Ford 1720 3 point lift problem. I need your HELP!

   / Ford 1720 3 point lift problem. I need your HELP!
  • Thread Starter
#21  
Thanks JC.
The cylinder head cover is not as accessible on my 1720 like on the 1700 model- see attached photo. Tractor deck photo.jpg I will have to remove the entire deck and seat just to get to the head cover. I looked it over last night and it will be a little work but not too bad so I can manage that. One question I had is when I remove the cylinder head cover (looks like 6 bolts) and pull the head cover off, will the cylinder and piston come out with it ALL as one unit?

I am assuming that all I am removing from the tractor is the cylinder head cover and not the entire assembly which would include the case, 3 point arms, and rocker shaft etc. Is that correct? The manual makes it sound like I would need to remove the entire assembly so I need clarification here.

Once the cylinder head cover is off (and assuming the cylinder, piston, and cover are one unit), how does the cylinder come off the head cover?

I viewed your links. From what I read it seems that the cylinder and piston all come out as one unit and come apart fairly easily?

If this is the case then I will be able to see the seal right away to know if it is bad or not. Am I on the right track?

Lastly, I did look closely at the remote spool I added. There is some oil seepage coming from the unit where it meets 3ph spool. Not alot but there is definite seepage. Also, when I operate the remote spool lever, it does stick when I pull it back and the spool valve spool is pushed in - it sticks to the point where it holds the spool valve in. To release it, I have to physically pull it forward to get it not to stick and return to neutral. I doesn't take much effort but it is sticking. On the downward pull, I can go past the neutral point to pull the spool out and and the spool valve will pull out but then the spring tension inside will pull it back to neutral when I release the lever. So, if something is sticking open in the remote spool valve, would that cause me to have no 3 point lift on the arms?

Thanks for you help. Gene
 
   / Ford 1720 3 point lift problem. I need your HELP! #22  
Thanks JC.

Thanks for you help. Gene

Gene,

sorry for all the sheet metal you have to takeout just to have access.

The cylinder head cover is not as accessible on my 1720 like on the 1700 model- see attached photo. View attachment 305798 I will have to remove the entire deck and seat just to get to the head cover. I looked it over last night and it will be a little work but not too bad so I can manage that. One question I had is when I remove the cylinder head cover (looks like 6 bolts) and pull the head cover off, will the cylinder and piston come out with it ALL as one unit?
yes, the cylinder is attached (sealed) to the head by the action of two big fat O-rings. I bought extra but they were in very good shape, so I have two spares. O-rings occupy a groove and you can take off easy without damaging them. You can take the cylinder off of the head and that exposes on of the big o.ring. You can push the piston out by using hammer handle to push it out. do be careful with the orientation of the piston and the orientation of seal lip. cylinder is beveled/chamfered some to fit in to the back of diff cover. make sure the ram rod upon reassembly is inside of the cylinder and faces the red color of the piston (concaved.)

I am assuming that all I am removing from the tractor is the cylinder head cover and not the entire assembly which would include the case, 3 point arms, and rocker shaft etc. Is that correct? The manual makes it sound like I would need to remove the entire assembly so I need clarification here.
That is right all you are taking out is the cylinder head with piston and cylinder attached,.

Once the cylinder head cover is off (and assuming the cylinder, piston, and cover are one unit), how does the cylinder come off the head cover?
You just pull them apart, it is is a tight fit but no tool will be necessary.

I viewed your links. From what I read it seems that the cylinder and piston all come out as one unit and come apart fairly easily?
yes.

If this is the case then I will be able to see the seal right away to know if it is bad or not. Am I on the right track?
As soon as pull them apart and push the piston out by a wooden rod (mallet handle) you will be able to see the seal.

Lastly, I did look closely at the remote spool I added. There is some oil seepage coming from the unit where it meets 3ph spool. Not alot but there is definite seepage. Also, when I operate the remote spool lever, it does stick when I pull it back and the spool valve spool is pushed in - it sticks to the point where it holds the spool valve in. To release it, I have to physically pull it forward to get it not to stick and return to neutral. I doesn't take much effort but it is sticking. On the downward pull, I can go past the neutral point to pull the spool out and and the spool valve will pull out but then the spring tension inside will pull it back to neutral when I release the lever. So, if something is sticking open in the remote spool valve, would that cause me to have no 3 point lift on the arms?

Before I take out the cylinder head I put my gauge where I showed, start the tractor and start to manipulate all the hyd control and watch the gauge to see if shows fluctuation. take note and report.


JC,
 
   / Ford 1720 3 point lift problem. I need your HELP! #23  
If you have an open center hyd system, and the pump is working, you only have flow.

You only have pressure when the flow meets some resistance. If no resistance in the open center circuit, then the fluid is passing through all valves to tank.

If you have pressure on the loader enough to lift the frot of the tractor, then you have at least good pressure.

So if the pump is deemed good, and you try to use the 3pt, and nothing happens, then the valve spool is not working, or the fluid is slipping by the piston or through it.

Don't remember what you said about the remote, but perhaps you are sending all the fluid from the remote to tank and bypassing the 3pt.

You said you added a remote, how did you connect the hoses?

Did you use PB outlet on the remote to feed the 3pt, and did you run the OUT port to tank?
 
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   / Ford 1720 3 point lift problem. I need your HELP! #24  
If you have an open center hyd system, and the pump is working, you only have flow.

You only have pressure when the flow meets some resistance. If no resistance in the open center circuit, then the fluid is passing through all valves to tank.

JJ,

The first thing that happens on hyd pump discharge is the pressure relief device (meeting resistance)and then to the spool. it is open centered at the spool and fluid not used returns to diffy reservoir. The pressure is developed at the the relief device before going to open center spool.

JC,
 
   / Ford 1720 3 point lift problem. I need your HELP! #25  
Not true.

The pressure relief does not activate until the pressure on the cyl is maxed out at a set relief pressure.

The purpose is to protect the pump from gong to over pressure and causing damage.

It may be a regulator, but only at the high end.

If you don't have any valves activated, why would you want to regulate anything. the fluid just flows from pump to tank through all valves in series.

Did I miss something when I slept-ed at the Holiday INN last summer?

Relief valve - Wikipedia, the free encyclopedia

The relief valve at maxed set pressure becomes the path of least resistance.

Any part of the fluid through a valve not used is just passed downstream.
 
   / Ford 1720 3 point lift problem. I need your HELP! #26  
You might have :), I don't know JJ,

The spring stiffness at pressure relief sets pump pressure (adjustable by shims or adjusting a dial in or out ). Above that pressure relief happens and fluid is diverted to sump to avoid a dead head condition. That is exactly how my 1700 or kubota is configured.

JC,
 
   / Ford 1720 3 point lift problem. I need your HELP! #27  
Most of what you said is correct, but the relief valve is spring loaded sitting on the seat doing nothing but blocking the fluid from going to tank via that route.

When the pressure is developed anywhere in the hyd system, caused by load, the flow continues until the set pressure is met, and then the relief valve is tripped opened and allows the excess fluid to flow to tank.

When the excess pressure is removed, the relief valve blocks the fluid through the relief valve.

The relief valve activates after the fact of loading not before.

The relief does not set flow pressure, it allows for over pressure to be relieved.

If the cyl is only using about 75% loading, the relief valve may never activate. So in essence, you would not even know it is there.

It is just blocking off a possible exit fluid path.
 
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   / Ford 1720 3 point lift problem. I need your HELP! #28  
Okay. We're not too far off from one another.

What would happen if I remove the spring from my relief device?. if I don't provide an artificial resistance to the flow then the pump pumps at some gpm at the pressure the pipe, valves, elbows or whatever else in the circuit develops. As the result flow will be higher at much less pressure developed. Of course we're talking positive displacement pump (gear, screw or diaphragm). I f the pump was centrifugal then I can dead head the pump for a few second without damage to figure out max head developed. As a matter of fact that is how the pump impeller dia is measure without taking the pump apart as part of Test and balance of hydronic system.

jc
 
   / Ford 1720 3 point lift problem. I need your HELP!
  • Thread Starter
#29  
Don't remember what you said about the remote, but perhaps you are sending all the fluid from the remote to tank and bypassing the 3pt.

You said you added a remote, how did you connect the hoses?

Did you use PB outlet on the remote to feed the 3pt, and did you run the OUT port to tank?

I did add a power beyond remote. The one I used was the Ford factory single spool remote that came as an accessory you could purchase for the tractor. To mount it, you take the cover plate off the 3 point hitch spool and it bolts directly to the side of it. Below the remote spool are two hard lines that go to the back of the tractor to plug your hydraulic equipment into. To mount the remote, there are no lines it just bolts directly to the 3 point hitch spool. Like I said in an earlier post, I did look closely at the remote spool I added. There is some oil seepage coming from the unit where it meets the 3 point hitch spool. Not alot but there is definite seepage. Also, when I operate the remote spool lever, it does stick when I pull it back and the spool valve spool is pushed in - it sticks to the point where it holds the spool valve in. To release it, I have to physically pull it forward to get it not to stick and return to neutral. I doesn't take much effort but it is sticking. On the downward pull, I can go past the neutral point to pull the spool out and and the spool valve will pull out but then the spring tension inside will pull it back to neutral when I release the lever. It never used to stick like that until my hydraulic problem developed. So, if something is sticking open in the remote spool valve, would that cause me to have no 3 point lift on the arms?
.
 
   / Ford 1720 3 point lift problem. I need your HELP! #30  
The torque on the bolts that mount the valve should be equal as they might warp the housing and cause the spools to bind.

Some spools are designed for friction lever which allows the lever to stay where you left it.

A spring center spool is supposed to return to center neutral when released.

I would reseal the valve to block and use correct torque numbers for the bolts.

What happens is when the lever sticks open, and nothing on the rear hoses you are blocking some or all of the pump fluid from passing downstream. This will cause some heating and if left in full lever, the relief will stay activated at that valve or a relief upstream.

The first relief valve is the master relief, and the other valves should be set the same.
 
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