My F-1700 testing my patience

JC-jetro · Mar 15, 2020

shannondurst said:
Relief valve pics of how I dissembled it View attachment 645596 View attachment 645597 View attachment 645598 View attachment 645599 View attachment 645600

I really can't see anything glaringly wrong.I have the same shape, stiffness (just eye baling)spring and the rest of what you have in the pics. The poppet is nice and conical. Zoomed in pretty good and can't see anything wrong. I noticed your adjustment is all the way in, increasing spring stiffness and hyd pressure. I would back it all the way out, as if all you have is spring and adjustment. Have a gauge there at the lift assembly head and turn the tractor on. See if it makes all the racket or not. I would gradually turn the screw in to increase the pressure. Stop right where it starts squealing and the turn it back a hair for it to stop. See if you can lift anything up with 3-point. At this point, I would care to see if i can lift my implement, say a brush hog without vibration and squealing. if it could do it @ 1100 psi then I leave the adjustment be. if raising and lowering does not contribute to dead heading of the pump then I think your spool must be ok. Please try and post back.

JC,

shannondurst · Mar 15, 2020

Na the adjustment nut is just were I backed it off when removing. I will try the 1100 psi thank you for the help.

JC-jetro · Mar 15, 2020

I just came up with 1100 psi as just a number. I just want to see at what point it start squealing, backing it off to just stop and see what pressure that might be and if you can lift anything heavy enough right at that setting. I don't know how much you can actually squeeze the spring completely. Most likely that would be about 3/8" to shy of 1/2" at the most.

We need to figure this thing out. As Homer J, would say " Who'd thought a nuclear reactor would be so complicated

"

shannondurst · Mar 15, 2020

The squealing noise stops at around 1500 psi, but there is still some noise and vibration on small line and if you listen close almost like a purging sound, I have already blown out that line if curious.

JC-jetro · Mar 16, 2020

shannondurst said:
The squealing noise stops at around 1500 psi, but there is still some noise and vibration on small line and if you listen close almost like a purging sound, I have already blown out that line if curious.

@ 1500 psi does 3 point pick up your implement? how about @ 1450 PSI? Do you have automotive stethoscope? check to see if the vibration comes from the pump , it might be pump gears that is driven from timing cover gear that might not be meshing well or gears are chewed up a bit. Did you examine both gears. That vibration can transfer thru the pump to the line. There might be also some reading error with you gauge due to calibration.

If it picks up what you need at 1500 psi or 100 psi less then I would be happy and would not mess with it much more.

JC,

Ps. Purging sound might be bubble of air caused by cavitation. I know you cleaned the screen but partial plugging of the inlet screen can do that. if the oil is not the right oil it might foam in the pump and that is also not very good. You did have Ford 134a compliant hyd oil, right?

shannondurst · Mar 16, 2020

Yes it picks up implement and holds it, the pump is new I hope there is not gear issue, yes hydraulic oil is compliant, there is no foaming or airiation when inspecting through the fill port, they dont offer a reseal kit anymore for the control valve , you think the control valve could be the issue? Thanks for the help I appreciate it sir.

JC-jetro · Mar 16, 2020

shannondurst said:
Yes it picks up implement and holds it, the pump is new I hope there is not gear issue, yes hydraulic oil is compliant, there is no foaming or airiation when inspecting through the fill port, they dont offer a reseal kit anymore for the control valve , you think the control valve could be the issue? Thanks for the help I appreciate it sir.

I can't tell you for sure! I am sure pump internal gears are ok. it is a positive displacement type of pump. it can destroy itself in a short time if the inlet is not flooded or dead headed. Pump attaches to the timing cover housing pretty firmly with aligning threaded stud so can't see it being installed cockeyed. You said pump is new. is it new to you, re-manufactured, brand new or you overhauled it? we know for sure the discharge pipe from pump to relief device is clean. Relief and it's component they all look good. It appears that your lift is working and you can raise and lower so your spool must be okay. Your lift cylinder seal must be good since it can carry the weight. Can it do it with engine off?

We're down to figuring out noise at the pump or lil after in the discharge pump. if you don't have stethoscope then use a piece of 1/2 PVC pipe and touch to the pump, timing cover and discharge pipe to see if you hear anything abnormal. At the end if it just picks your implement I would let it be. I might see how low low I can back out the adjustment to just lift and so expose the system to least pressure possible but still being able to pick up the implement. if spool is causing the pulsation you should be able to hear that by manipulating the arm.

JC,

shannondurst · Mar 16, 2020

Yes pump is new never used I purchased new like $500, I will look into the other troubleshooting that suggested. What's dead head that you had mentioned, I hope I didnt cause pump failure from the other repairs.

JC-jetro · Mar 16, 2020

shannondurst said:
Yes pump is new never used I purchased new like $500, I will look into the other troubleshooting that suggested. What's dead head that you had mentioned, I hope I didnt cause pump failure from the other repairs.

There are different types of pump with different design and use. A centrifugal pump has an impeller. If the fluid is available at the suction volute it kind of grabs the water and slings it out (adding in Kinematic energy/velocity to it) if the intake is closed/blocked it will cause cavitation or if the discharge is closed it dead heads but impeller continues to spin and that energy will just boils off the liquid such as water. In a case of positive displacement pump , such as gear pump it cannot have a closed discharge as the pressure does not have anywhere to go unless it has an over pressure relief internally or externally. Dead heading is kind of having good intake valve in a piston that opens and closes OK but discharge/exhaust valve is totally closed and fused to the head. when piston comes up against the closed valve. Air is compressible but not liquid. So in a pump that transfers liquid something has to give and that always comes in the form of damage to some component. I hope my rambling made sense to you as it is passed my bed time.

Gear pump - Wikipedia