Had a coolant leak from the oil cooler hose in the 30,000 I’ve owned mine. 132,000 now. Can’t see why the fuel system would go unless it was bad fuel or moisture.
If it is clogged but not cracked, it can go through a baking process that cleans it out but the problem might be finding a shop that offers this service.
Had a 366 on mine and at first the dp was rubbing the cab and it was obnoxious but adjusted it and made it better but it was still louder than I’d like. Had a 4 inch exhaust with a muffler
I found the rebuild kits off of ebay for pretty cheap and they worked but there are better kits out there with 360 thrust bearings and wheel upgrades and all. Pretty easy job just remember its a reverse thread.