International 686 steering need help

Alright so I have a international 686 diesel tractor d312 German diesel two oil filters. So the question is that the tractor has no steering whatsoever the steering wheels just spins in circles. My pto does work I have changed the hydraulic filter and that didn’t even help it a little. I have no clue on what can be causing this it’s very strange. Also my 3 point arms don’t move and they don’t budge or nothing they are stuck as high up as they will go and will not come down. If anyone can help me with this I would really appreciate it.

Thanks,

greentractors77
 
Is there pressure at the remotes? This almost sounds like the pump on the clutch side is not turning or working.PTO does not use that pump. Flow control stuck open? A 3000 Psi gauge on the fitting of the pump cover will tell a lot.
 
Yes there is pressure at the remotes I think it was about 1900 which is way low. I’m thinking a pump to but is there anything else on that steering setup under the dash that could be stripped or broken. I would think that it would eventually have to stop instead of spinning and spinning.
 
The hydrostatic steering system uses the steering wheel to turn a hydraulic pump. This is a modest manual pump that pumps in either direction. Its output is used to make flow/pressure that the steering piston/controller in the front bolster activates. this in turn is amplified in pressure to move the steering Left right. If the "hand pump" has no fluid in it, or is internally broken, it will just spin. Jim
hand pump.
 
Nope they will spin till the cows come home. Since you changed the filter and the fluid level is full at this point too I am guessing you checked that. .then you are pretty much down to the MCV or the pump on the back of it. there is one other option that would be if the pilot valve is not working correctly. Not sure where it is on that tractor though on the 06,56,66 series it is under the fuel tank has a couple of lines coming off of it. Though I would doubt it as I have only had to put a new seal on the end cap to one in 45 years. It does sound like you have lost prime to the pump. Adding the 5 gallon over fill would fix any leaks in the internal tube in there. I am going on the basis that when you changed the filter all the o-rings and gaskets were put in place and correct order since I can not see it from here. If you could put a gage on one of the steering lines at the cylinder you could verify any pressure there. I doubt your hand pump is bad also since I have only had to reseal a couple in the last 40 years. And those were all in the last 10 year. IF you had a leak under the dash it would rain when cold and might quit once warmed up . Our 1466 started doing that right at the start of planting one year and would not always leak so we completed the season and I pulled it to reseal now works fine.
 
Okay so your thinking the MCV pump or the pump the main pump the one that has one piggy backed so either the pump that is piggy backed or the one the piggy back mounts to I’ll probably just replace both of them. I can get to them on the left hand side of the tractor sitting in that access panel on the side of the transmission correct? Where is the mcv located at or is that the one that piggy backs on the main one?
 
(quoted from post at 15:53:12 09/18/20) Okay so your thinking the MCV pump or the pump the main pump the one that has one piggy backed so either the pump that is piggy backed or the one the piggy back mounts to I ll probably just replace both of them. I can get to them on the left hand side of the tractor sitting in that access panel on the side of the transmission correct? Where is the mcv located at or is that the one that piggy backs on the main one?

That's at least a 1000 bux to replace the pumps. I am replacing my 2606 main pump with a 17 gpm cessna style pump that Abilene ag parts quoted at 340 plus tax. I asked about the 5 gpm mcv pump that is attached at the back of the main pump and it was quoted at 472 plus bux. The mcv runs the steering but I had a weak main pump for the loader and now.

I don't think that is your fix. Does the system make any noise when you turn the wheel? I dealt with a similar issue but I forget what fixed it. Seems like I flushed the pilot valve and eventually replaced the hand pump seals when the top one started leaking. It might have been the over filling with hytran.

Try cracking loose one line at a time on the hand pump and pilot valve to see what you get other than hytran blowing all over the place. You might just have some gunk in there which may have been my problem that cleaning fixed.
 
Before you start just replacing parts. The MCv is the square plate on the side with a couple of lines coming off from it. Probably on the left side by the step or just ahead of it. The gear could have come off the shaft too. I did have that happen once. The main pump is probably not bad as it runs the 3pt ,scv(select control valves). the little pump on the back of it is where I would suspect pump problems as it runs the power steering and trans lubrication. Now you said the pressure was only about 1900 on the scv. Was this at idle or warmed up and rated pto speed. IF at idle or less then rated speed then your pressure may still be fine. You really need a flow rater to check a pump. IT will load it while checking rate of flow in GPM. Keep in mind this is an opend center system meaning it will only develop as much pressure as it needs to lift an implement. So if you check pressure only needing 1500 psi to lift it then that is all you will see on your gauge. put a gauge in the back of a coupler and with it plugged in then pull the lever with oil warm and engine at rated speed. You should then get your pressure reading in the correct range for that tractor probably around 2200-2600 psi.
 
Okay so your thinking the pump that is piggy backed to the main pump so to get to that can I take of the side plate underneath the clutch pedal and access it from there or do I have to split it? Thanks for y’all’s help
 

I just took mine off Thursday. You will lose all your fluid unless you drain it first. Half inch wrench takes off the 2 hydraulic lines which have orings behind them. The bolts around the plate are 9/16s. You will probably ruin the gasket prying the plate and pump straight out. The four 5/8s bolts hold the pumps to the plate. There are two orings between them and you could have a bad one leaking. If you remove the 4 pump bolts before the plate then I can tell you the pump will fall on the ground with the orings lost in the grass. Maybe the mcv pump needs flushing or has a bad oring. Just be prepared to go to the gasket and oring store when you put it back together. Good luck.
 

Here is a pic if it loads. The mcv pump is attached to the back of the main. The main has an extra hole for fluid passage. The flat part on the right of the first pic that isn't shown is where the plate bolts up.

mvphoto62100.jpg


mvphoto62101.jpg


mvphoto62102.jpg
 
Hold up guys no I repeat no MCV on a 686. The piggy back if I remember does the three point on those and the main pump has a priority valve that takes from the main pump 3 gpm for the
steering. Need to look at the priority. Agreed you can see what the pumps are doing from fittings on the plate that holds the pump on the clutch side.I usually don't work on that new of
stuff.
 
Okay so what do I need to do to get to that pump? Can I drain
the oil take that side plate off under the clutch pedal and then
get to them there? Thanks for the help
 


Roger has a point. Do you have 1 hose or 2 coming off the plate? That might tell you how many pumps are in there. You can unbolt the hose/hoses and all you will lose is what is in the hoses. Not sure what that will tell you though. Guess I would start with open up the return from the steering pump to the pilot valve and crank on it to check the flow. Then check the other side and you will probably have to turn the wheel to get the flow started. I'm kinda guessing here and there are others who know a whole lot more. I never had a chance to flow test mine since it was going to cost me a hundred bux in fittings and a guage.
 
I want to say I had less than 50$ in the gauge and fittings. Got them from Fleet Farm, Tractor Parts ASAP also has them, there is online also. Just make sure the gauge can handle 3000.
That system should be a tad less than 2000. I do believe there is a problem with the priority.Just taking it apart will not tell you what is happening. There is other reasons for the three
point to fail but you really need to see what is coming out.
 

That is good to know Roger. When I went through my 2606 hydraulics I was having to go to the big buck hydraulic store for everything or caseih..

My 2606 hydraulics are a variation of the 560. 606, and 656. Don't know how they compare with the 686.

I don't remember all the problems besides the leaky hand pump that I replaced the seals on but I did flush out the pilot valve and ended up replacing a weak or plugged bypass that was in the corner of the tank under the cover under the seat. Don't remember what that fixed but it did something.
 
I know this is a change of subject but means I’m going to fix
the steering and all do the 666 ih models use the same
complete wiring harness as the 686 because all I can find is
for the 666 series.
 

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