In all honesty, what should be the life expectancy of a loader?all the loaders i have been around were pretty beefy. The loader on my allis is not showing any signs of stress and it old-old. I have had to put rebuild kits in all of the cylinder (I got my goody out of them no complaint) and I have had to put some hydraulic lines on it ( I got the goody out of them no complaint) that loader and bucket are not going to wear out anytime soon. I worry more about busting a spindle on the tractor. For me to imagine a loader to be wore out in 1500 hours is tough.
Try to remember, we're talking about a BUCKET, not a LOADER. A LOADER is the structure, or assembly, that connects to the tractor, has hydraulics, and lifts the implement (in this case, a BUCKET).
Under normal use, with no irregular abuse, I'd expect the LOADER to last the life time of the tractor. Of course, you may need to replace pins and bushings at some point, but overall, the loader frame and assembly should last thousands of hours.
But with a BUCKET, it all depends on the build strength of the bucket (built to a certain required weight and strength) its intended and actual uses, level of abuse, and environmental factors. Like i said above, i bought a new Tomahawk SkidSteer bucket, and it's total garbage, cracks and uneven, within 200 hours. That's clearly a result of either build quality issues... Or... I'm using it beyond it's capabilities. Which shouldn't be the case because it's marketed as a 72" SkidSteer bucket, and most SkidSteers with a 72" bucket have lift ratings around 5000 lbs, and I'm using it on a 6000 lb tractor with a 2500 lb lift rating.
I think your tractor has a BUCKET that is designed and intended for light duty use (built to meet a specific weight and strength target) ... And you've used it heavily for 8 years and 1500 hrs, and simply, it's worn out.