hydraulics

[peter]

This question concerns the Ford Dexta from 1963. I can only raise the lift arms as well as in position control as in qualitrol when I put the main control lever well behind the fixed point. The range to lift is very short and when I have a load in the lift arms the lift arms are slowly going down. Apperantly the hydraulics are in auxilary service. How do I change it back to control the lift arms? If I pull the auxiliary service knob the lift arms do not react at all, but I hear the pump working. Everything seems normal. It seems I can only change when the lift arms are fully raised and the control valve is in neutral. However no reaction. How to change to lift arms control?

[Brian]

Think you have been given wrong information. If you were in Auxiliary Service then the lift arms would not work at all.

You most likely have a worn Position Control follower pin and the linkage needs resetting as well so you will have to take the lift off.

It would be advisable to fit a new piston seal and "O" rings whilst you are in there. Make sure you get the lipped piston seal and not the "O" ring and backing washer which are for the "X" and "Y" series tractors.

Go to the Wiki from the home page (fordsontractorpages and dotty are the passwords) and there is an article on setting up the lift without the special tools.

[peter]

Hello Brian, thank you for your information. Piston seal might be a problem, however when the auxillary knob is pulled out, the lift arms do not react. When the knob is pushed in the control lever must go beyond the fixed point in order to fully raise the lift arms. In the article www.fordson-dexta.de (page 5 hydraulics) they say that it is important that the main control lever is in a neutral position before changing from lift arm to auxillary service operation or vice versa. You can do it when the lift arms are fully raised and the control valve is in a neutral position. I tried it but no change. How can I find the neutral position of the contrl valve?

[Brian]

It does not matter where the main control lever is, you can select either Position Control or Draft Control.

The lift lever and arms should be either lowered or fully raised before either is selected.

The reason is safety, not a problem with the selection. If for example, the lift lever was in the mid quadrant position and the implement on the arms raised to a half way position with Position Control selected, if you then changed to Draft Control, the implement would immediately lower as, the quadrant lever has to be within 13 mm of the top stop to raise in Draft Control. As the implement will fall very quickly, it could damage it or anyone near it.

As I said in my post, you have an adjustment problem if you need to move the lever beyond the top stop to get the lift to raise in either Position Control or Draft Control. In Position Control, the lift should start to raise within 13 mm of the bottom stop in the quadrant approx. moving a little as you move the quadrant lever, and in Draft Control it should be within 13 mm of the top stop and the lift should raise fully.

When you change to Auxiliary Service, all you are doing is diverting oil, However it is easier to move the control when oil is not being pumped and the system under load so again the main control lever should be in the fully lowered or neutral position. Auxiliary Service should only be used in Draft Control and so neutral will be around 13 mm from the top stop.

Because of the cut-off pin internally on the linkage, if the arms are fully raised when you need to use Auxiliary Services, you may need to move the control lever beyond the top stop. To avoid this, the lift arms should be within 13mm of being fully raised when you change to Auxiliary Services.

[peter]

Thank you for your reply. I will try it.

[niallsdexta]

Hi Brian,

Quick question for you on the piston seal, you say to make sure you get the lipped piston seal and not the 'O' ring and backing plate, why is this?

Also i replaced my piston seal which was a lipped seal but still had to place the backing plate to reduce the amount of rectifing the arms were doing loaded or unloaded! annoying thing is they Still do it!!

I have reset the settings many times no difference, what could be causing thsi to still happen or is it crazy but normal.

Cheers,
Niall.

[Brian]

Niall,

There is no backing washer with the lipped seal which was used on the Dexta. Replacement kits seem to send out the "O" ring and backing washer that was used in the later 2/3000 tractors, these will not fit on the Dexta piston, however if a 2/3000 piston is used then they will be OK.

Constant lift correction indicates a leak. You have to identify the area that is leaking. By pulling out the auxiliary service knob with the lift arms raised you isolated areas of possible leakage. If the lift remains raised when the knob is pulled out, your leak is in the control valve/unload valve plug/check valve area or even in the "O" rings under the Auxiliary Service plate, possibly the spool in the plate itself.

If the lift still drops the leak is piston seal/ram cylinder safety valve/ram cylinder "O" rings/cracked or scored ram cylinder.

[niallsdexta]

Thanks Brian,

Really appreciate your help, i will check these tonight and see if i can see something.

[peter]

Hello Brian,
last summer you indicated me to get into the hydraulics system, so I did. Apperantly the main spring and so the draft control spring were stuck by mud and rust in the upper housing. So I cleaned everything and put new O rings etc. Is it possible that the control valve in my dexta has no O ring? I checked but did not see an O ring.
My main question is how to set draft control and position control. I understand how to do according the inform Dexta and Super Major Hydraulic Setting. However in order to begin you have to put the lift arms in a certain position. *Now move the arms down until the upper? surface of the yoke in which the linkage fits is level with the gasket surface of the lift housing". This is impossible because of the piston and cilinderhousing. I can not lower the lift arms enough. Should it be the under surface of the yoke? In this case the piston is almost down.

Thank you, Peter de Graag

My dexta has the number 957 E 7005

[Brian]

The arms must be as far down as you can get them, the piston should be in the fully lowered position.

[peter]

Thank you Brian for all your help

Peter

[Phil C]

Hi All
Can anybody tell me if the stop pin on the position control linage should have a grove cut in it were it rubs on the ram arm linkage (its a it like a cam on the side of the ram arm linkage). Mine has a grove in the stop where it hits the ram arm linkage cam, the grove is about half way though the stop pin, not sure if it should be like this or if it is worn.
Cheers Phil

[Bensdexta]

Hi All
Can anybody tell me if the stop pin on the position control linage should have a grove cut in it were it rubs on the ram arm linkage (its a it like a cam on the side of the ram arm linkage). Mine has a grove in the stop where it hits the ram arm linkage cam, the grove is about half way though the stop pin, not sure if it should be like this or if it is worn.

If you mean like Dextrous' pin shown here? Ans: No!!

Search on here for how to replace this pin.

[Phil C]

Thanks Bensdexta
thats the one, worn the same as the picture. I've found a high tenstile bolt of the same diameter as the dexterous pin cut and formed the same and pressed in.
I've been rebuilding a 1962 Super Dexta almost got the power train together now ready for a respray, I'll put same pictures up soon so you can all have a look.
Thanks again
Phil

[Bensdexta]

Think you have been given wrong information. If you were in Auxiliary Service then the lift arms would not work at all.
You most likely have a worn Position Control follower pin and the linkage needs resetting as well so you will have to take the lift off.
It would be advisable to fit a new piston seal and "O" rings whilst you are in there. Make sure you get the lipped piston seal and not the "O" ring and backing washer which are for the "X" and "Y" series tractors.
Go to the Wiki from the home page (fordsontractorpages and dotty are the passwords) and there is an article on setting up the lift without the special tools.

Good work.
I expect you've seen Brian post ^ as now's your chance to set everything up perfectly!