4410 3 pt and loader issue

[wango tango]

hey all

at the end of the season last year i started noticing my 3 pt hitch when raised would every now and again bump back up to the top. in other words it seems like it would go down some and then the hydraulic system would bump it back up to the desired position.

both my 3 pt and loader will slowly drop too if i leave the tractor overnight, for example. i'm not sure how much is normal or if this is related to the original issue i posted above.

what could be the common culprit for this? is there a leak somewhere? no fluid comes out.

fwiw, i changed the hydro fluid recently too. it needed it as i have never done it since i owned it.

tia!

 

[Mark Petrowicz]

Wango,
Always check with the John Deere customer service guys but you might have some air in the hydraulics , is it chattering also? its kind of like bleeding brakes on a car if you get air i the system it will chatter also. other wise check your resivor to see if its filling up when your hydraulic pumps not running thats a sign of back flow by pass which can be a simple fix if you have an in line back flow valve or a real problem if the pump itself is allowing backflow when it is not running hence the drop in pressure. you should not leave any hydraulic piston under pressure by the way ...

 

[wango tango]

doesn't seem that it chatters. it'll hold at the top position, then i feel it bump back up. i dont notice it dropping - its not fast.

i'll try to bleed it anyway - is there a bleeder valve or something? what is the procedure to do it?

 

[wango tango]

does anyone know how to bleed this? i recently changed my hy-guard fluid, i guess this is where some air could have potentially gotten in the system?

 

[kennyd]

Open Center Hydraulic Systems like these do not need "bleeding", they self-purge the air to the tank while in use. Air trapped in cylinders will get pushed past the seals.

Did you clean the return screen and replace the filter when you changed the oil?

 

[Tx Jim]

What your tractor 3pt is doing is referred to as hiccuping. The 3pt circuit has a small internal leak allowing draft arms to drop then the hyd's correct and raise 3pt back to original position.

 

[wango tango]

yes, on both. the return screen was gunked up good. took a bit to get all of that out....had some hard crusty stuff in it.

 

[wango tango]

What your tractor 3pt is doing is referred to as hiccuping. The 3pt circuit has a small internal leak allowing draft arms to drop then the hyd's correct and raise 3pt back to original position.

i figured it may have been something like that. how to troubleshoot/repair?

 

[Tx Jim]

Only way I know to repair is to remove rockshaft cover and have a look at the RS control valves and piston seal

 

[DFB]

Overnight leakdown of loader and raised 3 point attachment is common and is not usually a sign of a problem JD manuals have hold and drop tests that can troubleshoot internal rockshaft leakage problems. The sensistivity valve controls moving and holding lift arm position and the desired position is held by a spool valve on mine. Have you moved the speed adjustment at all. You are saying it is doing while the tractor is running correct?