I've been looking at a used E42 trachoe. I'm on the fence about whether to buy it or not. Everything is tight, it has low hours (1872), all actuators are clean, and it starts up easy. However, it squeals a lot (with no load). Well today I went and looked at it again and checked all the maintenance points--more specifically the hydraulic sight glass. The fluid level when cold was above the hot in the red (the excavator boom and blade were in the proper position). The owner may have been run for awhile like this. The fluid level is almost above the red zone. What kind of damage can running a Bobcat excavator with too much hydraulic fluid cause?
Here's a video of it while overfull and squealing. You can't quite tell in the video, but it slightly sounds like it wants to die sometimes.
The sound may be distorted, but on my end the squealing sound like exhaust.
I know it's not as pronounced on video, but in person it's kind of a grinding squeal when manipulating the bucket. It got worse when ran at mid throttle.
Does bucket has power?
Yes, it'll will fully extend, contract, and dig. However, it doesn't sound great and sometimes with no load it sounds like it wants to slightly die. That's why I thought that it being extremely overfilled with hydraulic fluid may be binding something internally. I don't know though because I'm no expert at trackhoe mechanics. I'm going to try draining it down tomorrow and see if it clears up.
The squeal almost sounds like a relief opening up. It sure shouldn't do that just moving the bucket and dipper. I would tend to think it is more than just the hydraulic tank being over filled. But that is the place to start.
I think overfil just an morning overfil, if it will affect something then it will affect all the functions. Port relief or load check is more probable.
I'm going to try the drain tomorrow, but is the relief supposed to only open at full extension/contraction and each cylinder has a relief? Or is the relief a single valve for a whole system overload?
Not sure about minies but big excavators have port reliefs for every port (side of the cylinder) as well as main relief(s). Bucket not supposed to have holding valves and regen circuits. So what left is port reliefs, load check valves or bypassing spool.
Are these difficult fixes for someone mechanically inclined? Replacing them? The hour meter reads 1872 and everything on the machine is tight. However, I think it was a rental once upon a time.
So these are on the side of the cylinder and should they leak fluid if overloading occurs or if faulty?
It’s all depends on the degree of “mechanical inclination”. But I think it should be reflected in price. The worst case is scratched up bore, which can cost you new MCV housing, or the whole thing new or used.
No, on the side of the cylinder is holding or hose burst valves. If you have something on the side of cylinder of the bucket it’s probably hose burst valve. And I will be amazingly surprised to find it o BUCKET cylinder!
“And I will be amazingly surprised to find it o BUCKET cylinder!” Although to have counterbalance valves for thumb holding function is a good idea! Does it have a thumb?
It has aux ports and will come with a thumb. If it's a main valve then I should have issues with all the cylinders, correct? Any tests come to mind that I can use to single out the issue?
The manual should have run time test procedure. Also I would do deadheaded pressure test. The “ slow” and “low power” is kinda different things, and not always coincide.
Is it possible to aske seller to fix this?
Yes or I may just pass on the deal. He's only asking 28 for an E42 with only 1872 hours. Everything else on it looks great! However, he doesn't really know much about excavators so I'm not sure how well it's been maintained over the year he's had it. The air filter was dirty, the hydraulic overfilled, and there isn't much visible grease on the zerks. Also, we're down here in Hurricane Harvey territory so it's possible it was a flood victim. He had the fuel tank and fuel lines replaced because of a bad fungus outbreak.
Everyone has their idea of how to take care of diesel fungus but I would think replacing the fuel tank should not be done unless for 'some other reason', like rust from being under water. IMO you treat fungus with a Biocide. Put it in the tank and recirculate it. The fuel lines may have to be blown out if plugged but they usually will pass 'some fuel'. Replacing the tank is a drastic measure when a simpler solution works. Personally. . . I would walk away. A deal too good to be true usually isn't good or true.
Someone else's headache can be....someone else's nightmare.