JD 300X loader problem.. 3320 tractor

[sgtstew]

I have noticed that recently, my 300X loader w/either pallet forks or buck, will "droop", in other words, either will roatate to a dump configuration. It's a slow creep, even when engine is running, and lift control is centered. The frame lift is ok, just the front end. Was disking last week, with pallet forks mounted. About every 10 minutes, I'd better roll them back or they would fall enough to catch the ground. Both bucket cylinders seem involved, in that at any given time, both cylinder rods will measure the same. So it doesnt seem to be one cylinder having a problem. What's taken place to cause this?

 

[J_J]

Piston seals in the cyl are probably shot. Probably not a spool problem. Does the relief activate when cyl are fully extended?

Even if one cyl is good, the pressure from the bad cyl could leak to the other side of the piston.

 

[kennyd]

JD has a published spec on leak down rates-as well as other OEM's also. Some leakdown is to be expected. Yours does not sound to bad just yet, but you may want to get some seal kits to have in stock for the future.

 

[sgtstew]

Thanks for replies. Question now.... where's the best place to find illustrated R/R ( "remove and replace") information. I'm familiar with hyd. cyls., but I want to make sure it's done as JD has in mind.

 

[kennyd]

Here is a good thread to read: http://www.tractorbynet.com/forums/hydraulics/122281-jd-hydraulic-cylinder-rebuild-help.html

 

[JB4310]

Mine will leak down when not running, but not a noticeable amount when engine is on. I use forks and a home made man lift basket to do some pruning or painting etc. If I kill the engine with a guy working from the platform, I would have to restart every 10 minutes or so to level. If I leave the engine running usually don't have to level it in the time we might be working in one spot.

Sounds like OP's is leaking a little to fast?

JB,

 

[Red Horse]

How many hours do you have???

 

[kennyd]

Mine will leak down when not running, but not a noticeable amount when engine is on. I use forks and a home made man lift basket to do some pruning or painting etc. If I kill the engine with a guy working from the platform, I would have to restart every 10 minutes or so to level. If I leave the engine running usually don't have to level it in the time we might be working in one spot.

Sounds like OP's is leaking a little to fast?

JB,

The engine ON or OFF is irrelevant if the valve is in neutral. If the cylinder are leaking (internal bypassing I should say) then the engine running (pump pumping) has no effect if the valve is not activated.

 

[JB4310]

The engine ON or OFF is irrelevant if the valve is in neutral. If the cylinder are leaking (internal bypassing I should say) then the engine running (pump pumping) has no effect if the valve is not activated.

I somewhat understand your logic Kenny, but I am quite certain about my observations. Are you saying that I should not be seeing what I am ? Or that there are different types of leak down?

JB.

 

[sgtstew]

To "Red Horse"~~~~

My 3320 has 470 hours, probably more than half w/o front loader being used.

 

[kennyd]

I somewhat understand your logic Kenny, but I am quite certain about my observations. Are you saying that I should not be seeing what I am ? Or that there are different types of leak down?

JB.

I am not sure I can explain it better...

If the valve is in neutral, then the pump can't keep the loader from drifting down. It can't just pump a little fluid to the loader to keep it at the same height.

I cannot explain the symptoms you see:confused2:

 

[JB4310]

I am not sure I can explain it better...

If the valve is in neutral, then the pump can't keep the loader from drifting down. It can't just pump a little fluid to the loader to keep it at the same height.

I cannot explain the symptoms you see:confused2:

I know enough not to doubt you, so can there be some leak at the valve, that would prevent leak down when pump was running?

Otherwise I have to question my own observations, but I seem to remember others with similar symptoms.

JB.

 

[Red Horse]

To "Red Horse"~~~~

My 3320 has 470 hours, probably more than half w/o front loader being used.

Ouch! Not good-my 3320 300CX has 700 hrs- and a lot of those hours are loader time- no leaks-uneducated guess-you have packing that was defective.

 

[J_J]

Some valves leak more than others. If the cyl are good, then it is a worn spool.

It doesn't matter if the engine is on or off, with a leaking cyl or valve. More of a load, faster leak.

You could install a needle valve in the curl hose, and tilt the bucket up and close the needle valve. If it tilts down, the cyl is leaking internally. Do the same with the lift hose. Install a needle valve in the lift circuit, and raise the lift arms, and close the needle valve. If the lift arms descend, then the lift cyl need some work.