bandit 250xp not lifting?

[imagineero]

Hi guys,
I've been having some trouble with my chipper. The feed roller lift works great first thing in the morning, easily lifts the top roller all the way up. But as the day goes on, it gets progressively weaker, until it barely lifts at all, like maybe only an inch or two. Next morning, it's fine again. What gives?

Reservoir still pretty full with everything running, only thing I can think of is maybe cavitation? I'm going to try draining the fluid and replacing it next week. Everything else on the chipper works fine, the rollers have plenty of power, and crush works great. Anyone got an idea?

Shaun

 

[imagineero]

Have you put a pressure gauge in the system?

Low pressure can act like that.


It's not cavitation.

I've got a gauge but I don't really know where to plumb it in, or how to adjust the pressure. Do you put it before the first valve on the 'out' side of the pump?

Shaun

 

[treeclimber101]

Check your filter and see if there's shavings from the pump in there , the fluid may be thinning with heat or possibly water , I would start with a flash light In the filter and take a look see

 

[imagineero]

Check your filter and see if there's shavings from the pump in there , the fluid may be thinning with heat or possibly water , I would start with a flash light In the filter and take a look see

Sounds like a good idea. Anybody know roughly how many gallons for a full tank? About 10 maybe?

 

[treeclimber101]

Sounds like a good idea. Anybody know roughly how many gallons for a full tank? About 10 maybe?

You have a gauge on the cap , right ? Mine has a moving gauge and also a reader stick . My bobcat was acting like that , I had up and down but when I tried to curl the bucket I lost all power ..... But I could still pick it up and down at full weight .... Turned out that the impellers on the pump were shot and when I really opened up the system it couldn't handle it all and would lose power . I pulled my hair for almost a month checking all the valves and then finally I cut the filter in half to see large shards of metal lodged in the filter hidden well ....

 

[imagineero]

You have a gauge on the cap , right ? Mine has a moving gauge and also a reader stick . My bobcat was acting like that , I had up and down but when I tried to curl the bucket I lost all power ..... But I could still pick it up and down at full weight .... Turned out that the impellers on the pump were shot and when I really opened up the system it couldn't handle it all and would lose power . I pulled my hair for almost a month checking all the valves and then finally I cut the filter in half to see large shards of metal lodged in the filter hidden well ....

Mine's the older style, no gauge on the cap just the stick. Im just trying to figure how much oil to buy so I only have to do one trip to the store.

Stories like yours make me depressed :-( I just replaced the pump on my truck, it runs the tip bin. Cost for the new pump (parts only) was $1100.

 

[KenJax Tree]

I believe the last time we changed hydro fluid on the 250 it was 13 gallons

 

[dbl612]

seeing that you mentioned that everything was working well throughout the day except for the feed roll lift, i would suspect that the packing in the the lift cylinder is bypassing internally as the oil gets hot during the days use. easy way to check is when oil is hot, disconnect the pressure down hose on the cylinder, plug it and see if oil comes out of the open port on the cylinder (the one you took the line off of). move the control lever to raise the rolls and if a continual flow of oil comes out (after the initial burp of oil that is on the open cylinder side) you have a bad cylinder packing. simple checks first. let us know how you make out. if a bad packing should be a simple inexpensive fix.

 

[treeclimber101]

Mine's the older style, no gauge on the cap just the stick. Im just trying to figure how much oil to buy so I only have to do one trip to the store.

Stories like yours make me depressed :-( I just replaced the pump on my truck, it runs the tip bin. Cost for the new pump (parts only) was $1100.

Bobcat cost me 300.00 that's it .... Sorry man I always think the worst and hopefully pleasantly surprised .

 

[treeclimber101]

seeing that you mentioned that everything was working well throughout the day except for the feed roll lift, i would suspect that the packing in the the lift cylinder is bypassing internally as the oil gets hot during the days use. easy way to check is when oil is hot, disconnect the pressure down hose on the cylinder, plug it and see if oil comes out of the open port on the cylinder (the one you took the line off of). move the control lever to raise the rolls and if a continual flow of oil comes out (after the initial burp of oil that is on the open cylinder side) you have a bad cylinder packing. simple checks first. let us know how you make out. if a bad packing should be a simple inexpensive fix.

Wouldn't he be losing the overflow through the dust cover .... I thought the double wall cylinders couldn't drain the fluid back into the can once its in the outside .

 

[imagineero]

I just put a gauge in between the handle and the lift cylinder, on the lower hose. The other thing is a flow control valve, it's open, I just put it in there because I didn't have the right fittings to put the gauge only. Pressure starts at about 500psi when you lift, and raises with the roller to about 900 which sounds kind of low to me. I noticed that the box doesn't quite reach the top, it stops about an inch short so it never actually max's the pressure out.

I'll give it a try tomorrow and see how the pressure is later in the day when it won't lift much any more. So you guys are saying that if I remove the top hose, there should be no oil coming out, and if there is it means the cylinder needs a rebuild?

If I turn the flow controller off, so no fluid can get through, and the pressure goes way up, does that tell me pretty much the same thing, ie. the pump can supply a lot more pressure, but the cylinder is leaking?

Where is the pressure adjustment?

Shaun

 

[gregory sojka]

lift problem

Hi guys,
I've been having some trouble with my chipper. The feed roller lift works great first thing in the morning, easily lifts the top roller all the way up. But as the day goes on, it gets progressively weaker, until it barely lifts at all, like maybe only an inch or two. Next morning, it's fine again. What gives?

Reservoir still pretty full with everything running, only thing I can think of is maybe cavitation? I'm going to try draining the fluid and replacing it next week. Everything else on the chipper works fine, the rollers have plenty of power, and crush works great. Anyone got an idea?

Shaun

I had the same problem last month on our 280 bandit it was the hydraulic pump , new one in and now it really moves .

 

[imagineero]

Thanks for your advice Del,
Every piece adds a bit to the puzzle ;-) I'll give it a go tomorrow and see what I find, will report back either way. In dream land the pressure needs increasing. In a slightly less bright future the lift cylinder needs replacing/rebuilding. In all probability the pump is stuffed, it's 15 years old and has over 2500 hours on it. Most likely the pump and the cylinder (and maybe some of the valves) need replacing. And all the hoses too! hehe.

Shaun

 

[imagineero]

I realised almost immediately when I got to the first job today that I put the gauge on the wrong side of the flow meter. It should have been on the other side :-(

We got east for a few days now, I was hoping to get this sorted and paint the chipper over the break, got the paint and the $$$ stickers, don't want to do a nice paint job then wreck it by spilling hydraulic oil all over the chipper so I guess I'll just have to leave it for a few more days.

Shaun

 

[CalTreeEquip]

Sounds to me like your control valve needs new O rings. If your getting 2000 psi or so when you close the control valve you installed then the pump is fine and the pressure relieve valve is working as well. It could be the cylinder but I have never had to replace one of them, replaced or rebuilt a bunch of control valve though. They take a lot of abuse. If the feed wheels work well then its probably not the pump. If the wheels are spinning and you hit the lift cylinder and it doesn't go up and the wheels stop turning or turn slow then it might be the pump. If you then put the wheel in neutral and the cylinder does go up, thats a pressure problem as well, could be the pressure relieve valve. It all depends on how the hydraulics are configured and I have seen different configurations one them. I usually draw a schematic of the system before I do anything since the placement of the different control valves effect the flow of pressure through the system. It helps to look at a map while your working on it. Also take a few pics so you don't reattach the hoses in the wrong place. I once replace a hydraulic pump because I didn't have pressure because the knucklehead fool city mechanic switched two hoses.

 

[imagineero]

Just a follow up on this. I finally got the pressure gauge and valve mounted correctly, and found that the machine was making 1000psi when cold lifting, but would drop down to 500 when hot. Closing the valve and activating lift (so no fluid could pass through and the gauge saw the full pressure) gave me over 2,000 PSI which was a pretty clear indicator the lift/crush cylinder was internally bypassing so I ordered a replacement lift/crush cylinder and fitted it. The problem was immediately solved and it now works very well, lifts easily to full open and is easy to control. The swapover was straighforward.

 

[CalTreeEquip]

Man that took a while to fix. What the new cylinder cost you?

 

[dbl612]

Just a follow up on this. I finally got the pressure gauge and valve mounted correctly, and found that the machine was making 1000psi when cold lifting, but would drop down to 500 when hot. Closing the valve and activating lift (so no fluid could pass through and the gauge saw the full pressure) gave me over 2,000 PSI which was a pretty clear indicator the lift/crush cylinder was internally bypassing so I ordered a replacement lift/crush cylinder and fitted it. The problem was immediately solved and it now works very well, lifts easily to full open and is easy to control. The swapover was straighforward.

see #9 reply.

 

[imagineero]

Man that took a while to fix. What the new cylinder cost you?

I fixed it more than 6 months ago, but forgot to post a follow up. I was linking this thread to another and realised i never posted after getting it sorted. From memory i think the replacement cylinder was about $450 from bandit in Australia.

The swap out was pretty straightforward. I received some pretty good advice here which helped in trouble shooting the problem. Hydraulics aren't so easy to diagnose without gauges, but having some gauges now is a big help. The bits and pieces are so expensive you don't want to just go replacing them blindly

 

[imagineero]

see #9 reply.

Thanks, i already read it ;-)