Jinma 254 current owner with Y385 engine help questions

[acadian32]

Good day team... the filter is between the tank and the pump, the year on the engine plate is manufactured in 2007 tractor is blue, the power steering was working, Hazer are you saying the oil pressure sensor even do it has 2 connection only one wire is required? as for the pump rebuilt I found a real good picture on this site showing the right way to position the vanes, last the tractor was working real good one I changed the oils and all filters this all started then i played with the loader control pressure relive valve because the loader lift was not lifting close to what it should and like mentioned on my original thread i read online one could adjust the pressure relive valve by screwing it in and voila for the first time the loader was able to lift the tractor of the ground " all happy" drove it a few more minutes and then all hydraulic stopped... so I back off the control valve screw back and nothing, i figured well maybe the pump was simply weak as i read on line so i took it apart once more and it was then I notice the oil was not coming back from the filter side tank but after thinking about it that line is straight line then up 90 about a foot and connect to the tank so i figure i lose pressure in the loop and figuring the supply is coming form the other side of the tank and tractor. if i blew a seal on the loader would that cause no flow to power steering and 3 point hitch? guys once again a big thank you... Im home all day so I will take some good picture of the tractor today and add notes to picture this should help answer some question.... you guys are awesome i can't do this alone but i sure could follow direction and apply the repair i sure don't lack of tools. I was thinking if I get myself some kind of manual pump connect to control valve since its a the highest point of the hydraulic loop and pump fluid until I cant anymore one would thing my loop would be pressurized? last thin Hazer your right i did notice some Jinma 254 has a hydraulic filter on top of the tank in my case its only a blank plate not 5/8" solid pipe going there so I have to assume its a different model. see page two just added more pictures

 

[acadian32]

 

[quicksandfarmer]

Just to get you oriented: the tank is under the seat. The pressurized part of the system is all on your right when you're sitting on the seat. The unpressurized return lines are all on your left. The fluid flows clockwise.

Different years and models of Jinma put the hydraulic filter in different spots. It can be at the tank, on the suction side of the pump or on the pressure side of the pump. Assuming whoever put the filter housing on knew what he was doing you want that arrow pointing in a clockwise direction.

On my Jinma, if you drain the hydraulics, all you have to do is fill the tank and the pump is primed. The pump is below the tank, the line has no loops or anything. There is no place on the supply side for air to accumulate.

 

[quicksandfarmer]

From the pictures you posted it looks like your filter is on the pressure side and the arrow is pointing in the correct direction.

 

[quicksandfarmer]

To you electrical question: Jinma doesn't color code their wiring, each wire has a number tag on it. You can google and find a wiring diagram which will show the wire numbers.

 

[acadian32]

Okay thank you guys very much the clockwork explanation helps a lot thanks, as for the wire diagram I will check online however no numbers on the wires i mentioned above will keep at it...here a question is it possible if one believe the pump is weak and only change the 4 gaskets in the pump that should fix it? while im waiting for a new pump and gasket kit yesterday i decided the take the pump apart and the vane figure gasket almost like an half 8 looking i used high heat gasket liquid and make a perfectly small bead gasket tried it again nothing darn... so even with new gasket this may not solve a weak gasket is my question?

 

[acadian32]

if one has a bad spool control valve can it cause fluid from getting to the pump? im wondering if i should by pass the spool valve connect the in to the out direct and give it a try? reason im saying this is one on this post said may be o blow a seal on the loader cylinder? thank you.

 

[quicksandfarmer]

You can remove the loader valve from the circuit by connecting the in and out directly to each other. Do not run the pump without them connected, it will ruin the pump.

Here's how the hydraulics work: the pump moves a constant volume of fluid with each rotation. When the hydraulic system is doing no work there is no resistance between pump and tank, no pressure, the fluid flows freely. When the system is called upon to do work the device doing the work increases its resistance to the flow, the pressure at the pump increases and the volume remains the same. The pump can only take about 2,000 psi of pressure, so every device has to have a relief valve to keep fluid moving and ensure that the pressure doesn't exceed that level. On a Jinma the usual devices are power steering, a front end loader and the rear lift, each has a relief valve. The device will usually make a hissing noise when it is relieving pressure. Some Jinmas have one hydraulic pump for all devices, some have two.

If the pump faces excessive pressure several things can happen. If the engine speed is low you might just stall the engine. You might blow a seal on the pump or one of the hoses. Or you might shear off the driveshaft between the pump and the engine.

Your first test is to see if the pump is moving fluid at low pressure. Take the loader out, start the engine, and see if the power steering and rear lift work. If they do, the next test is to see if the pump can create high pressure. You can get the power steering to bypass by cranking the steering all the way over to one side, it should make a hissing noise when you do that.

If you're getting flow and pressure we can look at the loader valve. If not it's an issue with the pump.

 

[acadian32]

hello quicksand, the good news is the driveshaft is okay because when I had the pump on i had the suck 5/8" pipe disconnected to see if the gear rotating all good there i put hydraulic fluid in the pump first just to see it spin. I will bypass the loader tomorrow and try it again silly question should i have the tractor on a good slope to ensure the tank fluid uses gravity to ensure line get full? reason I asked is when one re-instal a pump the pump would be dry along with the 2 primary hydraulic houses. as for my Jinma from my knowledge it only has one pump CBNE317 unless there is a pump in the actual tank like a sump pump?

 

[quicksandfarmer]

Sounds like you have only one pump.

The thing about Jinmas is that every one is slightly different. It's as if they build them depending on whatever parts they happen to have at the factory -- and what mood they're in. (They're like British cars of the 60's that way.)

On mine the pump is below the tank, the pipe from the tank to the pump is wide enough and straight enough that fluid flows very freely and no bubbles can be trapped, nothing else is necessary to fill the supply pipe and the pump with fluid if the tank is full. If I disconnect one of the hoses at the pump, in a few seconds there will be gallons of hydraulic fluid on the floor of the garage and the tank will be empty. (I know this because one time I thought I could take the hose off and put it on again real quick). If I drain the system completely, and then fill the tank, I don't have to do anything more to get the pump working. There may be bubbles of air in the pressurized part of the circuit, but if the pump has a steady stream of fluid at the supply side it will pump fluid and quickly drive those bubbles to the tank.

All of the above is on a level floor.