5211 hydraulics weak when hot

[mjrchode]

Hello,

I tried to use the search function but it was acting weird so I apologize if this subject has been covered before.

I have an old 5211 that we use on our small farm. It does everything we need and then some. This summer when cutting hay we noticed the hydraulics were slowing down after a long day in the field. To raise my JD1219 mower conditioner I would have to mash the accelerator almost to full speed to get the lift cylinder to raise the JD1219 moco.

When the tractor is cool the hydraulics work fine. Even now that it has cooled off (mid 80's here in TX) the hydraulic performance drops off rapidly when everything warms up. Starting to affect the loader as well.

No leaks on the tractor, loader or implements. Fluid changed at the beginning of every year. I did replace the fine mesh screen in the pump housing/plate at the beginning of this year as well as the large hydraulic filter. Is it just time to replace the hydraulic pump and pressure regulator?

Regards,
Shane
Trenton, TX

 

[Renze]

yes, sounds like you need a fresh pump.

 

[hve]

Fluid changed at the beginning of every year.

What oil did you use?
not sure about the 5211, but on the 7 series the specified oil is actually 80W90 Gearbox oil, this is a little thicker than universal tractor fluid, so changing to a thinner oil with an already tired pump would make it worse in a warm climate (ie not freezing).

Is the oil getting excessively hot? ... it top of gearbox getting too hot to touch?
if so, check external hydraulic circuit is not tied back and bypassing the relief valve

 

[mjrchode]

Hello Steve,

The manual calls for 80w90 OR standard tractor transmission fluid. I've been using the tractor transmission fluid for the last few years. no issue until this summer.

The transmission does get hot when we have been working hard for several hrs. The only aftermarket add on is the Great Bend loader that is tied into the remote connections on the back of the tractor. The loader was on the tractor when we bought it. I was considering connecting the loader directly to the pump via the hydraulic pump plate but I don't understand the BYD (power beyond) connections. Would be nice to have my remotes free all the time though.

Guess I'll try a new pump and regulator this winter. more projects.

Regards,
Shane

 

[Renze]

Guess I'll try a new pump and regulator this winter. more projects.

If you park it downhill, into a ditch or something, you can swap the pump without draining off the oil. With scraping the old gaskets off etcetera, its less than an hour of work.

 

[askinner]

Just to add to Renze's great tip, engage the pto clutch once you have the new pump in, and don't disengage it until the tractor is level again. Saves running the new pump dry

 

[hve]

Just to add to Renze's great tip, engage the pto clutch once you have the new pump in, and don't disengage it until the tractor is level again. Saves running the new pump dry

I think you mean, "Disengage" the PTO Clutch? (clutch lever "up" on the UR1 series, not sure on a 5211)
ie. so the pump and pto are not engaged.

Also pre-fill the pump with clean oil before fitting

 

[askinner]

Just to add to Renze's great tip, engage the pto clutch once you have the new pump in, and don't disengage it until the tractor is level again. Saves running the new pump dry

I think you mean, "Disengage" the PTO Clutch? (clutch lever "up" on the UR1 series, not sure on a 5211)
ie. so the pump and pto are not engaged.

Also pre-fill the pump with clean oil before fitting

Yes! Sorry, I got that the wrong way around!! And good tip about filling with oil too, I use grease, it has the same effect, but just stays in there better.

 

[hve]

[And good tip about filling with oil too, I use grease, it has the same effect, but just stays in there better.

I use Chain-bar-lube, (or Moreys) as it will cling to the surface and prevent scuffing, ..... you have to be a bit careful using grease as some grease has additives and thickener systems (soaps and fillers, etc) that will damage hydraulic systems and block up filters i have heard Petroleum Jelly (aka Vaseline) is better than grease for this reason.