Hydraulics dead on start-up... sometimes

[AlbionWood]

Hello geniuses! I have an intermittent problem with the hydraulics on my Ford 1920. If I start the tractor and immediately operate any of the hydraulics, often they will immediately and completely stop working. Say, if I start the engine while the 3ph lever is up, the hitch will jump a bit and then stop, and all the hydraulics are totally dead, no response from any valves (3-pt, FEL, aux toplink). Sometimes when this happens I can rev the engine to full throttle for a while, and get the hydraulics back; or, I can wedge something under the bucket and drive forward, putting back pressure on the FEL cylinders, and suddenly the hydraulics will "jump" and begin working again. Often when that happens, they will be jerky for a bit, but eventually will work better.

Used to be, sometimes the hydraulics would get worse as I worked, stuttering and jerking until eventually they would stop altogether. Drained and replaced oil and hydraulic filter, and that problem mostly went away. When I changed the filter there was rusty scale partly clogging the inlet holes. (That can't be good.)

I think this problem is worse when I run the PTO, rototilling or mowing for example.

Any ideas what is causing this, and how I fix it?

 

[J_J]

Install a hyd gage in the system and do some logical trouble shooting. Install the gage before the first valve.

 

[Jbrink64]

Sounds like air is getting into the suction side of the system. Make sure you have the correct filter, I think there are 2 kinds depending on the year. Check the o-rings on the pipes at the filter housing, the short rubber hose and clamps at the pump, and any damage to the suction pipe.

 

[wdchyd]

Make sure you check the suction hose (take it off and look inside), sometimes these get replaced with the wrong type and the inner liner collapses....the other thing to check out is the coupler/spline on your pump, this is common when everything goes dead....

I know I'll get beat up by saying this, but here's what I'd do...
When something like this happens I always go out of my way to install flow meter to see rule out oil delivery problem......it'll show if the problem is upstream or downstream of flow meter......

 

[J_J]

wdchyd

I agree with you. Theoretical trouble shooting is good if one knows how to use the data, but a test rig to show results, makes it even better.

 

[Leejohn]

(When I changed the filter there was rusty scale partly clogging the inlet holes.)


Did you check and see if you tractor has a intake screen and clean?

 

[beenthere]

Have you checked the hyd. fluid level? Seems your pump is losing its prime. Agree with the other trouble shooting ideas as well.

 

[AlbionWood]

OK, I have some work to do then... assuming I solve the electrical problem and get the **** thing started again... Thanks everybody.