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

 

[RonMar]

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

The block after the FEL valve is a priority type diverter not a divider. Most all the fluid flows down the line to the 3PH control valve. With the 3PH control valve in the hold or lower position, all this flow passes thru the valve body and into the resovoir thru the wall of the resovoir. When you lift the 3PH control lever, this flow is diverted from the resovoir to the 3PH cylinder. A very small ammount of fluid is allowed to pass from the diverter to the steering system. A little may leak by the vane pump and back to the resovoir, but not very much. As soon as you start to turn the wheel, that vane pump/valve at the end of the steering column allows a lot of fluid to flow to/from the steering cylinder. As soon as this fluid is allowed to really flow, the change in pressure this creates in the diverter forces the diverter piston to shift the flow/pressure to the steering system in preference to the 3PH. this pressure does the work, with the vane pump via the steering wheel directing the flow. As soon as you stop turning the wheel, you halt the flow, and the diverter shifts the flow back to the 3PH. That vane pump is just that, a pump. This allows you to still work the steering when the engine is not running. Without hydraulic pressure from the engine pump, the steering vane pump becomes basically a closed system and uses just the fluid in the steering cylinder and lines.

The diverter allows steering to take priority over the 3PH. If you try and lift the 3PH while turning the wheel, the 3PH will slow or not move untill you stop turning the wheel.

 

[Diamondpilot]

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...

Ok guys. On a Jinma 254, not sure about a Foton, it has a open center system. That means if the fluid coming from the pump is not being called on for a use like FEL, 3 point, or steering it just makes a loop to the reservoir. It is always flowing. I put a 10 micron filter that was made for a log splitter on the return side.

Chris

 

[valley]

Greetings Mates and Welcome, Yes! it's cold here 12 above today. The tractor has ATF now, I'll replace it with 32 iso hydro. Is ISO the same as AW?
I saw the suction you put on yours, nice job, I think I would like to put a filter on the return, thinking both that it will be easer to seal and worry of starving the pump. I'm not sure which is the low or no pressure return yet. The fellow that had the tractor put the FEL on later getting the FEL form the same company. Maybe it is a smaller pump, when I get a moment I'll try to find out what size pump it is. I'm not sure what an open system is.
When I get back later I'll read more of what you guys have written and answer more completely. I have a bit of work to do away from the house. Richard

 

[greg_g]

Is ISO the same as AW?

Identical. ISO is an "international" designator, AW is American. What's important is the number that follows.

//greg//

 

[Diamondpilot]

Greetings Mates and Welcome, Yes! it's cold here 12 above today. The tractor has ATF now, I'll replace it with 32 iso hydro. Is ISO the same as AW?
I saw the suction you put on yours, nice job, I think I would like to put a filter on the return, thinking both that it will be easer to seal and worry of starving the pump. I'm not sure which is the low or no pressure return yet. The fellow that had the tractor put the FEL on later getting the FEL form the same company. Maybe it is a smaller pump, when I get a moment I'll try to find out what size pump it is. I'm not sure what an open system is.
When I get back later I'll read more of what you guys have written and answer more completely. I have a bit of work to do away from the house. Richard

If you are refering to my picture it is on the return side. As for the OPEN CENTER System it is a system that is always producing pressure by the pump. If not needed it simply makes its way back to the reservoir. Once called upon to do a job like move the 3 point it directs the fluid to the 3 point valve to do the lifting of the arms. Same holds true for steering and FEL operation.

Chris

 

[Bob Rooks]

Is ISO the same as AW?

Nope, two completely different animals.

The International Organization for Standardization (ISO) is a technical body that works in conjunction with ASTM, SAE, DIN, DNV, and others, to establish world wide minimum standards (this is taking some time, and meanwhile UN climate body suspends DNV's accreditation - Forbes.com DNV got their hands slapped).

Anti-Wear (AW) is the designation given to oil companies for proprietary additive packages that meet certain minimum standards established by SAE through ASTM.

 

[RonMar]

Ok guys. On a Jinma 254, not sure about a Foton, it has a open center system. That means if the fluid coming from the pump is not being called on for a use like FEL, 3 point, or steering it just makes a loop to the reservoir. It is always flowing. I put a 10 micron filter that was made for a log splitter on the return side.

Chris

Chris
I think you are only filtering the fluid that passes thru the steering system. I believe the main flow has always been back to the 3PH valve on the right side of the tractor. I don't think the 200 series Jinma originally had power steering. It was an afterthought/improvement. They added it by putting in the diverter valve located down by your right toe. As I understand it, this selectively re-routes the flow to the steering only when needed. There might be a little leakage thru the steering vane pump, but I would imagine the only real flow you get thru that filter is when the steering wheel is turning.

Richard
I am not specifically familliar with your Foton, but if it is like most of these basic designs, putting in a return line filter is a problem. In order to do it, you need to put it on a low pressure return line with an unobstructed path to the reservoir, AFTER the last valve in the system. Everything upstream of that last valve all the way to the pump will be exposed to maximum system pressure of around 2200 PSI when you lift something heavy with the 3PH. The last valve in these systems is typically the 3PH valve. It's low pressure outlet to the reservoir is thru the side of the valve that is bolted to the reservoir wall. It is basically inaccessable without re-designing how the 3PH control valve is mounted and plummed...

 

[valley]

Well I'm back. I have ISO 32 should I get AW 32? I think the tractor does have an auxillary hydraulic output it is located to the right side of seat it is from there the first owner has a hose going to the FEL. Are you saying there is a vane pump in the steering unit? I haven't got down to look yet, is it driven by the hydro pump.
When the tractor is running and nothing is in operation the fluid is being pumped. there should have a return back to the tank. This would be a low/no pressure line?
I like the idea that the pump is too small that would seem an easy fix. Richard

 

[Diamondpilot]

RonMar, I am guessing your tractor is plumed different than mine.

The way my tractor is plumed goes like this:

Reservoir
Pump
FEL
Diverter Valve

From the diverter valve there is one input, coming from the FEL, then 3 out puts. 1 just goes straight back to the reservoir like a bypass for the open center system, another goes to the steering then back to the reservoir, and the last goes to the 3 point then on to the reservoir.

The hose going from the diverter to the reservoir and the hose going from the steering to the reservoir share a common pipe running down the left side of the tranny. This is where I cut into the system and put a 10 micron return filter. So in essence it is filtering any fluid that has went through the FEL, diverter, steering, and the bypass for the open center return. It is not filtering the fluid that has been called upon to operate the 3 point which just dumps back into the reservoir.

Chris

 

[valley]

Chris, I just reread your last post. There are two or three hydro lines going to the hydraulic tank, I'll get under and around and see if there is a similar set up that sounds good. Should I get AW 32? I have ISO32. Richard