Morbark 2070XL Hydraulic Lift Not working

[TreelineNH]

Guys,
I have I have a Morbark 12" chipper with hydraulic lift. The lift function as of recently has become super sluggish, or almost not existent. This is something that has just recently come to my notice.

-Machine is a 2004 and only has 220hrs.
-Changed the filter yesterday, and topped off the fluid
-Both drive motors work fine and are responsive
-No leaks that I can see
-Tried cracking the lines, hoping there was possibly air in the system (That's the oil you see)
-I don't have a pressure gauge to check pump output but manual says 3000psi

From my own research I think its probably either the pump not pumping at the correct pressure or Pressure relief valve?

Where is the pressure relief valve, my manual has no diagram but talks about it? Attached are some pictures maybe your guys can point me in the right direction. Thanks.

Tom

 

[craneguy1]

Not familiar with morbarks...but most bandits without autofeed have a pressure relief adjustment built into each hyd valve...each valve set to a different operating pressure...that being said, normally the lift cylinder operation goes out first.

 

[TreelineNH]

Not familiar with morbarks...but most bandits without autofeed have a pressure relief adjustment built into each hyd valve...each valve set to a different operating pressure...that being said, normally the lift cylinder operation goes out first.

-Its equipped with autofeed.

-So with a weak pump/pressure lift would be the first function to be lost?

Thanks for the response.

 

[craneguy1]

First thing you would check out on a bandit with autofeed is the main relief...you need a gauge and probably a makeup of fittings/ bit of hose to plug it in...a drop of only 100 psi actually can make a buge difference in performance...if main relief is good, then adjust the relief that controls the lift function. I doubt your pump is shot.

 

[craneguy1]

In pic one; what is under the little red cap on the valve bank right next to the bent to hell drum lock bar? Looks like it might be important... allen head under the cap secured with a lock nut?

 

[TreelineNH]

What does the main relief look like? Are the controls called relief valves? Sorry for the ignorance, Im new to hydraulics all together. If the controls are "relief valves" where do I adjust them? See attached

Thanks for the help.

 

[craneguy1]

Controls are not relief valves. What is under the red cap? Could be right there.

 

[TreelineNH]

Micro burst came through a few weeks ago and a tree fell on my chipper. Only the bar was bent no of the fittings or controls. Has work fine as until recently. Actually fixing the bar today. Thanks for the help!

 

[classictruckman]

Think the red cap covers a oil sample hook up

 

[craneguy1]

Imagine that....a tree guy with a tree problem...

 

[flyingsquirrel25]

Thats a bummer, with that tree hitting the chipper. If you are worried the pump may not be putting out enough pressure to run both the wheels and the lift, you could put the wheels in neutral and try the lift. If it operates normal then you probably have a pump pressure problem. If it Is still sluggish then it's probably within the lift valve or hoses.
Please keep us up to date on the progess. Mine is three years older, never know might have the same problem someday. Thanks

 

[TreelineNH]

Thats a bummer, with that tree hitting the chipper. If you are worried the pump may not be putting out enough pressure to run both the wheels and the lift, you could put the wheels in neutral and try the lift. If it operates normal then you probably have a pump pressure problem. If it Is still sluggish then it's probably within the lift valve or hoses.
Please keep us up to date on the progess. Mine is three years older, never know might have the same problem someday. Thanks

I was just glad I wasn't working at the job site. I worked till 4:30, storm came in about 5:30.

Ya putting the drive wheels in neutral helps a bit, but it's super slow both ways. I'm going to call morbark today, and try to get my hands on a gauge to put on after the controls to see what pressure is going to the pistons.

 

[TreelineNH]

Talk to Morbark today and hopefully I have the issue sorted. I think I'm getting leak by on both pistons. The way I check it was to start up the engine, and place the lever to the crush/close position. The oil will flow from the top hose (and be under pressure), but should not come out of the bottom hose (But only when the lever is in the closed position) ..... So while I had the lever in the closed position, I unhooked the bottom hose from the bottom of the cylinder, and sure enough oil was getting by coming out from the bottom of the cylinder. It was actually leaking on both cylinders.

I ended up ordering new cylinders from Morbark for about $250 each. I got quoted anywhere from 200-250$ (each) to rebuild the ones I have, so it was a no brainer to buy new. New cylinders will be here Thursday, and I will install this weekend and share the results.

 

[craneguy1]

Crazey to have them both go out with so little hours...always wondered about that while watching them move while chipping...never had a single one go out...even after 20+ years...granted the most hours we've put on one with that sort of setup is about 6k. Let us know x2

 

[TreelineNH]

Ok, got the issue sorted out!!!!! So I ordered two cylinders, and replaced one a few weeks ago. To my dismay it didn't make a difference. I got the idea to block off the old cylinder and run just the new one... and sure enough it worked like a charm. So yesterday I replaced the right side, and its working like a dream! Couple of things that sucked....

-The top pins had no grease fittings so I literally had to cut them out. It took many hours and curing to get those dam things out. I might see if I can get a new pin with a fitting built in for the tops since the bottoms have zerks.
-The right cylinder was behind the hydraulic tank/fuel tank. Had to loosen it up to get in there.
-The new cylinders has different size threads for the fitting, so I ended up having to track down and buy new fittings and two new hoses ($200.00).

I tested the cylinders when they were out with my compressor, and sure enough both were leaking by.

 

[classictruckman]

Get the old ones resealed so you have spares ready for the next time it happens