Losing power???

[intothewoods]

Hey gang.. I have a Kubota B7800 with 560 hours on it that has recently been losing power... It barely makes it up a maybe 20 percent grade that it used to zoom up.. The front loader seems weak too. I had lent it to a friend who said he put in more hydraulic fluid for me, then I found out it was the stuff he uses for his log splitter which is a lot lighter weight than the UD I normally put in it.. could that be part of the problem? Had it serviced about 80 hours ago so most filters should still be good... any other thoughts out there?

 

[aczlan]

Does the engine bog down, or is the tractor just slow?
If the engine bogs down, I would look at the fuel and air filters, otherwise, I would change the hydraulic fluid and the associated filter(s).

Aaron Z

 

[intothewoods]

Thanks Aaron, it feels more like it's just slow all the way around... from the moment I step on the gas. I just browsed an earlier thread that mentioned the filters, but I really don't think that's the problem because they're pretty new... so that's why I was wondering about the potential hydraulic fluid problem.

 

[aczlan]

How much fluid did he add? That takes 3.83 gallons (per Messicks), so a quart or so shouldn't have affected it much but a gallon would.

Sounds like it could be a fluid issue (assuming that there isnt something that was overlooked, like the transmission being in low range)

Aaron Z

 

[intothewoods]

Well... I've changed out the trans/hydraulic fluid and all filters including the fuel filter... don't really feel much of a change in it. It still really drags going up that little incline at anything under 2K rpm in mid gear and it used to roll right up it.... I've run out of daylight, but it seems it may be something that those simple procedures don't fix...

 

[Mark Page]

I had exactly the same problem with my 45hp Massey. It barely pulled a hill that was never a problem. The sight glass was clean, so a put in a new filter element anyway, same problem. Started pulling fuel lines from the injector pump to the gas tank and blowing them out with air, no blockages found until I got to the mechanical lift pump under the tank. There was a tiny pc of green material stuck in a screen type filter. Fired it up and it ran better than ever. I can't believe that little pc of debris could cause that much power loss.

 

[intothewoods]

Replaced the fuel, blew out all the lines, changed other fluids and filters as listed above and still no luck... I think it's time for a visit to the dealer... crud...

 

[ShenandoahJoe]

When my little Kubota started feeling that way, it was a clog in the air intake. But I'm sure you checked that already. How are the RPMs?

 

[intothewoods]

Thnx SJ...I did go through all the air intake possibilities, including new filter. Since rpm's are adjustable.. the engine, when I'm not moving or when there is no load, sounds fine... no brake binding.. it's rolls in neutral. I'm stumped unless it's something internal..

 

[mikehaugen]

If it is not bogging down (rpm's staying about the same) then I would say probably not engine related and more hydro- related, especially if you are noticing an issue with the loader. I recently bought a used loader for my tractor and when I put it on it would barely lift it's own weight. I already had the loader controls on my tractor, but after extensive investigating I found that there was an internal plug on my scv valve for an optional something or other. Long story short I either had the option or didn't but whatever the case was there was this plug that had backed out and was sitting loose inside the valve and allowing all of the fluid to bypass. Maybe there is something similar in your case? My tractor is geared so I did not notice a driving problem, also there was no affect on the 3 pt hitch.

 

[intothewoods]

Finally had to give up and let the dealer have at it... unfortunately their tests indicated the HST was bad... and after only 560 hrs.. they've had it almost 2 weeks now saying they've had trouble getting a new unit delivered... not happy..

 

[creekbend]

Finally had to give up and let the dealer have at it... unfortunately their tests indicated the HST was bad... and after only 560 hrs.. they've had it almost 2 weeks now saying they've had trouble getting a new unit delivered... not happy..

Sincerely sorry about your misfortune. Best wishes.

 

[MHarryE]

Finally had to give up and let the dealer have at it... unfortunately their tests indicated the HST was bad... and after only 560 hrs.. they've had it almost 2 weeks now saying they've had trouble getting a new unit delivered... not happy..

Let us know if they are able to tell you if the low grade hydraulic fluid might have contributed to the problem. If I have this right, working fine. Lend to a neighbor. He adds hydraulic fluid but of an inferior grade. Immediately after the tractor begins to have problems.

I have wondered about sharing equipment. When I use a shared disk I use my own cylinder because I do not trust the other person's 30 year old tractor and the hydraulic fluid it contains. By replacing the cylinder when I use the disk I keep my fluid relatively pure except for any contamination that enters the system from connecting and disconnecting my cylinder. Have wondered if that is an unnecessary exchange since we both use Pioneer couplings an it would be easier to hook to his cylinder and go.

 

[intothewoods]

Sorry, been off the forum for awhile.. Dealer wasn't really helpful as to the reason for the early demise of the HST.. although they didn't think the lighter fluid was much of a factor. Although I talked with the person who borrowed it a little more and turns out they were running it in High for everything they did... mowed, tilled, graded.. if I had to put a tag on the problem, I would say that was an issue.. Lesson learned.. don't lend your Precious out to morons...

 

[whistlepig]

Sorry to hear about your HST. I have a B7800 also with 730 hours. I would be pretty upset if I had your problem.

 

[SSdoxie]

Pulling hard in high range will overheat the oil quickly. You can put a lot of "years or hours" wear on HST in short order with extremely hot oil. I have a couple neighors that have hinted or asked obut using my tractor. Told boht of them to let me know a few days in advance of when they need a job done and I will come down and do it for them, but NO ONE drives the tractor but me. Me excuse to them is, insurance won't cover it, but really it is I have too much invested in it to let some inexperienced "idiot" get on it.

 

[whistlepig]

My B7800 has a surge relief on the HST. If I am working in too high of a gear for the work it is doing, like loader work, I can feel this surge relief kick out. It's a slight hesitation and a jerk in forward movement. My owners manual says that this won't hurt the tractor if the surge relief does kicks out. But continued operation with a load that kicks out this surge relief is not recommended.

 

[intothewoods]

Hmmmmm... checked in on this thread again... Whistlepeg, thanks for your comments... I wonder if the surge you're describing is something I have felt occasionally when driving on surface streets going between properties... I drive in high, 2wd at about 2000 rpms to maintain 20-25 mph... I'll be chugging along when I'll feel a brief surge of speed that lasts for a few seconds... it never seems to be running that hot when I do this, but I've always wondered why that little surge kicked in....