Qualitrol set up

[atkiman]

I had a problem with the hydraulics on my Super Major, the lift would only operate at the very top of the quadrant.
The control valve was set up using Brian's procedure and now the arms go to the position set by the quadrant (position control) and raise and lower when pushing the top link in qualitrol position.
Everything seemed fine until I was demonstrating to a friend, then discovered that in position control, when the arms are more than half way up, and the top link is pushed, the arms raise (this is in position control, not qualitrol). Is this normal?

I've removed the unit several times and tried different variations of set up, but whenever the quadrant lever is more than half way up, the qualitrol fork pushes on the control valve actuating lever when the top link is pushed.

[Brian]

What sort of Super is it? Nothing in the set up would cause interaction between Draft and Position control unless the linkage is bent or sticking. It is certainly not normal.

[Chug-A-Lug]

I have a similar problem with a Super Dexta. Very interested in the outcome of this thread...

[atkiman]

Hi Brian

It is an early Super, with single acting qualitrol.

Here is a picture with lever at the top of the quadrant, in position control, and the top link pushed in (large spring removed so it stays in)

The position rod adjuster and the spring are removed for clarity. As you can see, the turnbuckle is screwed all the way in but the qualitrol rod is still pushing on the control rod. I suspect as you said, that something is twisted or worn.

[Brian]

You need to have the Draft Control main spring and plunger fitted and correctly adjusted before the fork will move from the pin and the control lever must be 1/2" from the top stop, not the top of the quadrant. Lift arms must also be in the lowered position.

The linkage from the main spring should be loose with no main spring fitted so there should be no pressure at all on the linkage. Might be an idea to check where the linkage goes through the top cover. There should also be a locating peg coming down from one of the seat retaining studs.

Set it like that and take another picture of the linkage please.

[atkiman]

Hi Brian

I have re-assembled the unit and set it up.

The first two pictures show "qualitrol" set up.





These two show "position" set up





These two show top link pushed in in "position" you can see it is pivoting on the qualitrol rod instead of the position rod

[Brian]

Your last but one picture shows the Draft plunger on the back of the lift away from the back housing, it should be nearly resting on the rear of the top cover.






These pictures do not really show what we need but I think you can see that there is a lot more clearance on the linkage.

I would suspect there is something wrong with the Draft Yoke/spring set up. I wonder if the later spring and yoke have been fitted at some time.



Does your Draft Yoke housing look like this?

Have you screwed the Yoke right out and checked the big spring in there? You should be able to see the spring through the hole in the back as the lift lies on its back but yours looks as if the spring is missing.

You have the NP Pressure Relief Valve, this may have been added at a later date. Please check that you do not have a Drop Restrictor. If you do have one, someone has fitted a NP lift and the set up is different.

OK, I re-read your post and you have removed the large spring. This needs to be in place and under the correct pressure before the lift is set.

[atkiman]

Hi Brian

Sorry I confused thing a bit there. The set up was done with the yolk spring in place and adjusted, the spring was then removed to test the qualitrol easily without using a pry bar. In the picture with the draft plunger not resting on the back cover, the yolk spring is removed.

Here is a photo of the yolk, I think it is the same as the one in your photo.




Here is a photo taken from the same position as your second photo:



The position of the rotating cam below the fork looks to be a bit different, and the qualitrol fork is almost pushing on the control valve lever.

On your photo, what is pushing the control valve in? It looks like neither the position control rod or the qualitrol fork are pushing on the control valve lever.

Thanks for your help with this problem.

[Brian]

In my picture the lift is in Position control, the lever is at the bottom of the quadrant and the arms are fully raised. So the cam on the lift arms is pushing the valve forward. And there is a lot of clearance in the Draft fork.

When working in Draft control, the top link only moves the spring less than 2 mm so it is not as if the Draft Yoke is moving forward 20-30 mm.

I have seen the Position control and Draft control arms bent so the two touch, you may have a contact mark on the front of the Position Control assembly. As you say, your linkage looks very close together when compared with mine.

I am more and more convinced that you have a linkage fault but cannot quite see what it is. I am hoping to take my lift off again, this weekend, if the weather remains fair, so will get more pictures and study the real thing in depth.

[atkiman]

Thanks Brian

Good luck with your lift this weekend.

I am going to the Farming Yesteryear rally at Scone this weekend. Not taking the Major though, I will be taking my old lorry instead.