3-point 'suddenly' quit

[dcsey]

I'm pretty new to tractors; bought an 8N mainly for brush hogging and snow removal since my dad had the implements laying around unused. Hydraulics/3-point were working fine until one morning I tried them and nothing. I mean that quite literally. The evening before everything worked fine. The next morning, you'd think the lift control lever was hooked to nothing.

The previous owned had recommended that I change the fluid and give the inside a good cleaning. Based on color, the fluid was definitely water contaminated and, as he had indicated, had all sorts of sludge inside. But, at that point, I had had it less than a week. I gave it a good cleaning and fresh fluid, but that didn't help. Searched around multiple forums. No leaks that I could see with the dipstick-side inspection plate off. When I move the lift control lever, it doesn't seem to move much at the pump intake valve.

Just hoping for some $.02 before I start throwing money around. Thanks in advance.

 

[Ultradog MN]

Starting with the simplest things first...
Is the PTO lever engaged?

 

[dcsey]

PTO is engaged.

 

[kldenny01]

When my 2n did the same thing it turned out to be the lift control arm came loose from the pump control arm. I removed the right inspection cover, reached in followed the arm down and found it loose. The lift arm is a squared U shaped fork pointing down. The pump control arm is shaped like a dog bone and the fork fits over the ends. When I reached in I could find the pump control arm and with motor running move and make the 3 point work.

 

[Bruce (VA)]

As UD said, check the simple stuff: PTO engaged, clutch out & fluid level.

If all that checks out, then you could have a bad friction disc, stuck/dirty exhaust valve, a blown top cover gasket, a leaky pressure relief valve or the control rod is loose from the pump. Take the inspection plate w/ the dipstick off. Reach in & make sure the control rod is connected. If it is, move the touch control lever & make sure it moves the control rod. If the control rod is connected & the touch control lever doesn't move it, the friction disc might be bad.

Post back w/ what you find. If none of these suggestions work, then we will go to troubleshooting level 2.
75 Tips

 

[bigbleeker]

Make sure your not in draft control my neighbor just had his in draft and he would get nothing put in postion control back to work.

 

[old]

Had that sort of problem on an 8N I had in for service. Found that the control was not moving the valve so no lift. So with it running carefully reach in the try to move the control with your hand. If you can make it lift that way you have something out of place or broken etc

 

[dcsey]

All the simple stuff seems proper. I've actually had the top cover off and the pump out. Wouldn't hurt to replace the piston and hone the cylinder, but my main focus here is on why it just suddenly quit. Didn't do anything internal to the pump, just cleaned more sludge. The control rod is in place, but I did notice that when you move it from "down" to "up", it moves forward (towards the front of the tractor, probably almost two inches of travel). When I move the intake valve, it moves out (towards rear of tractor). When the pump is working, does it force the intake valve out (to the rear)? And when you "lift" the control lever, it pushes the valve back in? Again, ~2 inches of travel on the lever with the cover lifted off, but little to no movement when assembled and in place.

 

[Bruce (VA)]

Is everything back together now ? If so,
what are the results of the things I
suggested you look at in my previous post?
75 Tips

 

[Tim PloughNman Daley]

Did you replace the safety relief valve? Often times that is a likely suspect. What color is the oil? Any bubbles from the base? Any oil dripping down from the cylinder? Good advice already given from the others. Put lever in POSITION control (straight up) and engage PTO lever. Report back with results...

[i:654c4848f0][b:654c4848f0]<font size="4">Tim *PloughNman* Daley(MI)</font>[/b:654c4848f0][/i:654c4848f0]<table width="100" border="1" cellpadding="0" cellspacing="0" bordercolor="#000000"><tr><td height="25" colspan="2" bgcolor="#CC0000">

<font color="#FFFFFF" size="3">*9N653I* & *8NI55I3*</font>​

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</td><td>

</td></tr></table>

 

[dcsey]

PTO engages fine, clutch out and, at this moment it has fresh Orschlen "Universal Heavy Duty Tractor Hydraulic &amp; Transmission Fluid", which meets Ford M2C134-B specs. I don't actually have it full right now; added 4 gallons.

Beyond that, I'm not sure what the friction disc is or how to check it. The exhaust valve is connected to the inlet valve, correct (the control rod is connected to the latter, and closing one opens the other)? Assuming I'm correct there, they seemed to operate ok by hand when I had the pump out. When assembled, there seems to be hardly any movement when moving the control lever. The top cover gasket is new. I'm also not sure how to check the pressure relief valve. Probably something I should have gone ahead and replace while I had things apart, but just a matter of waiting when I have to order things online.

I don't see any oil leaking from the cylinder, although perhaps I should remove the driver side inspection cover to get a better look??

 

[Bruce (VA)]

" I'm not sure what the friction disc is or how to check it."

I told you how to check it in my first post. This is what I said:

Take the inspection plate w/ the dipstick off. Reach in & make sure the control rod is connected. If it is, move the touch control lever & make sure it moves the control rod. If the control rod is connected & the touch control lever doesn't move it, the friction disc might be bad.

Do you have a set of manuals? See tip # 39. Your work will be a lot easier if you do.

" I'm also not sure how to check the pressure relief valve. "

That's not likely to be your problem. But it's easy enough to check. If it's totally blown out, you will have a lot of turbulence at the rear of the pump. To check for a leak, lift a heavy implement, turn the tractor off & put a ½ inch clear plastic hose on the end of the valve & stick the other end of the hose through the inspection port. Wiith pressure in the pump, a bad valve will likely show some fluid in the hose.

" Probably something I should have gone ahead and replace while I had things apart,"

Yep.


" although perhaps I should remove the driver side inspection cover to get a better look?? "

Doesn't matter which one you remove, but get a flashlight & an inspection mirror. Lift a heavy implement & look inside w/ the tractor running & the PTO engaged to see if you notice oil running from the top cover. If oil is running steadily from the top cover the chances are the lift cylinder needs to be rebuilt. It’s less likely, but a possibility, that the top cover gasket is bad. (It’s very difficult to detect the exact source of the oil leaking inside of the top cover while looking through the inspection port). If no oil is running down from the top cover, look at the rear of the pump in the oil with the load still on it and see if you notice turbulence in the bottom. (Some movement of oil will be normal with the PTO shaft turning). You could have a weak pressure relief valve which will be detected by turbulence in the oil.

Post back w/ the results of these tests.

75 Tips

 

[JMOR]

(quoted from post at 21:05:57 06/06/15) All the simple stuff seems proper. I've actually had the top cover off and the pump out. Wouldn't hurt to replace the piston and hone the cylinder, but my main focus here is on why it just suddenly quit. Didn't do anything internal to the pump, just cleaned more sludge. The control rod is in place, but I did notice that when you move it from "down" to "up", it moves forward (towards the front of the tractor, probably almost two inches of travel). When I move the intake valve, it moves out (towards rear of tractor). When the pump is working, does it force the intake valve out (to the rear)? And when you "lift" the control lever, it pushes the valve back in? Again, ~2 inches of travel on the lever with the cover lifted off, but little to no movement when assembled and in place.

ounds like you are saying that it doesn't move the rocker enough to make it lift. Reach in and move it with your hand until it touches pump casting &amp; see if you get lift. As long as you keep hands out of middle of pump there is nothing to hurt you.

 

[dcsey]

I can't get any movement by hand. Here's a video showing the control rod movement:

https://www.youtube.com/watch?v=fyXGC7wih2s

Bruce, since the lift control plate is keywayed (not sure if that's actually a word, but anyway.........), is it safe to assume it's pressed on and will take an act of congress to remove or is mine perhaps just being stubborn?

 

[JMOR]

(quoted from post at 17:56:19 06/07/15) I can't get any movement by hand. Here's a video showing the control rod movement:

https://www.youtube.com/watch?v=fyXGC7wih2s

Bruce, since the lift control plate is keywayed (not sure if that's actually a word, but anyway.........), is it safe to assume it's pressed on and will take an act of congress to remove or is mine perhaps just being stubborn?

our video is marked "private", so no can view. Yes, keyed &amp; corroded to shaft. If shaft at nut is turning when you move touch control, don't worry about it......not your current problem.

 

[dcsey]

Try again please.

 

[JMOR]

(quoted from post at 18:37:39 06/07/15) Try again please.

on't know what you are doing while I watch the Scotch yokes splatter oil, but I'll guess you are moving the touch control lever. Loosen the 4 bolts attaching the quadrant to top cover &amp; slide it all the way to the rear (there are slotted bolt holes), Now try it.
Another question.........you said that you had the pump out......could you push inward at control rod attachment point enough to make that rocker touch pump casting as shown in picture that I sent earlier?

 

[dcsey]

Yes, just moving the control lever up and down. Visually, it almost looks like it's on a cam up top (more up and down movement) than horizontal.

In one of my earlier posts, I mentioned that, with the pump removed, I could only move the rocker out, towards the rear of the tractor, but that moving the control lever to the "up" position (with the top cover removed), it would move the control lever forward towards the front of the tractor. It seemed to me that they were working in opposite directions, so I guessed that when the pump was engaged, it forced the rocker/inlet valve out (hope I'm making sense). In your pic, it looks like it's out "by default".

@Bruce, it looks like we can count out the friction disc. Thanks.

 

[JMOR]

(quoted from post at 20:02:43 06/07/15) Yes, just moving the control lever up and down. Visually, it almost looks like it's on a cam up top (more up and down movement) than horizontal.

In one of my earlier posts, I mentioned that, with the pump removed, I could only move the rocker out, towards the rear of the tractor, but that moving the control lever to the "up" position (with the top cover removed), it would move the control lever forward towards the front of the tractor. It seemed to me that they were working in opposite directions, so I guessed that when the pump was engaged, it forced the rocker/inlet valve out (hope I'm making sense). In your pic, it looks like it's out "by default".

@Bruce, it looks like we can count out the friction disc. Thanks.

here is a spring behind the intake valve that pushes it out (default position). You are working against that spring to push it IN for lift. Top of control arm is an eccentric on the touch control shaft, so some up &amp; down movement is to be expected.....it does nothing.

 

[dcsey]

Would a bad spring on the intake valve necessitate a rebuild of the hydraulic pump?

 

[JMOR]

(quoted from post at 09:41:44 06/08/15) Would a bad spring on the intake valve necessitate a rebuild of the hydraulic pump?

o

 

[Bikerider]

Following this thread since I am having a problem like this with my 9N. Wondering , does your PTO shaft rotate when engaged and the tractor is running? My 9N just quit turning the PTO and the lift pump doesn't run so no lift. we may have the same problem and I suspect it is the gear that drives the PTO shaft.

 

[dcsey]

I'll get the pump back out tonight and confirm. Would this be the part I''m after?

http://just 8n's/8N697-Years1948-52-Spring-Hydraulic-Intake-Valve_p_2478.html'

 

[JMOR]

(quoted from post at 10:11:37 06/08/15) I'll get the pump back out tonight and confirm. Would this be the part I''m after?

http://just 8n's/8N697-Years1948-52-Spring-Hydraulic-Intake-Valve_p_2478.html'

es, 8N697.

 

[dcsey]

$5 for the spring, $6.15 for shipping, but it's on its way. Thanks for all the input. I'll check back in with results (or requests/questions). Thanks again.

 

[dcsey]

After dropping the pump, here's the position of the rocker.

I can move it out, as below, but I cannot move it in so that the lever end contacts the housing. If I remove the pin and remove the rocker from the other side, the inlet valve goes in without any problem. Something stuck on the other side?

 

[JMOR]

(quoted from post at 11:32:37 06/13/15) After dropping the pump, here's the position of the rocker.

I can move it out, as below, but I cannot move it in so that the lever end contacts the housing. If I remove the pin and remove the rocker from the other side, the inlet valve goes in without any problem. Something stuck on the other side?

don't know what you mean by, " remove the rocker from the other side,". Please re-word or explain further.

The exhaust valve that is pinned to the rocker can be un-pinned &amp; pulled completely out of pump with only finger pull.

 

[dcsey]

The exhaust valve will not budge on mine. I can press it in some, but it's not coming out willingly.

 

[JMOR]

The exhaust valve that is pinned to the rocker can be un-pinned &amp; pulled completely out of pump with only finger pull. Pull it out. Looks/sounds like it is stuck.

 

[dcsey]

Sorry, I edited my last post when I saw the comment about the exhaust valve. It's kinda hard to concentrate with a toddler bouncing off the walls.

The exhaust valve won't budge even when using vice grips.

 

[JMOR]

(quoted from post at 12:56:22 06/13/15) Sorry, I edited my last post when I saw the comment about the exhaust valve. It's kinda hard to concentrate with a toddler bouncing off the walls.

The exhaust valve won't budge even when using vice grips.

ith a good light &amp; maybe a stiff wire you can look/feel around the front of the EX valve/bushing to determine if some foreign object is in the hole/port of the bushing in front of the spool. The reason you can push it in is a spring inside the spool. Pulling out, you are trying to move the stuck spool.

 

[dcsey]

Hole looks clean, but I can't get it to move at all.

 

[JMOR]

(quoted from post at 14:49:14 06/13/15) Hole looks clean, but I can't get it to move at all.

ery likely rust/corrosion. You don't want to scratch up the bore/bushing with metal object, but you might use hard plastic or wood dowel to go in beside the little rod and hammer the spool inward enough to break it loose &amp; then maybe push pull and little by little free it up.

 

[dcsey]

Well, using a small brass hammer, one no-too hard hit on a 3/8" deep well socket and it came out scary-easy. The pump is assembled now, so I guess it's back in the tractor and see how it works. Fingers crossed.

 

[dcsey]

Perhaps some quick theory of operation as well. It looks like the full range of motion (lever side of rocker against pump case) is achieved with the touch control lever only halfway up. Does that sound correct?

 

[JMOR]

(quoted from post at 16:52:02 06/13/15) Perhaps some quick theory of operation as well. It looks like the full range of motion (lever side of rocker against pump case) is achieved with the touch control lever only halfway up. Does that sound correct?

t will be different whether in Position control mode or Draft Control mode &amp; can be altered by loosening the 4 quadrant mounting bolts and sliding quadrant fore &amp; aft on slotted holes. Did you find rust &amp; corrosion?

 

[dcsey]

Honestly it looked fine. As easily as it came loose, it's hard to imagine how it could have been in so much of a bind. But, (drumroll.....), IT WORKS!!!!!