Jerky Loader on L48 ?

[dave7310]

When I have a load of dirt etc in the bucket the loader is very jerky when raised and I can hear a 'swishing' noise in the loader control valve at the same time. With no weight in the bucket it goes up smooth.
Fluid level is fine, no signs of any leaks.
Any ideas ?

 

[Ob1kubota]

dave welcome aboard and it sounds like contamination on the lift side of the spool in the Front Loader valve body. The weight of a fully loaded bucket will be enough resistance to create hydraulic shutter if say a small chip (left over from initial machining process) is lodging between the bore of the valve body and spool and causing the fluid to as you say 'swish' to relief back to case. I don't have a WSM for your 48 but if its a Husco Valve body, I'd start where the noise is coming from. If your not sure which spool trace back from the barrel end of closest lift cylinder to the loader valve body. If your not interested in doing this get local help. Check the tag on the valve for the manufacturer and go to them for a seal kit if you decide to do-it-yourself. Remember Dave this is just my opinion and very basic hydraulics from your description, this may be only the symptom of the problem, but I always go after noise in cartridge valves and the like when looking for contamination.