Forum Replies Created
-
Posts
-
I would get a radiator cap of a known pressure. The original was probably something like 6 or 7 pounds. Anything more than that can cause problems.
If you are not running a coolant recovery tank, then the proper coolant level is just above the radiator core tubes when cold. These leaves room in the header for the coolant to expand when it warms up.
You definitely need to find the source of the leak so you can determine the proper fix.
My suggestion is to try and find the source of the leak. Then clean and dry the engine in the suspect area. Check and correct the coolant level if necessary. Start the engine and let it warm up at a fast idle. Leave the radiator cap off and watch the coolant while it warms up. You should be able to observe the flow rate increase the thermostat opens. Watch closely for bubbles. Also watch for coolant to appear at the suspected leak point.
Please let us know what you find and post a picture if possible.
Good Luck.
Since your front end loader and power steering work, we know that the pump is working and there is fluid.
Typically the fluid comes out of the tank under the seat (this also houses the 3pt. piston) and may or may not go through a filter to the pump. From the pump it goes directly to the diverter valve (sometimes called a priority valve). From there, the steering gets the fluid or if it is not needed it gets passed back to the 3pt control valve.
If you have a front end loader it will be inserted into the circuit before the diverter valve. This is usually done with quick connects so that you can uncouple the loader and remove it. You would then connect the two tractor side hoses to each other to provide normal hydraulic pressure to the tractor.
The hose that moves is the pressure line leading from the loader valve back down to the diverter valve. The fact that it moves is telling us that there is a restriction at the far end of the circuit and the hose is being pressurized and swelling slightly. This is normal.
Once the fluid leaves the diverted valve it heads to the 3pt control valve. This is usually a hard pipe but it is possible you have a hose there too. Inside the control valve the fluid either gets routed back to the tank through the pressure relief valve (hold or down positions) or to the lift cylinder (up position).
Since the cylinder is a one way only cylinder, there are two ports. One brings fluid in when the lever is in “up” and is blocked when the lever is in “hold” or “down”. The other port is connected to the flow control knob (under the seat at the front of the tank). Fluid then goes back to the control valve where it is blocked in the “up” and “hold” positions but is allowed to flow back to the tank in the “down” position.
By design the 3pt. can not put down pressure on the arms, it can only lift them. The only down motion is caused by weight on the arms, including the arms themselves. It is possible to force the arms up no matter what the position of the control valve is or whether or not the tractor is even running.
Take a look at the diagrams here: https://www.circlegtractorparts.com Just go to the online parts store and choose the make, model and engine number in the drop down boxes. Then go to the hydraulics section and click on the diagrams and you can see the whole system.
Usually whenever a cylinder hits the end of it’s travel it causes the pressure relief valve to open and you hear a whine or growl out of the hydraulics system. This is usually accompanied by a drop in engine RPM as it picks up a greater load. This is all normal and the since your engine needs more than idle RPM to do this indicates it is working as it should.
As Dave Privett mentioned it is possible that your internal piston has extended beyond it’s normal “maximum” and has become jammed in full up. If this has happened no amount of weight will cause the arms to lower. Usually the equipment end of the arms travel from a few inches above the ground to about 30″ above the ground.
First thing to do is to make sure the flow control knob under the seat is backed off at least a few turns. From sitting in the seat and looking down, clockwise will close the valve and cause the down movement to slow down or even stop if turned all the way. Counter clockwise direction makes the arms drop faster. Make sure it is not turned in all the way.
Second put the lever in the down position (tractor does not need to be running) and see if you can get the arms to go down. They will usually fall under their own weight but standing on them speeds it up.
If you still can’t get the arms down, then about all that is left is to remove the seat and the top cover of the tank so you can have a look at the piston and piston rod to make sure things are OK in there.
It is a little hard to tell from your photos but it looks like the lift arms are already all the way up.
Some questions:
Is the fluid at the proper level in the tank?
If you have power steering, does it work?
The lever is connected directly to the control valve, are you saying there is a hose connected to that valve? If so, where does it go?
There should be 3 detent positions for the lever (down, hold, and up). There should also be an up limiter rod with an adjustable stop. It is supposed to be set so that just as the lift arms get to the top of their travel the stop hits the lever and knocks it out of the up position and causes it to go to the hold position.
Do you have a parts manual for your tractor?
Have you tried putting the lever in the down position and then stood on the lift arms to try and force them down?
Do you hear the pressure relief valve open when you put the lever in the up position?
Based on that, I would say you have a problem in the control valve. I would bet there are no seals on the spool and it works only by close tolerance fit. These valves are not know for high quality tolerances in the first place and yours is likely worn some.
This is based on the concept that there are two ports into the cylinder. One from the control valve for pressure feed to lift and the other for the fluid to escape for lower. The second would take the path through the speed adjust knob (needle valve?) back to the control valve. This is also under the belief that the control valve has the pressure relief valve and the return path to the tank.
IF the speed knob is working properly and can close off the return path then the only way for the fluid to escape the cylinder is to leak past the piston or backward through the control valve. Since the position of the control valve affects how fast it leaks that would indicate the control valve is the culprit.
Of course the piston seal could be leaking too….
That’s a bummer. If you compare your parts diagrams to the one for the Jinma 254 do they look the same?
With the flow control valve screwed in all the way to the stop position and the control lever put in the down position does the lift lower at the same rate as it does with the lever in the hold position?
You’re probably fine with the AW-46. I don’t see that changing to even 100 would do much for the leak-down except to maybe make it take 15 minutes instead of 5.
Unfortunately I don’t see any option other than dis-assembly and inspection. It looks like just O-rings and gaskets. The O-ring sizes are listed in my parts book. If they are in listed in your parts book you can search online for them. Circle-G has a good online parts book. The gaskets can be made by hand if needed so lack of availability shouldn’t be a concern.
Even if the spool or bore are damaged and replacements are not available you should be able to reassemble what you have. Same goes for the piston and cylinder itself.
Looking at the parts diagram for the control valve it would appear that you have to take it all apart to inspect the spool and bore.
Yeah, something is definitely leaking.
I would be inclined to take the block that holds the flow control knob off and have a look inside. It may be one of the o-rings and you may get a better idea of how it works.
You might also be able to pull the cylinder and piston from there. If not, it is quite a pain to take the whole assembly off of the differential and flip it over to get the cover off.
I think you can get the spool valve out of the control without taking it off the tractor.
Don’t forget to drain the fluid. 🙂
Speaking of which, how heavy of a fluid are you using in the summer? I run pretty thin stuff because it is so slow to warm up in the winters of ND (which is most of the time I use it)
Hi Jeff,
This thread is 3 years old, I had to go back and review it to even remember what it was about. If I remember correctly I was able to fix mine by spraying some brake clean and then some lubrication onto the balls that sit between the steel discs. Once they started moving freely all I had to do was adjust free play and all was well.
Do you have disc brakes or drum brakes?
What kind of work are you doing to the brakes?
Most 3 point systems will eventually settle to the bottom.
I’ve never seen a hydraulic schematic for these tractors but if I understand it right, the fluid flows in one port (from the master valve) and out though another port (past the speed control knob/valve.
Based on the quality of machining on these valves, I would bet it it is leaking back past the master valve. About the only other place for leakage would be the piston/cylinder seals.
There are seals between the piston and the cylinder as well as between the cylinder and the “head” (where the flow control knob is). These seals appear to be just O-rings and both are the same size. There is also an O-ring at the open end of the cylinder, but I am not sure what it would be sealing against.
Having never had my system apart I have no specific advice other than to take it apart and inspect for damage to surfaces.
How quickly does yours leak down with a moderate load on the lift? Over night or in only a few minutes?
