Oil & Fuel Bad loader cylinder, and some nasty oil......

[nmu98]

Over the weekednd I took off my bad cylinder on the loader and sent it in for repair/replacement. Once I got it off, I put the oil in a bucket and it looked very bad ugly... I was expecting some pretty clean, clear oil, and I got some dark oil that looks to have a bit of metal in it.

In looking at the system, I would guess that once the loader is full of oil, the oil prretty much stays there and does not get swapped out with clean oil through use? So this oil never gets filtered, or some of it never gets filtered?

With about 40 hours on this tractor, and having some hydraulic issues when new, I think its going to be time to do a complete change of hydraulic oil.

 

[Phineas7]

If the lines to the cylinder hold more oil than the cylinder I could see where it would practicaly never be filter. If all the oil from the lines go into the cylinder and them some fresh, I'd think it would be mixed and eventually flushed. Wouldn't the oil turn dark from heat? Isn't most of the heat generated at the pump, or at the pressure bypass when any cylinder reaches full extension and the valve is till open? Are you thinking that the cylinder created the metal shavings and darkened the oil? I'd be concerned it's happening at the pump. I could see where if some shavings ever got into the cylinder, they'd have a hard time getting out though.

 

[nmu98]

Well. My dealer puts all the tractors they sell on a PTO dyno before they go out the door. I am assuming that maybe that broke things in a little faster than I would have normally, and that the metal shavings are fairly common in this brand and size tractor.

So my thought was that maybe a lot of stuff was floating around from that break in, and caused some of my 3 point issues that went away, and could have contributed to this cylinder going bad?

So when I do a fluid change, I think I will empty each cylinder, if they do not flush.

The oil was not black like engine oil, but it was not overly clear. might be normal, but the small metal particals do not need to be there.

 

[kennyd]

In looking at the system, I would guess that once the loader is full of oil, the oil prretty much stays there and does not get swapped out with clean oil through use? So this oil never gets filtered, or some of it never gets filtered?

I think this is the case, very little if any ever gets back into the common sump.

So when I do a fluid change, I think I will empty each cylinder, if they do not flush.

That's certainly not a bad idea! It will be a messy PITA but will probably ease your mind to do it.

 

[nmu98]

Well, I need some advise......

I sent in the bad cylinder. It had some pretty good leak by when I tested it. I got a call from the dealership telling me that I sent them in the wrong cylinder.... The service manager had me talk to the tech. After talking witht he tech and explaining how i tested it, he then told me that I probably have the right cylinder, and the nylon ring was loose, and one of the orings from the new kit fit much tighter. AND, when he put it back together, it was a lot stiffer.... He thought it moved to easy before...

I uissually have good luck with this dealer, but WTF... Why call someone and tell them they sent the wrong one, then backstep.

So, when i put it together, I need to bleed the air out, and test it again. Can I do anything else to ensure this one is put together correctly? Any other tests than bottoming it out and pulling one "releif line" and looking for leaks?

 

[AKfish]

This is a good discussion... not exactly sure where the cylinder problem will go with nmu98's dealer but I sure hope they don't try to "skate" on the warranty issue.

Nonetheless, this situation brings up a puzzling question -- how much hydraulic fluid circulation occurs between the FEL (or backhoe, etc) and the main hydraulic sump?

I've never fully extended the FEL cylinder and then measured the total volume (could be calculated, too) and then compared that volume to the fluid volume in the lines (from the SCV connectors on the tractor).

If I was a design engineer (that would be a BIG stretch..) and was considering the hydraulic operation of an FEL - I'd WANT that fluid to be exchanged and subsequently filtered during the operation of the implement --- that seems inherently logical to me.

The idea that dirt and other contaminants (metal shavings) would always be trapped and not removed from within the cylinders sounds like a dead-end certainty that the cylinders will have a shortened operating life.

AKfish

 

[nmu98]

Well, from testing tonight, my cylider is fixed. I after, I pulled the other dump cylinder and manualy emptied it. There were 2 decent size shavings in there.

Are they in there from the factory, from the tractor, or both? Will never know. I am going to drop the hydo fluid soon and see what I find the the filter and screen.

I will clean out all the fel lines and cylinders before I change it so I get fresh new fluid.

 

[mfreund]

Hey, could you post some pictures when you bleed the cylinder? I never thought about it and will bleed loader cylinders in the spring!! It makes sense to me that some of the hydraulic fluid never gets circulated

 

[nmu98]

Sure, It might be a few weeks. i have to buy the fluid this weekend, and get time away. It going to take a while since I think there will be a lot of cleanup....

 

[jd110]

If you have contaminated oil, it is a good idea to manually flush out cylinders to try and get as much contamination out as possible. But, the cylinders do get filtered oil everytime you cycle the loader. It does help if you occasionally extend and retract the cylinders fully to make this more efficient. While not 100% of the oil is exchanged, I am sure it is at least 80% when the cylinder is fully cycled.