Naa hydraulic problem

[Graham7of8]

was trying to set up a new plow today on my naa. Test the hydraulics befor I got hooked up by riding them up and down with my full 220lbm no problem. Though I seenm to have lost a little position control. Hooked up to my plow and it struggled to lift the plow (400LBM) but did lift it up just not to full hieght. Plowed the first row and no more lift. I back the tractor up and took the plow off still no lift. I just rebuilt the hydraulic pump and the hydralic ram assembly. I had test the system after and every thing was running great. No drifting ,great control and no lagging. any thoughts on what this might be?

thanks
Bill

 

[Brian Allen]

"Graham7of8"
Park the tractor on a hill sideways, or block up the side where the inspection cover is until the fluid level is below the cover. I use a barn hill.
Be careful that you properly block the wheels to prevent the tractor from moving.
With the tractor running at an idle look in the inspection cover and see if the relief valve is dumping, if you are lucky and it is bypassing, you may be able to replace it without removing the top cover.
If not, you have to disassemble again.
Post back
Brian

 

[souNdguy]

pressure test it..

post back

 

[Graham7of8]

Soundguy,Pressure test it from the manifold cover or the test port on the side?

 

[souNdguy]

yeah... pressure is pressure.

don't matter if top of the pump, under the seat, or the port on the side of center housing.


soundguy

 

[Graham7of8]

I did the poor mans pressure test on the top one ( I crack the fitting and look for oil flow) I got no pressure at the top fitting. I also peeked in the fill port and there was no oil pouring out of the ram cylinder. By the way thanks for the input on the clutch rebuild it went well, works better than ever.

 

[JMOR]

The side test port will give you a little more information, because, if the system is in bypass mode (which can happen with a stuck unloader valve, the pressure is only about 40 PSI (set by back-pressure valve) and that is too low to open the check valve, thus no pressure at top plate test port, but the 40PSI would show at the side test port & at the least let you know that the pump is pumping. If it isn't you may be able to prime it at the plug on the pump itself.

 

[Graham7of8]

I was able to block the tractor and remove the inspection cover last night . Looking through the inspection cover I did not see or feel flow from the relief valve. I did observe though that the potion control valve spacing seemed to be larger than 3/16th do you think this way be problem?

 

[JMOR]

(quoted from post at 12:28:37 04/21/11) I was able to block the tractor and remove the inspection cover last night . Looking through the inspection cover I did not see or feel flow from the relief valve. I did observe though that the potion control valve spacing seemed to be larger than 3/16th do you think this way be problem?

hat 3/16 is measured with a particular set of circumstances: lift arm position, touch control lever position, and draft control position. Did you have all those 3 things in specified position for your measurement? If not, it means nothing. What about flow out the side test port?