Agrokid lift lever stiff/stuck

[SteveDy]

Hi. This is SteveDy writing from France.
I have an Agrokid with a problem that no one can diagnose.
From new, the lift lever was stiff.
Soon after, it got even stiffer once the hydraulics had warmed up before jamming completely. It comes good briefly when cold, then sticks again.
The power steering works perfectly as does the three-point hitch using the draft control level. The fluid clogging indicator has never shown any sign of trouble with the fluid and the fluid level is normal. Several people have examined the visible portions of the linkage but can see no obvious problem.
I have asked several mechanics for a diagnosis but none has said anything reasonable other than suggesting that they disassembly the entire hydraulics block to see if they can find anything.
I would like to have a diagnosis or an inkling of a diagnosis before giving anyone the go-ahead.
Has anyone out there got any ideas.

 

[CalG]

My Hurlimman 435 control levers can be very difficult to move. But it's not related to the hydraulic system.

It's the plastic bushings /pivotblocks to which the handles are mounted. The plastic seems to collect dirt and grit.
I try to wash the pivots regularly with water pressure from the garden hose. It seems to help somewhat. At least for a short while.

The hydraulics in this one work fine, It's getting the control linkages to move with sensitivity that is the issue.
Your issue may be different. This Prince is an earlier model. (Fuel tank in front of the engine).

Simple enough to disconnect the linkage for the two lever arms right at the control valve in back of the tractor. then push and pull on those arms to test for operation.
Try with tractor running and also engine off.

 

[Leejohn]

You aren't over looking a friction adjustment are you?

 

[CalG]

I just spent a few moments with the service literature (Do you have a copy?)
If the trouble is not with the external actuator links, all the remaining pieces are under the lift top cover. There is a fussy bit of linkage there, But you will need to strip off the operator's station to get there.

Leejohn, The SDF Agrokid makes use of stops, but there are no adjustable friction elements. That would be a good place to look though. I am confused about the "differences" reported when first started and warmed up. That just makes no sense to me yet.

Photos of the 435 while fitting some additional hydraulic controls.
http://www.tractorbynet.com/forums/hydraulics/289138-hurlimann-loader-valve.html?highlight=Hurlimann

It works perfectly!.

 

[SteveDy]

My Hurlimman 435 control levers can be very difficult to move. But it's not related to the hydraulic system.

It's the plastic bushings /pivotblocks to which the handles are mounted. The plastic seems to collect dirt and grit.
I try to wash the pivots regularly with water pressure from the garden hose. It seems to help somewhat. At least for a short while.

The hydraulics in this one work fine, It's getting the control linkages to move with sensitivity that is the issue.
Your issue may be different. This Prince is an earlier model. (Fuel tank in front of the engine).

Simple enough to disconnect the linkage for the two lever arms right at the control valve in back of the tractor. then push and pull on those arms to test for operation.
Try with tractor running and also engine off.

Many thanks CalG. I've seen other Hurlimmans: they look like rebadged tractors from the same assembly line.
I will follow your advice as it sounds spot on.

 

[SteveDy]

Thanks for this too CalG.
Yes, the difference between cold and hot still baffles me too.
On the other hand, the steady increase in stiffness and ever-earlier sticking tight sure sound like a friction-on-plastic problem to me.
I will investigate further and report back at a later date.

Also, the service manual supplied in France is a dreadful translation from some original probably in Italian and generally poor.

 

[SteveDy]

Leejohn,

Thanks for your thoughts. My old Deutz 4006 had friction adjustments, but I don't think the Agrokid has them. Certainly not visible ones, anyway.

And while I'm here, thanks to TractorByNet. My post here has produced more useful information more quickly than a dozen attempts to get anything useful out of Deutz-Fahr in France.

 

[SteveDy]

After more research I can confirm that the problem is definitely correction in the linkages under the platform. My mechanic will tackle the job shortly. The aim is first to remove the corrosion, get the linkage working properly then install some system to facilitate regular lubrication. My tractor often lies idle for 2-3 months and apparently the problem is fairly common with all versions of this tractor that are left idle for too long or too often. To facilitate lubrication, I plan either to install a tube and simply drip oil onto the mechanism from time to time, or, alternatively, make a hole (and a cover for it) in the mudguard so that I can squirt in oil or WD40 as and when necessary. I'll report back here when the job is done.

 

[SteveDy]

Problem solved. It was corrosion of the bushings or friction pads or whatever they are called at the base of the control lever. (Occurs because my tractor often sits for weeks at a time without use. The problem is unlikely to arise with tractors in daily use.) Had to remove body to gain access. Cleaned and lubricated the bushing things, then cut a hole in the vertical panel forming the inner wall of the wheel space, the hole being positioned so that the bushing things could be lubricated without removing the body. Made a fitted a cover for said hole held in place by a pair of screws. (This might serve as the basis for a design change notice!)

 

[CalG]

Ahh!

Rust never sleeps!

I'm very happy to hear that the solution was simple. Though removing the operator's station is not trivial!

I used "Sil-glide" lubricant on the assembly. So far, so good. But It won't remain lubricated forever. Your solution to make a service door sounds like the right idea.

Please, don't use WD-40 ;-) Nothing but stoddard solvent with a little varnish added.