Jinma 284 hydraulics failure

George_Martin · Jun 7, 2006

Yesterday, I experienced a complete hydraulics failure -- fel, 3pt, steering. I was doing some light brush hogging (2200 rpm), going downhill, not using any hydraulics, when suddenly the engine acted as if it had a tremendous load and soon died even with the clutch down. It took some cranking to restart, but when it did, I had no power steering. I drove it back to the barn where I realized nothing else hydraulic worked (sure glad I did not lower the fel or 3pt out in the field). The Jinma fel had leaked where the very front hose goes into the single lever control box, but the reservoir was only down about a pint. Pulled the filter under the seat, but it was clean. Disconnected the quick connects for the fel, started the engine, but still no 3pt or ps at all. Reconnected the fel. Right after starting, if I tried to raise the fel it might go up 2 inches very slowly, then stop and not work again. If I tried to lower the fel, it would lower very slowly if I pushed the control just a little, but stop if I pushed it all the way. This morning, I had to move the tractor out of the way, and everything worked fine. This is probably something simple. Your help would be appreciated.

George_Martin · Jun 7, 2006

Yesterday, I experienced a complete hydraulics failure -- fel, 3pt, steering. I was doing some light brush hogging (2200 rpm), going downhill, not using any hydraulics, when suddenly the engine acted as if it had a tremendous load and soon died even with the clutch down. It took some cranking to restart, but when it did, I had no power steering. I drove it back to the barn where I realized nothing else hydraulic worked (sure glad I did not lower the fel or 3pt out in the field). The Jinma fel had leaked where the very front hose goes into the single lever control box, but the reservoir was only down about a pint. Pulled the filter under the seat, but it was clean. Disconnected the quick connects for the fel, started the engine, but still no 3pt or ps at all. Reconnected the fel. Right after starting, if I tried to raise the fel it might go up 2 inches very slowly, then stop and not work again. If I tried to lower the fel, it would lower very slowly if I pushed the control just a little, but stop if I pushed it all the way. This morning, I had to move the tractor out of the way, and everything worked fine. This is probably something simple. Your help would be appreciated.

JohnS · Jun 7, 2006

I suspect you are having seating issues with the quick disconnects. The initial issue sounded like it dead headed, pump has nowhere to push the oil to. The pump will get very hot and eventually blow the seals, usually putting all the hyd oil in the engine. The fittings are not the best, and I've heard of some people removing the sping loading, opting for a little fluid leakage, but I have not tried that. You might find this helpful: web page

JohnS · Jun 7, 2006

I suspect you are having seating issues with the quick disconnects. The initial issue sounded like it dead headed, pump has nowhere to push the oil to. The pump will get very hot and eventually blow the seals, usually putting all the hyd oil in the engine. The fittings are not the best, and I've heard of some people removing the sping loading, opting for a little fluid leakage, but I have not tried that. You might find this helpful: web page

RonMar · Jun 7, 2006

You might have a bad quick connect fitting. That sudden load on the engine was the hydraulic system becomming very restricted. The fluid must ALWAYS flow which is why you never want to try and open the QC's when the engine is running. You may have hit something that partially slid back/opened a QC collar. Doing this while the engine is running deadheads the pump and usually damages it. A cheap safety hint is to place a large ty-wrap/ziptie behind the sliding collar so it cannot be slid back to open/disconnect the QC. This prevents brush or the grandkids playing in the barn from accidently disconnecting one.

IF something happened to restrict the hyd flow enough to shutdown the engine, you may have also damaged the pump. Check your engine oil. If the front pump case or seal is damaged, you could be pumping hydraulic oil into your engine crankcase which will cause that oil level to rise and eventually overflow the crankcase breather.

You said that you took the FEL out of the circuit by connecting the quick connection that comes out of the pump to the one that runs to the diverter valve(located near right foot when seated) and it still didn't work right away? That eliminates any problem with the FEL and narrows the search to the QC's on the tractor or the diverter valve. What sometimes happens is that one or the other check balls in a QC pair will stick and restrict flow. One may have a weaker spring and is overpowered by the other ball and that half closes. This is more likley with QC's from different manufacturers but you said you have a chinese FEL so it probably has chinese QC's.

I like QC's, but I don't like the check balls in them. I have contemplated removing the balls in mine. You can take the check balls out of the chinese quick connects easilly by unscrewing them from the hydraulic hose. Inside the threaded end of the QC you will find a snapring, spring plate, spring and check ball. Remove the snapring and the plate, spring and ball should come right out. I of course would have to do this to all the other QC's this one will mate with as the 2 halfs of a QC pair either both have to have them or both don't but it cant be mixed or the one with the ball will stay closed and no fluid will flow. For the few times I might disconnect mine, I wouldn't mind the little bit of fluid dump while I reconnect the QC's to their other partner to bypass the FEL and overall this would improve fluid flow and lower the no load pressure on the pump.

RonMar · Jun 7, 2006

You might have a bad quick connect fitting. That sudden load on the engine was the hydraulic system becomming very restricted. The fluid must ALWAYS flow which is why you never want to try and open the QC's when the engine is running. You may have hit something that partially slid back/opened a QC collar. Doing this while the engine is running deadheads the pump and usually damages it. A cheap safety hint is to place a large ty-wrap/ziptie behind the sliding collar so it cannot be slid back to open/disconnect the QC. This prevents brush or the grandkids playing in the barn from accidently disconnecting one.

IF something happened to restrict the hyd flow enough to shutdown the engine, you may have also damaged the pump. Check your engine oil. If the front pump case or seal is damaged, you could be pumping hydraulic oil into your engine crankcase which will cause that oil level to rise and eventually overflow the crankcase breather.

You said that you took the FEL out of the circuit by connecting the quick connection that comes out of the pump to the one that runs to the diverter valve(located near right foot when seated) and it still didn't work right away? That eliminates any problem with the FEL and narrows the search to the QC's on the tractor or the diverter valve. What sometimes happens is that one or the other check balls in a QC pair will stick and restrict flow. One may have a weaker spring and is overpowered by the other ball and that half closes. This is more likley with QC's from different manufacturers but you said you have a chinese FEL so it probably has chinese QC's.

I like QC's, but I don't like the check balls in them. I have contemplated removing the balls in mine. You can take the check balls out of the chinese quick connects easilly by unscrewing them from the hydraulic hose. Inside the threaded end of the QC you will find a snapring, spring plate, spring and check ball. Remove the snapring and the plate, spring and ball should come right out. I of course would have to do this to all the other QC's this one will mate with as the 2 halfs of a QC pair either both have to have them or both don't but it cant be mixed or the one with the ball will stay closed and no fluid will flow. For the few times I might disconnect mine, I wouldn't mind the little bit of fluid dump while I reconnect the QC's to their other partner to bypass the FEL and overall this would improve fluid flow and lower the no load pressure on the pump.

bluechip · Jun 8, 2006

Often, two types of quick connects are used, some (Jinma OEM) have a ball check valve and some (Koyker) use a conical shaped check valve. I have seen problems when these are mixed.

bluechip · Jun 8, 2006

Often, two types of quick connects are used, some (Jinma OEM) have a ball check valve and some (Koyker) use a conical shaped check valve. I have seen problems when these are mixed.

George_Martin · Jun 8, 2006

The ps and 3ph do not have QCs. If a QC to the fel were bad I should still have use of the 3ph and ps right? When I disconnected the fel I still had no ps or 3ph. Whatever the problem was it went away overnight but I feel it will likely come back at a bad time.

George_Martin · Jun 8, 2006

The ps and 3ph do not have QCs. If a QC to the fel were bad I should still have use of the 3ph and ps right? When I disconnected the fel I still had no ps or 3ph. Whatever the problem was it went away overnight but I feel it will likely come back at a bad time.