Ford 1720 3 point lift problem. I need your HELP!

[BigolBill]

Bill,

I'd start with simplest thing first. Can you lift the arms without load on it? if so then turn tractor on, by force of hydraulics lift the arms up with nothing hanging from it. While the engine is running and arms up turn CC (clockwise ) the rate of drop knob right under the seat. turn tractor off and observe if the arm drops. You might put something a bit heavy or stand on the arms to see if it drops quicker. If the arms drop, would be a very strong tell tale sign of lift piston is leaking by. If pump flow is greater the leakage rate then you can lift stuff based on their weight with all the symptoms you described. do you have a loader?

JC,

I believe I already can answer that(maybe) as the arms did go down on their own when I left them elevated with engine off while loading my 3pt hopper spreader.( this was while I had left and came back a few hours later to fill it...only difference was that I did not turn the knob all the way clockwise) otherwise I can go try it and follow up with you....?

 

[JC-jetro]

I believe I already can answer that(maybe) as the arms did go down on their own when I left them elevated with engine off while loading my 3pt hopper spreader.( this was while I had left and came back a few hours later to fill it...only difference was that I did not turn the knob all the way clockwise) otherwise I can go try it and follow up with you....?

Bill,

Having rate of drop knob closed make a huge difference in correct diagnosis. with the knob closed,if the arm drops then 9 out of 10 it would be the piston seal and very unlikely possibility of lift piston over pressure relief mechanism in (TC style Ford tractor) lift piston head. Observe it with the valve closed and report back. In what you described without the rate of drop closed then you have additional pathway back to possibly a leaky lift spool valve.

JC,

 

[BigolBill]

Bill,

Having rate of drop knob closed make a huge difference in correct diagnosis. with the knob closed,if the arm drops then 9 out of 10 it would be the piston seal and very unlikely possibility of lift piston over pressure relief mechanism in (TC style Ford tractor) lift piston head. Observe it with the valve closed and report back. In what you described without the rate of drop closed then you have additional pathway back to possibly a leaky lift spool valve.

JC,

Thanks, JC....will get back to you ASAP!

 

[BigolBill]

Thanks, JC....will get back to you ASAP!

Well JC, I followed up on what you suggested...I first raised the arms with tiller attached closed off valve- it did not drop whatsoever. Then I removed the tiller and raised the arms,closed the valve off and no drop either...I did notice my arms are raising better today... But still somewhat hesitantly...what next?

 

[JC-jetro]

Well JC, I followed up on what you suggested...I first raised the arms with tiller attached closed off valve- it did not drop whatsoever. Then I removed the tiller and raised the arms,closed the valve off and no drop either...I did notice my arms are raising better today... But still somewhat hesitantly...what next?

Bill,

Good info. That rules out piston seal issue specially with a heavy tiller hanging from the arms and it not dropping. Do you have a loader? any remote? anything to divert flow away from the 3 point? if answer is no to each question then there might be two possibilities. Either the pump is getting tired, leaky seal within the pump or pump is pumping enough, but flow is by-passed thru the relief device. Do you know where you main relief device is downstream of the pump discharge? does it chatter while lifting anything heavy?

At this point you need to see pump flow and pressure. I would use a liq filled pressure gauge at the lift piston head assembly and would check the pressure to see if that gives me a clue. I'd see what pressure pump develops at rated pto RPM and try to compare and contrast with Owner's manual. Overhauling a pump is not real simple and you certainly would not want to do it unless you're sure beyond any doubt that is the problem. Report back with your findings to see where we go from there.

JC,

 

[BigolBill]

Bill,

Good info. That rules out piston seal issue specially with a heavy tiller hanging from the arms and it not dropping. Do you have a loader? any remote? anything to divert flow away from the 3 point? if answer is no to each question then there might be two possibilities. Either the pump is getting tired, leaky seal within the pump or pump is pumping enough, but flow is by-passed thru the relief device. Do you know where you main relief device is downstream of the pump discharge? does it chatter while lifting anything heavy?

At this point you need to see pump flow and pressure. I would use a liq filled pressure gauge at the lift piston head assembly and would check the pressure to see if that gives me a clue. I'd see what pressure pump develops at rated pto RPM and try to compare and contrast with Owner's manual. Overhauling a pump is not real simple and you certainly would not want to do it unless you're sure beyond any doubt that is the problem. Report back with your findings to see where we go from there.

JC,

I do not have a loader...it does make squelching noise as it raises the tiller...I have no idea where the pressure relief is that you mention ... I did just pick up a shop manual download...and am familiar with where to hook up a pressure guage...will check that out next... As soon as I can track one down to borrow or pick up reasonably...

 

[JC-jetro]

.it does make squelching noise as it raises the tiller......

That is the important clue. I have a strong suspicion that your relief device is set too low or valve part of it does not seat well causing some "belching" of the hyd oil back to the diffy. Put the gauge on, lift the tiller up to the max you can, observe the pressure when the pressure relief valve activates. I'm having a bit of problem with NH site loading up diagram, follow your discharge pipe out of the hyd pump (smaller dia pipe) and it has to go to some block where the pressure relief device is. Cause the lift to chatter and listen for it , it'll tell you where it is.

JC,

 

[BigolBill]

That is the important clue. I have a strong suspicion that your relief device is set too low or valve part of it does not seat well causing some "belching" of the hyd oil back to the diffy. Put the gauge on, lift the tiller up to the max you can, observe the pressure when the pressure relief valve activates. I'm having a bit of problem with NH site loading up diagram, follow your discharge pipe out of the hyd pump (smaller dia pipe) and it has to go to some block where the pressure relief device is. Cause the lift to chatter and listen for it , it'll tell you where it is.

JC,

Well, pressure guage is showing about 1800 psi when raised up and lift lever is sitting in notched position... 3pt seems to be working better each time I mess with it(hesitation disappearing)...? I was just reading a section of my manual that stated to leave your 3t in the lower position during long periods of storage to prevent corrosion of the lift cylinder... Maybe I was having issues due to it being somewhat seized up? And as I use it more if remedies itself more so??? What do you think

 

[BigolBill]

Sorry 3pt should be left in raised position during storage... Mine was down...

 

[BigolBill]

Sorry 3pt should be left in raised position during storage... Mine was down...

Went ahold and changed Hydraulic fluid and filter... Pressure jumped to 2000 psi and raises and lowers with ease no more issues at this time! Yeehah!:cool2: