Dexta lift arms slightly dropping

[Cores]

Good day,

I have a '60 dexta and I may have a problem with the hydraulics system, but as I am pretty new to this I have no idea how to diagnose this properly...
Overall, the lift arms work just fine, they follow the movement of the quadrant lever nice and the response is fast. However with a certain load it seems that they slowly loose height, and then move up again. It takes around 20-25 seconds to drop half an inch, and then they are pumped up again.
I guess this isn't they way it should behave? I know there are some valves inside the hydraulic system, but I have no idea what could cause these symptoms?
Just for information: I recently changed the oil in the rear axle and what came out of it was a caramel colored mixture of oil and water (I think...). The axle is now filled with mineral 20W50 oil.
There's also a mild whining noise coming from the hydraulics pump. Is this ok or should it be absolutely "quiet"?

Any help is appreciated!

Thanks and Best regards

[scoobyjim]

sounds like the lift cylinder seal is passing. with the new thinner oil it will pass easier than the oil thicker oil. not az bad job, just remove the hydraulic top cover and replace the seal for a few pounds.

[tom lad]

hi
seal is easy to change , search on here , also see cam follower pin ,
best to aim to check everything while ur in there ,

biggest prob is the heavy lift cover .

tom.

[Cores]

Ok, I'm gonna get a set of new gaskets and seals to start with then...
About this cam follower pin, I've seen pictures where it was almost cut in half. What exactly are the symptoms when it's worn out?
thanks,

[Cores]

I've been playing around a bit with the lift arms, and it appears that they don't drop when I pull the aux switch. That would mean that the piston seal is ok, right? Could it be that the seals of the aux switch are leaking instead??
Thanks or your thoughts...

[tom lad]

yes i agree, the ram seal sounds ok

my sdeaxta does the same ,
i'm curantly blameing the flow responce spool , i think it worn and oil is leaking past it .

easy to remove the aux chest to explore it further , poss one of the oil ring on the sealing faces ??

either way if the internal seals r 50 + years old then there prob due for a service

hope this helps
also u can swap the auz chest to test that ?

[Brian]

The original problem is pretty normal for a Dexta, a correction rate of up to 8 times in a minute was acceptable when the tractor was new.