with no return filter those shavings always wind up in the tank.
systems today use the return filter to catch these kind of things but in the older systems they just used the inline filter to keep it out of the pump just in case there were trash in the tank.
examine them and determine if they are steel or aluminum shavings first. My best guess would be either an attachment cylinder or like was mentioned... a steering cylinder. But in all honesty it could of come from anything moving in that system.
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