How to bleed hydraulics on front end loader?

[MadJack]

My FEL is most times slow to respond, comes up about a foot, stalls, then goes up smooth at 1500+ rpms.
Letting the FEL down it responds well with initial stop but then creeps down 3 to 4 inches fairly quickly.

I'm suspecting air in the system is causing this. Can anyone explain where/what line to bleed air from the system?
Tractor is an '86 Ford 2110 (Jap model).

(A friend suspects air, and possibly a bad spool valve)

 

[kennyd]

Hydraulic systems are self-purging, there is no need to "bleed" the system.

 

[Doughknob]

Yeah, not sure that is the case. Self purging assuming all air bubbles can migrate to the reservoir. One my be stuck in a hose loop in the loader. I’d point the tractor & loader down the steepest hill i could find and cycle all the controls a while.

 

[ROUSTABOUT]

Never heard of such.

 

[npalen]

I'm wondering if your valve has no load checks installed and/or if you are letting it free-fall when lowering. Either one would tend to induce air. Try raising and then lowering slowly several time letting the pump keep up with the cylinders to see if this doesn't purge the air.

 

[kennyd]

Yeah, not sure that is the case. Self purging assuming all air bubbles can migrate to the reservoir. One my be stuck in a hose loop in the loader. I’d point the tractor & loader down the steepest hill i could find and cycle all the controls a while.

Air can get pushed past the seals whereas fluid cannot. Do you think dealers or the factory bleeds loaders when they install them?

 

[4570Man]

Hydraulic systems are self bleeding if you cycle it a few times. But it sounds like the pump may be sucking air. Have you checked the hydraulic oil level?

 

[M59]

MadJack,

The usual route for hydraulic fluid, under high pressure, out to the cylinder and then back to hydraulic reservoir via a low ( no pressure) pressure line where entrained air or vapor ( air bubbles or vaporized water if excessively contaminated fluid is in use and fluid is very hot) is separated out. The reservoir is vented to the outside by one way valve.

It would be highly unusual, unless you had a constant inflow of air past a seal, for air to be constantly in the hydraulic system.

Since the Ford 2110 FEL cyclinders are double acting ( you power up and power down ), I believe your issue is more hydraulic control related ( control valve, shuttle/spool valve, unknown restriction, damaged piston, ?? ) related and not air in the system.

 

[MadJack]

MadJack,

The usual route for hydraulic fluid, under high pressure, out to the cylinder and then back to hydraulic reservoir via a low ( no pressure) pressure line where entrained air or vapor ( air bubbles or vaporized water if excessively contaminated fluid is in use and fluid is very hot) is separated out. The reservoir is vented to the outside by one way valve.

It would be highly unusual, unless you had a constant inflow of air past a seal, for air to be constantly in the hydraulic system.

Since the Ford 2110 FEL cyclinders are double acting ( you power up and power down ), I believe your issue is more hydraulic control related ( control valve, shuttle/spool valve, unknown restriction, damaged piston, ?? ) related and not air in the system.

Thank you M59!
I did recently change all hydraulic fluid and replace it, and a new filter. Some improvement which allows/encourages me to run it more, but still not as good as other tractors I've owned before.

Good excuse to upgrade to a single stick, possibly 3 spool with electric 3rd... (possible grapple or just a forks-finger in the future)

 

[4570Man]

Thank you M59!
I did recently change all hydraulic fluid and replace it, and a new filter. Some improvement which allows/encourages me to run it more, but still not as good as other tractors I've owned before.

Good excuse to upgrade to a single stick, possibly 3 spool with electric 3rd... (possible grapple or just a forks-finger in the future)

Can you see the hydraulic fluid in the tank to see if it’s aerated or foamy after using it?