My F-1700 testing my patience

stevewatr · Saturday at 10:07 AM

Rather than start a new thread, I figure I'd try and revive this one with my problem.

My Ford 1920 (Shabura) tractor 3 point hydraulic lift has a ghost in the machine.

When it works, it has no problem lifting a heavy brush hog, and I do not have any issues with jerky lifting, or sudden dropping. The knob in front of the seat that controls rate of fall work perfectly.

Several times now I have encountered a strange issue where the lift 100% stops working. This never happens when working the tractor, only with initial start up.

A couple times I found revving the engine "woke up the hydraulics".

I'm not positive, but I think cold weather is a common factor when this occurs.

And when I say it doesn't work, I mean nada, zilch, zip. lift lever moves easily and has no effect. And since it is at startup, the impliment is on the ground, so there is no weight on the arms (I always lower the impliment when done for the day)

Well the intermittant issue has apparently decided to stay broken.

Fluid level is good, no strange noises as far as I can tell over the diesel noise.

Could a failing cylinder seal start off with intermittant failure like this? Or would a sticking relief valve be more likely?

JC-jetro · Sunday at 9:51 AM

The cylinder head for he lift system has a main bypass back to the difffy. This thing has a stiff pressure and a ball check valve. That would work the same as relief pressure device on the pump discharge circuit before fluid is routed to lift spool on it's way to lift piston head. Those two areas can be suspect. Need to verify also when the system does not work if you have flow passed the spool. I had a ton of pics with this thread that was hosted on a another site rather here and it was lost due to not renewing the subscription. On the right hand of list cylinder head from driver position there is a cap that if you open can verify if the pump is actually working or not. I ended up overhauling my hyd pump that I am sure you can find info about it here at this Site.

JC

stevewatr · 2025-11-04T04:12:44-0500

JC-jetro said:
The cylinder head for he lift system has a main bypass back to the difffy. This thing has a stiff pressure and a ball check valve. That would work the same as relief pressure device on the pump discharge circuit before fluid is routed to lift spool on it's way to lift piston head. Those two areas can be suspect. Need to verify also when the system does not work if you have flow passed the spool. I had a ton of pics with this thread that was hosted on a another site rather here and it was lost due to not renewing the subscription. On the right hand of list cylinder head from driver position there is a cap that if you open can verify if the pump is actually working or not. I ended up overhauling my hyd pump that I am sure you can find info about it here at this Site.

JC

Thanks for getting back to me. I was wondering why all those photos did not load, too bad they were lost. I was already thinking my pump is probably okay, just based on the intermitant nature of the failure. My experience with hydraulic pumps is that they loose pressure over time as they wear, or have a catostrophic event they don't come back from.

Is the cap you mention under the seat mount? There is the fill cap to add fluid located at the rear between the lift arms, and a small cap with dipstick attached on the floor up towards the dash/cowl.

But it sounds like you mean something else?

JC-jetro · 2025-11-04T12:03:31-0500

stevewatr said:
Thanks for getting back to me. I was wondering why all those photos did not load, too bad they were lost. I was already thinking my pump is probably okay, just based on the intermitant nature of the failure. My experience with hydraulic pumps is that they loose pressure over time as they wear, or have a catostrophic event they don't come back from.

Is the cap you mention under the seat mount? There is the fill cap to add fluid located at the rear between the lift arms, and a small cap with dipstick attached on the floor up towards the dash/cowl.

But it sounds like you mean something else?

Howdy,
On the pump thing, if you run a positive displacement pump like a gear type dry then excess heat will destroy and wear the gears same as running an engine with no oil, however pump seal might be bad, worn out or destroyed where the pump will churn but no flow. That pump can be saved by a simple overhaul. I think I have those on this site and the pics did not get wiped out.

Pics below show the lift piston head on 1700. Please verify if yours is the same, I think all 1000 series use the same design. The one withe gauge is flow and pressure after the spool and the one on the opposite is over pressure relief to save the lift piston seal. Let's say you have something heavy hanging on 3 point and you are driving a rough terrain, if you hit the bump , that kinetic energy experienced by the lift arms will be added to the system pressure due to mechanical linkage between 3 point and lift arm. That would be an instantaneous over pressure that would be directed to diffy for safety saving the lift piston seal. If for whatever reason that check valve is not holding then flow would be diverted to diffy rather lift. That might be the issue. it will be a monumental task for me to go through entire thread and re-post all the pertinent pics. I hope that helped some.