obvious.

It IS possible to bend the booms and or the connection between them by putting force on it unevenly. If you have used it to lift something heavy that wasn't balanced or pushed on something wrong you CAN twist the frame.

 

[jthibodeau89]

Disregard.

 

[Egon]

Yes it will sit flat

If it will sit flat the problem will probably be with the cylinders. Check how much extension they have and if it is
even. Do this under no pressure and with pressure.