The Fordson Tractor Pages Forum

I'm having a problem with the hydraulics and hope you guys can help me.
About a month ago I changed the hydraulic lift cover for another one to make the rear lift working again on my narow Dexta.
Only to find out later on that the front lift lost power since then.
Changed the oil, about 12-13 litres came out and filled her up again with 20 litres of the right oil.
She does lift about 250 kilo's on the front still, but not the 500 I'm needed when driving hay around and before the swap it did lift it. (not with ease, but still did it)
I've got no leaks and can hear the pup working when using the front loader or rear lift.
Is it game over for the pump of can I rebuild it, or could it be something else?

Inspect the valves for internal leaks, which are not uncommon and set the pressure relief valve to 2500 psi.
Sandy

Checking the valves on the pump itself?
I did clean the pressure release valve, but where can I change the pressure on it?

Check the pump pressure using a pressure gauge, it should be at least 2000psi. If it's ok, check the seals on the auxiliary control valve, if they are ok remove the top cover and double check all the seals and o rings. Start with the simple things and work towards the expensive ones
John

The seals on the auxilary control and top cover are new and not leaking.
Could be that one or two O-rings are out of place, but with fluid seal and no leaks that looks okay to me?

Forgot to mention, the rear lift is working like it should and is strong as well. (lifts the back weight without any problem, but lifting the same weight standing on a pallet and with the front loader it can't lift it)

Sounds like the pump is ok as is the pressure relief valve. I have to admit i'm no expert on dextas, is it the auxiliary valve that diverts flow from back to front?

Sounds like an option.
That is in the handle you move around?

I'm no expert either zo happy with all reactions I get

Done a lot of work on the Dexta, but with a lot of information from the internet.

Sounds to me like there may be a problem with the valve that diverts oil from the back to the front. There is either a leak or it is not allowing enough oil through. Take it apart and check its not blocked and that all the seals are good. Did you replace the valve when you changed the top cover? If the valve hasnt been used for a while the o rings could well have hardened up and shrunk, allowing oil to leak past them

Where can I find it?
I didn't change it, before I got the Dexta they only used the hydraulics on the front and the weight on the back was always hanging on and couldn't get the rear working again until I changed the top cover because the whole mechanism was stuck.

Looked a bit further then my nose is.
Should I remove the hydraulics control that is under the seat?
And the valve is in there?

The front loader did lift 450/500 kilo's max before the trouble started.

I depends what setup you have on your tractor, is there a black knob in front of the seat to the right?

It has one indeed.
Will make a picture of it later today.

Try pulling it out and see if the loader works any better

This is the one.
Pushing it in makes the rear lift work, pulling it out starts the front. But only with the hight ajustment pulled up.

The pressure relief valve must read 2500 psi, look at the auxiliary spool as John says, there are o-rings there but there's also a lapped bore, when worn, an oversized spool was available from Ford (colour coded).
Sandy

Ordered this set:



Should be the right one? It is the only one they have for the Dexta.

Aah, Sandy has appeared. He will be able to tell you alot more about that valve than i can, if you ask him nicely he may even have a diagram of how it works and where the seals go
Cheers
John

If so I would be really happy

You seem to have ordered replacement plugs for auxiliary service valve block. Unfortunately they're for the later block with flow control. Keep the o-rings though, as they might do for other things. Here's the manual, it has a good section on this spool.
http://www.smallholderservices.co.uk/si ... hydraulics
Sandy

It was the only set they had, so had to gues it was the right one.
Not tot expensive so maybe we will keep in stock

Thanks for the document! It is very handy and gives a lot of information

Sandy is a mine of information if you get stuck, hope you get it all sorted. Shouldn't be too difficult, just takes a bit of time to go through everything but it doesnt sound like you have any major problems
John

Got the old girl back together.
Couldn't find the parts for the hydraulics block so replaced it with a new one.
Only thing I haven't tested yet is the strenght of the front loader, will test it this monday.

use draftcontrol when operating your front lift!

Remember qualitrol (draft control) is when the selector lever (just below the auxiliary service block on the RH side of the top cover) is down.
Sandy