Weird response from hydraulics at start up

[willg]

l2501 w 150 hrs, has a strange response out of the hydraulics when first run after sitting overnight.
I have been getting a very noticeable "jerky", "crunchity" feel out of the first moments of use when actuating loader, etc. The only thing i can compare it to is a sticking brake caliper i replaced on my truck ,compressing the piston in had a very jerky, un smooth operation. After this initial weirdness, nothing else unusual. i did fluid/filters@ 50 and if anything have too much hyd fluid in there now. Anyone else experience this?

 

[TheOldHokie]

l2501 w 150 hrs, has a strange response out of the hydraulics when first run after sitting overnight.
I have been getting a very noticeable "jerky", "crunchity" feel out of the first moments of use when actuating loader, etc. The only thing i can compare it to is a sticking brake caliper i replaced on my truck ,compressing the piston in had a very jerky, un smooth operation. After this initial weirdness, nothing else unusual. i did fluid/filters@ 50 and if anything have too much hyd fluid in there now. Anyone else experience this?

When was the last time you greased the pins?

Dan

 

[Henro]

What does the “etc” you mentioned refer to?

 

[willg]

pins are lubed. loader lift, bucket curl, moving the machine, causes momentary jerkiness. Have had a box blade attached and do forget to lower it down alot?

 

[TheOldHokie]

pins are lubed. loader lift, bucket curl, moving the machine, causes momentary jerkiness. Have had a box blade attached and do forget to lower it down alot?

Sre the brakes releasing?

Dan

 

[willg]

noticed it without moving the machine

 

[PoTreeBoy]

Assuming this is an L2501HST. Check the fluid suction line from the sump, through the filter, to the hydraulic pump. Leaks are a common source of air getting in.

 

[NCL4701]

I know nothing specific about your machine so this may be worthless.

1. Had, or more accurately operated and worked on, a Ford (tractor) many years ago with jerky hydraulics when first started AND when idling. Worked fine after about 5 minute warm up and at some reasonable working RPM above idle. Might have worked fine at high RPM when cold but never tried that as I was convinced by experience my father would appear out of thin air and smack me upside the head if I throttled it way up before the temp needle moved.

Ran it that way until winter “work on equipment” time. Had a pinhole leak in the suction line going into the pump. Hole was big enough to make the pump sputter at idle and on startup but at higher RPM there was enough flow that there wasn’t a noticeable drop off in performance. Might be worth checking the suction side of the circuit to make sure everything is tight and in good shape.

2. On my L, the 3 point height control lever is held in place by one bolt or stud or whatever. Too tight and you can’t move it. Too loose and it will move by itself. Mine was “jerky” when I first got it because the nut/bolt (it’s been a while and I don’t recall) was a wee bit tight so maybe someone could move it smoothly but I couldn’t. Loosening only about 1/8 turn smoothed it out. I figured the guy that set it was probably beefier than me and it moved smooth for his gorilla arm strength.

3. Only 150 hours. If still under warranty, might consider letting your dealer sort it out.

 

[willg]

a cursory look under the machine did not reveal anything unusual, besides 2 grease zerks i did not know were there. If there was air entering the hydraulic system would there definitely be fluid leaking out somewhere? Could third function be letting air in when changing implements? my sight glass is completely full btw

 

[NCL4701]

If there was air entering the hydraulic system would there definitely be fluid leaking out somewhere? Could third function be letting air in when changing implements?

An air leak on the suction side of the circuit doesn’t necessarily translate to a fluid leak. If there’s a leak on the suction side, the problem isn’t fluid escaping, it’s air coming in to an area that should be fluid only, no air.

Assuming you have some sort of quick connects (you don’t need a wrench to connect/disconnect the implements hydraulics) changing implements shouldn’t be a problem. A small amount of air getting into the lines on the pressure side of the circuit would self purge anyway as the cylinder cycles with use and whichever line has air in it returns fluid to the sump. The sump has air in it normally. If the fluid is halfway up on the sight glass, everything above it is air.

If it’s an air leak problem, the leak would be in the lines, fittings, filter, and/or anything else between the pump’s pickup in the sump and the pump itself.

In maybe a bit simplistic terms, the suction side of the circuit is like putting a hose in a bucket of oil (the sump) with the other end stuck on the inlet side of a pump. Of course there’s probably a filter in the middle of that “hose” and there’s probably a bunch of stuff in the way so it’s not all right in front of your face but that’s the basics of it. Just like trying to suck a milkshake through a straw with a crack in the side of it, it ain’t going to work very well if there’s an air leak somewhere between the sump and the pump.

 

[PoTreeBoy]

If there was air entering the hydraulic system would there definitely be fluid leaking out somewhere? Could third function be letting air in when changing implements?

No, there is almost no pressure before the pump, so there may not be a drip. If you see any evidence of seepage, there's a leak. Squeeze any suction hoses and see if there's a crack. No again, any air on the discharge gets passed off when it returns to the sump.

You've reminded me that I need to check the clamps on my L35. I had a chirp when I shifted mine (glideshift). I replaced all the suction hoses and it stopped. But lately, it's started doing it again, not as bad.

I'm reluctant to mention this, but as a last resort it might help. Put a little (little, as in 5 psi) air pressure on the sump/transmission case and then check for leaks.

 

[TheOldHokie]

I find it unlikely that a tractor with 150 hours on it has a bad suction side hose but maybe a loose hose clamp. Or maybe a bit of drainback in the filter

This does not sound like its really a problem. I'd simply warch it and "Keep on Tractorin' "

Dan