1961 Dexta Hydraulics

This forum is about the Fordson Dexta, Super Dexta and Petrol Dexta.
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bigmakatak
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1961 Dexta Hydraulics

Post by bigmakatak »

Hello,

So after reading about old tractors on the internet for a while, I caught the bug and recently purchased a 1961 Dexta (made between January and October) that runs very well and will try to restore more fully. Actually used one just like it in my earlier years.

The first issue is that the 3 point lift arms only raise about 6" or so with the draft control lever horizontal. Pointed down to the floor board I get no movement up or down. It has hydraulic oil. Have not had it apart yet to check anything else like filters, linkages and so on.

I have read in a few places that it may be an internal worn steel dowel that is attached to a power lift valve control lever. Some places call it a "cam follower" . It is apparently 3/8'" dia. x 1-3/4" long and is available through Ford/New Holland. Needs to be pressed in too I guess. I have also seen it described as 5/16" dia by 7/8" long too in some places so I will not no for sure until I see it.

So I am going to start there I believe and pull the hydraulic chamber top off but before I do that I am looking for advice with regard to:

1. Are there some more easy diagnostics I should do before taking it apart or other things to check?
2. As long as I am going to open it up, are there any other parts that I will automatically (or most likely) need to replace besides the gasket? Like "o" rings, small valves and so on.

Thanks for any assistance/advice possible. If there is a post that already covers all of this please direct me to it. The tractor is 100 miles form where I live so I have to be efficient when I head over there to work on it. I am not a good mechanic (obviously) but can get some help if I need it.

Bigmakatak

Brian
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Re: 1961 Dexta Hydraulics

Post by Brian »

Welcome to the board.

You may find the best way to work will be to get the lift off and bring it back to your base to work on. If it has not been off for a while pins may be seized and getting it off could use up a fair bit of time.

The lift itself could also require a bit of freeing off in the linkage, I have had to make use of bags of heat and whacking to strip down some units but they have been around 50 + years so are stuck in their ways. (like me). :D

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From what you say it does sound as if the cam follower pin is worn or missing. Your symptoms are exactly what I would expect. You may find that, with the draft/position selector pointing down and the quadrant lever about 1" from the top, if you push the draft/position selector back towards the axle, the lift arms will raise. This would again indicate a worn pin.

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This is the pin in question, carefully remove and replace it as you can bend the likage and give yourself other problems down the line.

Another area to check whilst you have the top off is the piston seal, control valve and unload valve.

Piston seal should be a lipped seal not the "O" ring and leather washer supplied by some after market suppliers, that is for the later Ford Dexta 3000. If you fit the later piston it will work but sometimes a local seal supplier can make a piston seal. I had my Major one made for £11.00.

The control valve should be free in the bushing, not bent or scored and should drop through the bushing under its own weight.

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Remove the plug from the unload valve by drawing it out as shown.

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Under no circumstances drive it out from the rear using a punch. A punch may be used to push the valve out once the plug is out of the way.

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The unload valve may have an "O" ring as shown or a metal piston ring, it could even have nothing at all. All the above can be correct! :clap:

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Be careful not to break the metal ring if fitted. I use grease and a feeler gauge to work it in when I replace it.

If you have an "O" ring fitted I would be tempted NOT to replace it with one supplied by any supplier other than Case New Holland. The material used in manufacture is special to that ring and does not deform or swell under heat, other suppliers rings do and the lift will stick in operation. I have had this problem many times over the years and until Fords found the right mix, the lifts became a serious problem back in the day. The official cure was to remove the ring and throw it away, the lift will then work quite happily.

The unload valve is a "shuttle" valve and is controlled by the back pressure in the system created by the valve in the bottom of the return filter. As this is only about 11 psi the valve must move freely in its bushing.

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The return filter is on the right, on the pipe. The pump intake filter is the canister on the left.

When you come to rebuilding and resetting a step by step guide with adjustments can be found here.

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

You will need the user name "fordsontractorpages" and the password "dotty" to get into it.
Fordson Tractor Pages, now officially linked to: Fordson Tractor Club of Australia, Ford and Fordson Association and Blue Force.
Brian

Bensdexta
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Location: N Wales

Re: 1961 Dexta Hydraulics

Post by Bensdexta »

Have you got a copy of the Hydraulics section of the Dexta Workshop manual?
Bensdexta - 1961 working for a living!

bigmakatak
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Re: 1961 Dexta Hydraulics

Post by bigmakatak »

Brian and Bendexta thanks for the fantastic replies! The pictures are going to be a great help.
I hope my 1961 looks that good once apart. I will read the step by step guide as suggested too.
Good advice for bringing the cap back with me to tinker with at home.

Ben.....Yes, I believe I have downloaded the hydraulics portion of the manual a while ago.

I really appreciate the assistance to get started off in the right direction. I am sure I will have more questions along the journey.

Bigmakatak

shawnee
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Re: 1961 Dexta Hydraulics

Post by shawnee »

5/16 x 7/8 on my 1961 dexta just replaced knocked it out with a punch with a pry bar behind it

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