John Deere 300X Loader won't lift

Gator6x4 · May 5, 2012

The poster advised he was lifting concrete slabs and then bursting the slabs. My take is he was overloading the pump during the lift of the slab and was leaving the pump in an overloaded condition while bursting the slab and the pump was damaged. Pumps do not like being overloaded with the by-pass valve complaining for several minutes without relief. Sooner or later the pump will stop responding.

Villengineer · May 5, 2012

Once he let off the handle the pump is isolated from the loader. The pressure in the cylinders is held by the valve, not "sitting" on the pump. He may have damaged a piston seal, QD, or control valve due to a pressure spike, but not the pump. If the pump went out it would most likely be a failure due to a different issue such as contamination or a failed main system relief. Another possibility would be if the tractor has a ton of hours on it that something is just plain worn out.

jimmypat6 · May 5, 2012

Hey everyone,

The tractor has 3800 hours on it. I have not gotten a chance to switch the QD's around yet but I did unseat them and reseat them. I have not had the problem since then. Before the curl was working fine but it just didn't want to lift. I worked with it for about four hours yesterday and did not have a problem. I hope this fixed my problem. If there are anymore suggestions please let me know because I will be willing to check it to make sure I didn't break something, I will be switching the QD's just to double check everying is right though.

greg_g · May 5, 2012

Good job. But the fact that you had an obstruction now means it's time to change the fluid and filters. 'Cuz whatever caused the blockage - is still floating around inside. Especially considering 3800 hours, it's hard tellin' how long ago the last hydraulic service may have been.

//greg//