Grumpy

I have a Nortrac NT254, a Jinma 284. I was moving a truck load of dirt from one place to another about 150 yards away. I had it in 4WD in order to scoop up the stuff without tearing up my driveway, and I left it there while traveling in 1st gear high range from point A to point B, over and over again on dry hard ground. After probably a dozen trips or so I heard a crunch in my front end and was suddenly an NT252! I guess I overdid it a bit!! The shaft and the ball couplers were unharmed. I dropped the front axle, removed the top cover from the differential, and found that I sheared a few teeth off of 1 or both of the little spider gears in the front differential. Look at the recent upload to the Photo Gallery titled 'Busted!' Look closely at the gear near the bottom of it. I was able to get all the parts I needed online and do the repairs myself.

Smokey,

   You are feeding the diverter valve from the tank return line of your FEL valves. Since you are utilizing the power beyond port on your FEL valves, all excess fluid goes there instead of to tank. You won't get anything to the tank return port on the FEL valves unless you are actually moving the FEL. That is why you don't have any fluid for your power steering. You basically bypassed the diverter valve and PS by going straight from FEL Power Beyond to 3PH.

   You should run your FEL valve tank return line to the steel return line on the left side of the tractor, or just use the original FEL return to tank line. Your FEL Power Beyond port should go to the input port #1 of the diverter valve. Your mystery hose, diverter valve Port #4, should feed the 3PH.

   Or look at it this way : Put everything back the way it was originally. Then pretend you are removing the FEL by taking the quick coupler hoses that went from diverter to FEL valves, and from FEL valve to 3PH, and couple them together. You now have fully operational PS and 3PH, but no FEL. Now interrupt the line from pump to diverter valve and insert your FEL valves there by running pump to FEL valve input and FEL PBY port to diverter valve.

Other experts correct me if I am wrong, but we have to be carefull what we plug! These are 'open center' hydraulic systems. All fluid flows through things, not past them. Even when a valve is not being used to move something, the fluid coming into the valve or set of valves has to have an open path through the valve(s) to something else and eventually the tank. Fluid flows through the FEL valves, out of the power beyond port even when the FEL is not moving, down to the 3PH, through the 3PH hydraulics that are built into the hydraulic sump casing, and then out of the 3PH hydraulics into the sump. If you remove the FEL then, yes you are correct you need to take the hose that used to go from diverter to FEL and connect it to the hose that used to go from FEL power beyond to 3PH. Failure to do so would create a dead end for fluid on that side of the diverter, a 'dead head' situation. I don't know enough about diverters to know if a dead end on one side of it would 'dead head' the pump and blow it up or not but I wouldn't want to try it! I tell you what I did though when I started playing with my hydraulics, to protect myself from any possible situation the first thing I did was to install a stand-alone pressure relief valve as the very first thing on the output of my pump. I am bulletproof! No matter what I do, except for maybe completely plugging the return line to the tank, I cannot dead head my pump.

    Anyway, getting back to the FEL valve plumbing, I think you also need to leave that as it is as long as you are using the Cross valve set. You have to have the power beyond port feed the 3PH. When FEL valves are not activated, all fluid to the 3PH still has to go through the valves, through the PB port, and to the 3PH. You also need the return to tank line from the FEL valves. When you activate a FEL valve, all fluid that used to go to the 3PH gets routed to a FEL cylinder. The cylinder moves and the fluid returning from the other end of the cylinder doesn't go to the power beyond port, it goes to the return to tank instead, I think. That being said however, I have evidence to the contrary. I bought a new set of FEL valves with PB port and put them right in place of the Cross valves. Everything worked but the FEL was still slow. Then I moved them upstream of the diverter valve, removed the power beyond port insert and replaced it with a plug made specially for that valve set, and ALL hydraulic fluid for my tractor now runs into the new FEL valves, out of the return to tank port, and then to the diverter valve. I don't know if those 2 configurations are basically an industry standard or not. If so then you could probably do teh same with the Cross valves. Bob Rooks really knows his stuff. He and probably some others here could either confirm or dispute that idea.   

Smokey, correct. the upper front hose is a 'return to tank', I think the casing next to it is even stamped with a “T”. The 'other return hose' on the back of the FEL valves, that is the Power Beyond port of the FEL valves, goes to what looks like a tank return on the right side of the hydraulic sump, but that is actually the input port for the 3PH. Looks like our machines were identical.

Smokey, I have to take something back that I said earlier. I must have been looking at specs I saved on a set of Cross valves that I was considering purchasing as a replacement for the stock valves on my NT254. I found notes on my original set that states the pressure relief valve is fixed at 1300PSI, not 2600. That explains your 1300 PSI peak.

   My NT254 was plumbed originally with the pump feeding the diverter valve. The diverter split the flow to the power steering on one side and the FEL + 3PH on the other. The fluid to the 3PH goes through the FEL valves and out of the power beyond port of the FEL valves to feed the 3PH, so anything we do in the FEL or 3PH circuits will be limited by the relief valve on the FEL. I also found the FEL to be annoyingly slow, it only gets half of the fluid from the pump so it may still be able to get pressure to lift but the fluid flow rate stinks so it is slow. I replaced my 7GPM Cross valves, with 1300PSI relief valve, with a set of 10GPM valves from Surplus Center, with 2000PSI relief, and moved them upstream between the pump and diverter valve. The FEL movement speed about doubled and I am very pleased! There is one quirk however to having the FEL valves upstream of, and in line with, everything else. If the FEL is in the float position, and you turn the wheels developing pressure in the system via the power steering, or you raise the 3PH with a load on it again developing pressure in the system, the FEL will raise! Someone here can probably explain why. Something to do with the float position ties all ports together and then to the power beyond port, and if pressure developes downstream it translates back upstream to the FEL cylinders?? A small price to pay for the increased performance of the FEL though. About the only time it has really annoyed me is if I have the FEL bucket floating on the ground moving forward to scrape up a bucket of stuff, if I try to correct my heading by using the steering the FEL raises up and I don't get a clean scrape off the ground.