Internal Hydraulic rods/roller

[4040t]

Hello again
I have made a start having a look for what may be wrong with the hydraulics on our SM
There is a lot of play in the rod to the spool valve
The inside of the cover was well and truly covered with muck, and after a quick wash off, it is obvious that at least one fault is the roller on a lever
The quadrant type thing shows signs of scoring as well
I can re-engineer it, but I was wondering if anyone knows what the diameter of the roller is when new?
I have never had anything to do with major hydralics before, so may have described some parts incorrectly!
The picture should show this problem
Any information would be much appreciated
Thanks,
Adrian

[Brian]

You have the diameter of your roller ther in the picture. Just measure the unworn area beside the pin head where the roller has never been in contact with the Position control cam.

Check out the "Hydraulics" article on the Fordson Wiki. It gives you setting methods and measurements. Be careful to use the measurement and procedure for the right Super, early or New Performance, as they differ.

Codes for the Wiki are "fordsontractorpages" and "dotty".

http://www.fordsontractorpages.nl/wiki/ ... ePage.html

[4040t]

Thanks Brian,
I'm glad you have been able to confirm my asumption
I made a new roller/pin in the week based on the size at the ends, though I have made the new one oversize to match the wear in the quadrant part, hopefully putting the centreline of the pin in more or less the same place as new (I hope!)
I had to use a diamond file to clean the quadrant up to a usable state as the casting was vary hard in this area
I have used the wiki information (thank you) along with whats in the ford manual to set it all up earlier, so hopefully it will work ok now, though the setting info in the ford book is rather confusing as it says when setting the non draft control to have the lift lever at the bottom of the hand lever quadrant. This just didn't seem to work, on looking at the wiki it seems to suggest to set it at the stop at the bottom of the quadrant. I hope I have this interperated correctly.

A pic of the new roller assembly



Also I have been unable to get the flow control valve out. I have tried all sorts with no luck, it was well and truly stuck
So, I made a blanking plate and used a grease gun to pump the valve out from the other side, so to speak.
If you try this, you will also need to make/fit a piece of 3/8 rod to block off the bore beside the valve hole (with a cross hole to hold it in) as there is a hole between the two bores that will let the grease out.
Hope this pic is of use

[Brian]

Lever should be 1/2" from the top stop to set Draft Control (Qualitrol) and on the bottom stop to set Position Control.

Have you got the lift on its back? If so, you may be looking at the lever position upside down. The lever positions refer to the position when on the tractor.

I like the removal method for the flow control valve.

[4040t]

Thank you Brian

I have set it up as you describe above
It has a new piston seal and all valves etc are now functioning ok, I believe. Also new oil and a thourough clean out of the rear end.

This morning I tried it out and the position control side of it works perfectly which it didn't before (it was either up or down, nothing inbetween)

Now unfortunately the draught control side of it is either up or down! nothing inbetween

It only starts to lift the arms when the lever is about an inch from the stop, then it goes straight to the top

I will try it tomorrow with some weight on the arms, but I don't think it will make any difference

Any help/ideas would be appreciated
Thanks
Adrian

[4040t]

Having had another play, I seems the draught control does function to a point, but it is restricted to the top 1/4 of the lever quadrant
ie you can make it go to the top or bottom or midway within this restricted area
When putting a lever against the top link part, the arms will lift, but will not return to the point they were in before, just stay at the higher point

[Brian]

Draft control has no neutral it is either lifting or lowering and it only starts to lift when the lever is 1/2" from the top stop. As soon as you move away from that point the lift will drop.

The lever is only setting the amount of force that is required by the pressure on the top link from an implement, before the lift reacts, in the rest of the quadrant.

Just slightly down from the 1/2" setting of the lever a push of a few pounds on the top link will cause the lift arms to rise whilst if the lever is set halfway down the quadrant the force required on the top link will be very high indeed.

Your lift is working as it was designed to do.

[4040t]

Thanks ever so much Brian
I was about to take it apart again in the morning!

The trouble is, I have no idea what it should be like, but thanks to yourself taking the time to help, we can all learn a lot on here

[4040t]

It would seem I was a little premature to hope all would be ok!

Although the links go up and down ok, I still drops and corrects itself, once a second when at the very top, less when further down the quadrant. This was when the plough was attatched

Out of interest I lifted the front of an old diesel roller I have (which must be best part of a ton) It did the same thing, but when left suspended for a while it got less and less until it more or less stopped doing it

Strangely, if you put the links/plough right up as far as It will go, then disengage the pto, it stops dropping and correcting and just stays up in one place, so this must rule out the main seal (which is new) and also the safety valve at the end of the cylinder I guess

Help!!!

[Brian]

Once again you are reasonably OK. When the lift gets to the top the piston moves outside the ram cylinder and strikes a rod on the control valve link. This moves the valve into "neutral" and stops the lift lifting.

If it nudges the control valve lever a bit too far, it moves the valve into "lower" which causes the lift to drop, this moves the piston away from the control valve lever which allows the lift to raise again. That is where your cycling is coming from.

As you say, after a period it will slow down. Once you stop the engine and the lift does not go into the "raise" cycle, the lift holds up.

The lift was never meant to hold up for any length of time. It may correct up to once every two seconds without any cause for concern. Corrections can also be caused by the weight of an implement hanging too far back and pulling on the top link.

The weight of a sprayer with a full tank (100 gallons) of water can do this. Remember, pressure on the top link causes the lift to raise, tension on the top link causes the lift to lower. On a New Performance Super, increase the tension on the top link beyond the amount that causes it to lower and the lift will raise.

This is why, for your own safety, you never hitch up to an implement with the lift in Draft control. Any pressure or tension on the top link as you fit it can cause you to put the lift into raise or lower and you can be trapped. Did it once myself and had to go home and change my underwear! I was lucky!

The lift is designed to cycle, it is normal.

[4040t]

Brian, thank you for the explanation of what is happening

I remember seeing the pin you describe and can see how it would have the effect you describe (is it possible to alter an adjustment to help this stop happening?)

But what about when it's only half way up on the lift? Admitidly it is not so bad when in a lower position, but it seems to suggest oil must be leaking past somewhere.
I was just wondering what could pass oil when the pto is running, but stop passing it when turned off

It is making the tractor bounce up and down on the front which is a bit disconcerting!!!

Once again, thanks for your help
Adrian

[Brian]

Have you set the Draft Control Spring on the outside where the top link fits? There should be no free play in the yoke. If you find free play take the pin out and turn the yoke until there is none or possibly just a little. Your problem is in the control valve movement, there is no leak as such if the lift will hold and there is no leak from the valve so it is linkage that is giving you the problem.

Too much free play on the draft control yoke will give you that.

[4040t]

Thank you Brian
I have checked the top link fixing as you suggest, there was very little play, but I gave it a turn and there is no play now
This hasn't made any difference though

I have taken a few short videos at different settings

The first is when at the top stop
http://img841.imageshack.us/img841/4502/49bm.mp4

The second is mid position
http://img831.imageshack.us/img831/628/jlwi.mp4

The third is between mid/top position
http://img692.imageshack.us/img692/1051/r52l.mp4

The fourth is top position, then stopping the engine. It does drop a little at first but then stops and stays there
http://img84.imageshack.us/img84/592/urte.mp4

A friend has a SM, a little later (1963) than this one (1961) and his does not do this at all

I don't mind stripping it down again, I just want to make it better than it is at the moment

[Brian]

Pictures paint a thousand words!

To me that looks like either a control valve fault or a linkage fault. What happens when you pull the ASC knob out? Does the lift stop correcting and stay up?

The plough you have is not a heavy load for that lift, they were designed for a TS82 which is far heavier than the EP that you have.

Another thing to try to confirm where the problem is, Put a second pin in the third link rocker so that the rocker is fixed. Then repeat your test and see what happens.

[4040t]

Thanks Brian
I didn't pull out the ASC knob, The outlet is blanked off and the last time I pulled it out the hydraulic relief valve could be heard working. I will try it next time

I notice Agriline do a new control valve and bush, I might get one ordered. This tractor ran with a loader for a lot of it's life so the valve could be worn. I didn't think it seemed to bad, but then again, I have never seen/felt a new one!
I just presumed that if it was too slack in the bore, it would also pass oil when the tractor was turned off and the arms would drop?

I think there is to much play in the holes to make it worth while putting a second pin in, but I did watch the top link casting while it was running and there was no noticable movement to it

I did also try it an a high tickover, it was the same realy, just seemed to raise/drop quicker!

[Brian]

The replacement control valve is not a route I would go until it is certain that it is the problem. They are notoriously difficult to fit and get right. The valve and bush might be right when they are out of the cylinder but the dimensions change as you fit the bush and the control valve will then stick. Originally each control valve and bush were colour coded, after fitting a new bush you then had to go through all the colours to find a valve that would fit.

If the PR Valve continues to blow after you have pulled the ASC out, it would seem to indicate the lift is leaking down with the control valve and linkage no longer in the circuit. This does not seem to be the case from your Video.

Did you follow the setting procedure correctly when setting the lift up?

It is one of those things that is possibly so simple when you can see and touch the lift.

[4040t]

Brian
Thankfully it stopped raining long enough to take another video of it.
What happens when playing with the ASC valve is that the links stop dropping and correcting once you pull it out.
You can move the quadrant lever up and down and it no longer has any effect.

Sometimes once the ASC valve is pulled out it is nice and quiet, other times it sounds as though it’s in some sort of bypass mode as the engine clearly goes under load (like it’s pumping harder)

As you can see in the video I had to mess around with it to get it to do it when I was filming, you will also see that by just rotating the valve, it made it go under load again.
Once again, it’s probably easier to just watch it!

http://imageshack.us/clip/my-videos/853/kjjm.mp4/

[Brian]

1. In your test you are not in "Draft Control", your selector lever is in "Position Control". I have just checked back to your earlier pictures and can just see the selector in Position control in that too.

2. When you pull out the ASC you are diverting oil to a blanked off port so it will be normal to hear the PR Valve blow off. In the fully raised position, the knock off pin will move the linkage to neutral and the pressure will be diverted to dump. If the lift drops it will move the linkage/control valve to try and correct the drop but, with the ASC diverting the oil away from the ram cylinder, all it will do is "dead head". This is why you hear the PRV work sometimes and not others.

In Position control, when this happens, you loose control of the lift. If you have a trailer on the tipping pipe or anything else on the ASC controlled by the quadrant lever, it will continue to raise with the lever at the bottom of the quadrant.

3. Your turning of the AS Valve and changing the noise might possibly be the answer to the problem, you said she had been fitted with a loader. It is possible the AS Valve might be worn and it is here where your leak is. Any chance of getting another to try on?

[4040t]

Brian,
Just to clarify, the problem happens in position control and draft control
I just had a look at the drawings in the manual and it shows an o ring on the valve, perhaps this is worn/damaged, though I think it just stops oil leaking out externaly.
To be honest this is the only valve I didn't take out as I just presumed that with the outlet blocked off, It couldn't make any difference.
I will try to strip it out tomorrow and see whats what. Unfortunately I don't think I can borrow another one, but I could make a new one if I have to.
Looking at the schematic diagram it would appear to show either the oil goes to the cylinder or the APC outlet, or possibly leak externally (which it isn't) but drawings do not always show it as it is!
Clearly rotating the valve is having some influence on something!

To add to your previous question, I set the linkage up as per the manual, which has slightly different figures (.342" draft) and (.432 position) to the wiki method. I presume this is because of the slight difference in the lift arm setting height. I have a slip guage set, so it seemed the easiest way to do it.

Thanks again
Adrian

[4040t]

The one thing I have noticed is that mine does not have the gasket/shim type thing that goes between the control valve casting and top casting that is show in the agriline list
It does have o rings though, but I had better check to make sure it can't bypass out side of the o rings, there was some sort of slot type area if I remember correctly

[4040t]

Brian,
This afternoon I took the valve casting off and stripped apart the valve.
It all looks ok and seens to be a good fit, but I thought I had better try and put some pressure in it with the grease gun to check.
I filled the cavity with oil first before blanking it off


Without doubt a little oil is passing the end of the valve, more so if you rotate the valve
It passes with the valve in or out. I don't know how much pressure the grease gun is putting in there but I imagine it is not anywhere near as much as when the plough is on the back?
Theses pictures show where the oil ends up going. It ends up straight back in the area above the cylinder.





But, in the video when I pulled the valve out the arms stopped dropping once there was no oil feed to the cylinder, so I would guess that the oil that is passing this valve is not realy enough to make a noticable drop in the arms.

I did wonder about temporarily blocking the hole to proove if this small leak is having any effect, but I presume this hole may pass oil back from the flow valve as well?, as the hole goes at right angles through the casting.

I'm also trying to figure out why, in the last video, it didn't always make the pressure relief valve work until I turned the valve. I would be suprised if it could pass that much oil.
I could do with one of those endoscopes to look inside when it's running!