Foton: Instal an inline filter on hydrolics

[valley]

Greetings, I want to instal a filter inline on the return side of the hydrolics on my tractor. I have a 2005 foton 254,just got it used. I'm not sure which is the line that returns oil the tank under the seat. Foton is made by the same company that makes Jinma. Sure could use some help. Thanks Richard

 

[GuglioLS]

The only way to install a Hydraulic filter on the return line is to use a high pressure filter. Most all, if not every tractor "return" line feeds the TPH valve. What this means is that when the TPH is lifting a heavy or immovable object, the "return" line can and will build pressure up to the system rating which is roughly 2300 PSI more or less so a "standard" return filter will blow apart under these circumstances. That is why most tractor manufacturers typical use a 149 micron suction strainer on the supply line from the tank feeding the suction side of the pump.

Surplus Center does sell a high pressure return filter but it's expensive. Probably not worth it for our tractors. Best thing to do is keep the fill port and vents clean, change fluids every year or two and keep any contaminates from ever getting in the system, especially when filling or topping off with new fluid.

Does your Foton have a suction strainer? if so you are all set.

Larry

 

[valley]

Larry, Yes the Foton has a suction strainer. I bought the tractor used, the screen had been taken out. The strainer was in the oil tank not easy to get at, I don't know how often you have to check and clean them. I'm working on the hydro system, reason, the FEL goes up too slow. Would you just buy and replace the suction strainer? Richard

 

[greg_g]

Jinma and Foton are two different tractor brands, as different as MF is from JD. I say this just so you don't waste money buying Jinma parts, thinking they'll automatically fit your Foton. A few may be interchangeable, but do your homework carefully.

Since there's no screen on your hydraulic pickup any more, I doubt that's the problem with your slow FEL. More often that problem comes from thick/dirty fluid that has begun clogging up the loader control valves. That said, clean thin fluid and clean loader valves will stay that way longer if you either replace the suction screen or add an external suction filter.

//greg//

 

[GuglioLS]

Richard,

Since the internal strainer was removed, now might be a good time to install an external spin on strainer unit. So I see why you are wanting to do that. I just found this one from surplus center, 25 micron strainer it's a 25 micron and is specified for 9 GPM flow. Normally 149 micron is used on the suction side, but since this one is rated for 9 GPM it should work. It also has a gauge to indicate when to replace it. I think you will find 149 micron suction strainers normally last many years because 149 micron (.149 mm) is huge. Since this one is a 25 micron it will trap smaller particles I would think it needs replacement more often. With an indicator to tell you when to replace it that sure sounds like a good thing to me and takes out the guess work.

You say you are working on the hydraulics because the FEL is slow? Have you tried AW32 hydraulic fluid? I see your near Tahoe, so I assume your temps this time of year are on the cold side? Fluid viscosity will affect speed . Do you know what size pump you have? Take a look at the pump, it might have some numbers on it that may help to identify the flow rate in Cubic Centimeters (Milliliters) per rev. Some tractors ship with a low flow pump, as it was not expected to have a FEL on it. Another major factor that affects speed of FEL movement is cylinder size. Larger cylinder ID = slower lift times. If you supply the cylinder stroke, cylinder ID and time in seconds it takes for full travel, the flow rate of the pump could be calculated. Of course the flow rate is dependent on engine RPM.

Good luck with it.

 

[greg_g]

I just found this one from surplus center, 25 micron strainer it's a 25 micron and is specified for 9 GPM flow. Normally 149 micron is used on the suction side, but since this one is rated for 9 GPM it should work.

Each to his own, but I'm not sure if a somewhat higher flow rate potential is a workable trade-off for the significantly higher filtration rate. Personally I'd still go with a 150 micron cartridge, rather than gamble on whether or not I was starving a pump with a 25 micron filter. Especially in cold weather.

The gauge is a good idea. Same concept as the suction gauge on air filters I suppose. I'd buy that filter head, then spin on a triple digit cartridge.

//greg//

 

[RonMar]

Do you have any auxillary hydraulic outputs on the tractor? On my Jinma, I have a single acting outlet port on the rear. This port is for, I believe a dump trailer and is pressurized whenever I lift the 3PH. I made up a 10 micron maintenance filter with quick connects that plugs into this port and returns to a port on top of the resovoir that I added to the filler cap. I plug this thing into the circuit to fine filter the hydraulic flow whenever I am not using the 3PH. I just connect the Quick Connects and lift the 3PH raise lever and the main flow that would normally return to the tank is instead sent thru the filter then to the tank. Connecting this filter causes the 3PH arms to lower all the way and they will not lift as long as the filter is connected.

I replaced the stock in-tank strainer with a little nicer 149 micron stainless one from Surplus Center. I don't think I would feel comfortable putting anything smaller on the suction line of one of these pumps, regardless of the flow rating. I think cold fluid would really effect this small a filter in a suction applcation. In fact, now that my system is cleaned up, the air vent has a dessicant air filter on it and I regularly use the maintenance filter, I am half tempted to remove the suction strainer alltogether, which is another school of thought in the hydraulics industry...

 

[hbaird]

I have an LE200 Jinma. There is a line directly into the base of the hydraulic reservoir from a power steering block that looks to me like a return line. I know if I open the banjo connector with the engine off fluid flows freely from it. I have a power side diverter with 2 outputs. One for the power steering and one for the 3PTH. Fluid out of the pump goes thru the FEL, then to the Diverter. The power steering returns directly back to the reservoir base using what I am calling a return line. I put a 25 micron Northern Tool filter in this line.The 3PTH must return directly to the tank internally . So far all works well.
If I am wrong please tell me.
Harold

 

[RonMar]

I have an LE200 Jinma. There is a line directly into the base of the hydraulic reservoir from a power steering block that looks to me like a return line. I know if I open the banjo connector with the engine off fluid flows freely from it. I have a power side diverter with 2 outputs. One for the power steering and one for the 3PTH. Fluid out of the pump goes thru the FEL, then to the Diverter. The power steering returns directly back to the reservoir base using what I am calling a return line. I put a 25 micron Northern Tool filter in this line.The 3PTH must return directly to the tank internally . So far all works well.
If I am wrong please tell me.
Harold

I am pretty sure fluid only flows thru that return line from the steering when you are rotating the steering wheel, and then only the volume that is being moved out of the steering cylinder...

 

[hbaird]

Thank you Ron for the answer but the answer brings more questions.. Where does the fluid return when the 3PTH is not moving and the steering is also still? If the Divider is a 50/50 divider it would seem that some fluid would flow all the time. I added a tap in the line when I added the filter. A lot more fluid flows out the tap when the engine is running than when the engine is not running. I think the power steering works when I am lifting with the 3PTH so I suspect it is a simple Divider. I am a novice a best on hydraulics with a strong desire to learn.
Harold