loader problems

[willis123]

Hey guys!

I just installed a JM-ZL-20 front loader on my Case 255. I got a really good deal on the loader as it was still new in the crate. I had to fab up all of the mounting brackets though what a pain!! Anyhow the installation is complete and looks great. The bad thing is though the loader doesn't want to go up like at all. Seems like it wants to and sometimes it does a few inches or so.. Sounds like a drain on the motor. Like when your bucket is rolled back all the way and you continue to depress your control lever. All of the other functions work the roll back, dump, and down. The three point hitch also works. Any ideas? I'm a welder and fabricator don't know much about the hydraulic part of it. The tractor is 4x4 with power steering any help would be greatly appreciated!

 

[dex3361]

With the tractor off and the hydraulic pressure relieved take the quick connect fittings loose and reconnect them sometimes when you snap them in they will go on but not open.

 

[Diamondpilot]

How is your fluid level? Did you add any fluid when putting on the loader because as the cylinders fill it will take a good gallon or two out of the sump.

If the curl and dump work fine and the fluid level is fine you may have a couple hoses bass akwards on the lift function. Check it over good. If that is not it the only thing left is the valve itself. Also get rid of the Quick Connects. Especially if you have the Jinma ones on one side and Case on the other. Get swivel fittings and put them in their place. These QC account for about 90% of the hydraulic problems on Chinese tractors.

I have a feeling its something simple you are overlooking or missing. Have a mechanical buddy look it over.



Chris

 

[J_J]

How did you break into the hyd circuit to feed the loader?

Check and make sure that the line from the pump is going to the loader P port, and the PB out is going to the next valve, and the return/OUT is going to tank.

No tee's on the pressure line.

Double check the QD fittings and make sure there is flow through the QD's.



Does the 3pt work normally.

 

[willis123]

The Three point does seem to work fine.... I'm pretty sure its plumb right but with the power steering it kind of makes me wonder.

There is pressure line that comes off the pump to some sort of tee or two way split under the fuel tank. From there one line goes to the power steering and back out to the back of the tractor. The other line coming from the same tee or two way split under the tank runs on the right side of the tractor (loader control side) to the back of the tractor. That's the side I taped in to from the tee to the pressure side of the control valve. Then the three point from the loader valve to the other end of the cut tube. Did I make sense? What do you think?

 

[willis123]

The fluid level seems fine... The loader came full of fluid... Is that typical? Should I have drained every cylinder and them refilled them?

 

[Affordable]

You should have installed like this ,off the pump directly into the inlet of the loader valve,out of the loader valve to the diverter/priority valve valve that feeds the 3-point and steering

Tommy
Affordable Tractor Sales
"Your Jinma Parts Superstore"
Home of compact Jinma, Foton, and Koyker Tractors and Parts, Wood Chippers, Backhoes - Affordable Tractor Sales Company

 

[J_J]

Affordable,

I don't believe that is correct. You can not go to the FEL valve first, for this reason. If you are using the FEL, it could take all the fluid and none left for the steering. You never want the fluid diverted from the steering. It should have priority at all times. Flow should go from pump to divider valve which splits one line to the steering, and the other line to the FEL. Might be something like a 30/70 ratio of the total flow.

 

[J_J]

The Three point does seem to work fine.... I'm pretty sure its plumb right but with the power steering it kind of makes me wonder.

There is pressure line that comes off the pump to some sort of tee or two way split under the fuel tank. From there one line goes to the power steering and back out to the back of the tractor. The other line coming from the same tee or two way split under the tank runs on the right side of the tractor (loader control side) to the back of the tractor. That's the side I taped in to from the tee to the pressure side of the control valve. Then the three point from the loader valve to the other end of the cut tube. Did I make sense? What do you think?

If you have power steering, it is or should be fed from the pump, via a priority valve with relief. If no loader, the second outlet from the divider valve would go back to the 3pt. If you cut this line and fed it to the FEL valve P/pressure port, and then the PB to the other cut piece going to the back you should be good to go. If no PB on the FEL valve, , those valves feed the 3pt from the tank port. However most tank ports go to tank/sump.

 

[Diamondpilot]

Affordable,

I don't believe that is correct. You can not go to the FEL valve first, for this reason. If you are using the FEL, it could take all the fluid and none left for the steering. You never want the fluid diverted from the steering. It should have priority at all times. Flow should go from pump to divider valve which splits one line to the steering, and the other line to the FEL. Might be something like a 30/70 ratio of the total flow.

JJ, I know you know hydros but you are wrong. Every Jinma I have ever seen, 100's are plumbed this way. Mine is this way since 2003 with no issues. There is plenty of flow with its pump.

Mine goes sump, filter/screen, pump, FEL, Remotes (I installed), priority valve to feed steering and 3 point, then back to the sump.

No power beyond port, just input and output on the FEL valve.

Works great with no loss of steering even running my plow off the remotes in the avatar and log splitter and other implements off my custom installed remotes.

Tommy is 100% correct. He knows these tractors inside and out.

Chris

 

[willis123]

My pump is located on the opposite side of the tractor from the loader control valves. If I have to tap in to the pressure line from the pump before the diverter I'm going to need two really long hoses! I Didn't think that was the case that's why I taped in to the second line coming from the diverter that went back to the three point. If I'm wrong please do tell. Thank you to all of you for your help!

 

[J_J]

One question here and that is does the pump flow split before the FEL valve.

It is not logical for the flow to go to the FEL first and then the steering. There almost has to be a splitter to split the pump flow. The steering almost always has a priority flow to prevent accidents. Some tractors have two pumps, one for the steering and one for the FEL and the rest of the system.

I would like to know this for sure.

 

[J_J]

JJ, I know you know hydros but you are wrong. Every Jinma I have ever seen, 100's are plumbed this way. Mine is this way since 2003 with no issues. There is plenty of flow with its pump.

Mine goes sump, filter/screen, pump, FEL, Remotes (I installed), priority valve to feed steering and 3 point, then back to the sump.

No power beyond port, just input and output on the FEL valve.

Works great with no loss of steering even running my plow off the remotes in the avatar and log splitter and other implements off my custom installed remotes.

Tommy is 100% correct. He knows these tractors inside and out.

Chris

What good is the priority valve if the FEL uses all the flow?

 

[J_J]

My pump is located on the opposite side of the tractor from the loader control valves. If I have to tap in to the pressure line from the pump before the diverter I'm going to need two really long hoses! I Didn't think that was the case that's why I taped in to the second line coming from the diverter that went back to the three point. If I'm wrong please do tell. Thank you to all of you for your help!

You say you have a diverter, is it before the FEL valve, and does your steering circuit also feed the 3pt as Diamondpilot says, or is that Jinma only.

A steering priority circuit only gets a small amount of the total pump supply. If you tapped into the steering circuit, that means that you might not be getting fluid when the tractor is steering.

If I am wrong, I am sure someone will correct me, and will someone please send me a Jinma hyd schematic

You want to use as much of the pump flow as possible for the remotes, and most of the flow is through the FEL valve.

You can not tee into the pressure line, but you can interrupt the line and add valves. If the FEL valve does not have PB, then the fluid from the FEL in neutral, will be full flow to the remotes. If you are using the FEL, the remotes will see fluid from the FEL cyl, and fluid not used by the FEL. Not an ideal situation in my opinion.

The FEL should have a PB port and feed the next valve, and so on until the last valve and it does not have to have PB. One good reason is that some valves can not take the back pressure on the tank port.

 

[J_J]

This is my understanding of a priority circuit. It is there to ensure a certain part of the tractor hyd is used for a particular circuit, primarily designed for safety. That circuit is the steering. Ask your self, which circuit would you rather have fluid available. You don't want to be lifting a heavy load and trying to steer, using the same fluid. So therefore, a part of the pump flow is routed through a flow divider to always give the steering circuit fluid. What if your pump pumped 9 GPM, and your priority steering circuit used 3 GPM's.
and say your engine rpm was down low, you might only be pumping about 3 GPM. At least, you will have steering. The steering circuit will take the 3 GPM's, and any left over will go to the other circuit.

That's my story and I am sticking to it.

On my machine, the priority circuit will take over all fluid from the pump for steering. That is at steering lock. If only steering a little, some fluid is available for downstream operation, and in my case, that is the lift and curl circuits. For max lift, steering has to be straight, no flow to the steering cyl.

 

[willis123]

JJ, The tractor is an 89' Case 255 4x4 with power steering. I put a JMZL--20 Front loader on the Case. I know I'm probably killing you guys here with my lack of hydraulic tractor knowledge

The Case has its pump on the left side of the tractor ( sitting on the tractor ) The loader controls being on the right. The pressure line from the pump runs to a diverter? under the fuel tank. On the backside of that are two lines come out of it. One line runs under the steering column to the power steering and back out to the back of the tractor in to the side of the transmission near the submerged filter. The other line from the diverter runs down and along the right side of the tractor and what looks like somewhere under the seat. This is the line I taped in to. Pressure line after the diverter to the pressure on the loader control valve. Then the other end of the pressure line to the "T" on the Loader control valve. Am I making any sense?! LOL Sorry guys! Thank you!

 

[Sweden-Art]

I also think this is strange J_J. Why have a priority valve after the FEL valve? What is there to prioritize? But then again I trust Affordable and his very good knowledge about Jinmas.

On my Chinese Mahindra I have 1 pump for all circuits. Pump > PRV > Flow divider/Priority valve > FEL valve > 3 point. I cant use the FEL and 3 point at the same time. FEL takes the whole flow.

Maybe the Jinma has a double pump, one for steering and one for the rest?

This is interesting though

 

[J_J]

JJ, The tractor is an 89' Case 255 4x4 with power steering. I put a JMZL--20 Front loader on the Case. I know I'm probably killing you guys here with my lack of hydraulic tractor knowledge

The Case has its pump on the left side of the tractor ( sitting on the tractor ) The loader controls being on the right. The pressure line from the pump runs to a diverter? under the fuel tank. On the backside of that are two lines come out of it. One line runs under the steering column to the power steering and back out to the back of the tractor in to the side of the transmission near the submerged filter. The other line from the diverter runs down and along the right side of the tractor and what looks like somewhere under the seat. This is the line I taped in to. Pressure line after the diverter to the pressure on the loader control valve. Then the other end of the pressure line to the "T" on the Loader control valve. Am I making any sense?! LOL Sorry guys! Thank you!

If you have the normal tractor hydraulics, with pump, FEL, 3pt, then you would interrupt the line after the FEL and before the 3pt. You should be using a valve with PB as the first valve., and then add other valve after that connecting the PB outlet to the IN of the nest valve. If you don't have PB, you take your chances by adding other valve downstream, not knowing the back pressure ratings.

Send me a PM, and I will send my PH number.

 

[RonMar]

JJ
The loader valve on the jinma's does not use a return line. It has an inlet and an outlet port, and of course the working ports. It is basically always PB. Regardless of what you are doing with the loader, the same ammount of fluid is flowing out of the loader control valve outlet port as is flowing into the inlet. It is either flowing straight thru, or to-from the cylinders on the loader, or if at it's working limit and the loader is stalled, via the relief valve... It will have no real effect on the steering... every Jinma I have seen is this way, with the loader QC's in the HP line between pump and steering diverter.

I think the term diverter is perhaps not the best term to be used for how the Jinma tractor uses this particular valve to the steering system. I think the term flow control or constant pressure would be better applied. It does indeed divert fluid to the steering from the main line going to the 3PH, but I think it also limits the pressure applied, so the steering valve dosn't respond to pressure changes on the main line caused by lifting impliments on the 3PH. This way they could tap off of a potentially high pressure system that varies in pressure as it feeds the 3PH, to feed a lower pressure steering system and still keep the steering response consistent regardless of what the 3PH is doing.

 

[willis123]

Guys I got it!! It is plumbed correctly! It was the loader control valve body wasn't allowing allowing enough movement for the controls. Bent some areas out of the way and yep she WORKS!!!! Thank you to everyone! I'm so glad it was a simple fix even though it was a pain in the rear! J/J you were correct on the plumbing of it! Thank you! :thumbsup: