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Three Point is Down & Won't Go Up At All.
The first thing to check if you have a loader on the tractor is if the loader is still working. This will rule out a pump problem. If the loader is working you can move on to the next paragraph. If the loader is NOT working then there is something wrong with the pump (normally caused by unhooking the hoses while the tractor is running which dead-heads the pump) or a problem with the oil supply (out of oil, dirty filter or screen?). You may need to remove the pump & inspect it for damage if the oil is full & the filters are clean. If you don't have a loader or the loader is working and you have a clean filter & plenty of oil- the next place to check is the linkage going to the valve. Be sure that a rod or pin has not fallen out and that the lever actually moves all the way to the valve. If all of this is ok then you might need to do some more in depth troubleshooting. You could have a bad three point control valve. Three Point Won't Stay Up- Leaks Down. Lift the three point all the way up and close the lock valve (usually located between your knees lust under the seat- see fig A). Shut off the tractor. If the three point still seeps down then you probably have a bad lift piston oring because, by closing the lock out valve, you have eliminated the valve & everything else in the system. If the three point stays up then you likely have a problem with the three point control valve.