B21 problem

MarkV · Nov 6, 2001

I had a problem this weekend that I had not experienced before and thought some of you might be able to shed some light on what happened. After about 5 hours of continues use of the backhoe and loader on my B21 the hydraulics gave out. The backhoe would not respond at all and the loader would rise in about 6” increments and then stop. The tractor temp gauge read normal, hydraulic fluid showed full (best I could tell on that silly yellow dip stick), could not find any leaking, the fluid did not feel abnormally hot and the fluid looked normal. (Changed less than 50 hrs ago and no foaming visible) After about 20 minutes of looking and checking the tractor ran fine for another 2 hrs of work.

Any ideas? Would air in the system do something like this and if so, how would it get there?

MarkV

TWINKLE_TOES · Nov 6, 2001

Mark,
Sorry you're having a problem. I don't have any answers/w3tcompact/icons/frown.gif but I do have a question. When this problem occured was operation of the HST and steering normal or was it affected also?

Al

MarkV · Nov 6, 2001

Al,

Good question and I should have added that in my first post. The steering was fine and the HST was working the best I could tell. I had lowered the backhoe and could not raise it so my test was limited.

If I have a problem I am not sure what it is. After looking things over, checking fluids and reconnecting the lines to the backhoe things worked fine the rest of the day. It was strange and I thought someone might point out something I am missing.

Thanks for your interest.

MarkV

TWINKLE_TOES · Nov 6, 2001

Mark,
I plan a trip to my dealer tomorrow to pick up some mower blades. I will
drop out in the shop and see if the mechanic may have some ideas. One of his is worth more than ten of mine.
Al

TWINKLE_TOES · Nov 6, 2001

Mark,

I pulled out the hydraulic schematics and the only single failure I see that is common to the loader and hoe and not HST and steering is the relief valve. If this is the problem it's no big deal, easy to remove and no big ticket items inside. Perhaps a spring, obstuction in the seat?? This is my best guess other than your idea. I will check with the mechanic tomorrow.

DarinRay · Nov 6, 2001

Let us know how you make out because I have the bigger brother and may someday also run into this....Hopefully not but that's whats great about this site because if you need something you can normally find it out here. /w3tcompact/icons/smile.gif Goodluck with your project.

Darin

allmobile · Nov 7, 2001

One of the quick couplers came disconnected even though they looked connected. I've had this happen many times over the years.

Brian

Anonymous Poster · Nov 7, 2001

Sounds like the drive to the pump may be slipping. We had an instance where the hydraulics worked intermittantly, and when turning the pump by hand ,everything looked OK.

It may be possible that the drive splines just slip on a worn section of the drive, and then make just enough contact to drive again.

The only other possibility I can think of is an interruption to the oil supply. Dirty strainer or similar problem.

MarkV · Nov 7, 2001

Al,

Thanks for taking a look at your service schematics. If the problem continues I will be looking at the relief valve first.

MarkV

MarkV · Nov 7, 2001

Brian,

Your thoughts and experience are always valued so thanks for jumping in. I had thought about the quick connects as we were looking for the problem. I did disconnect and reconnect them and one did feel a little strange. At the time I thought, these things are either hooked up or not and we had been running for a good while so that can’t be it. If you have seen connectors break their seal while still looking connected it may be that simple. I’ll take a closer look this weekend and make sure there isn’t any dirt in there.

MarkV

MarkV · Nov 7, 2001

Darin, If the problem continues, you can bet everyone will know because I'll need your help./w3tcompact/icons/smile.gif

BillK, You are thinking along the same lines I was. EXPENSIVE /w3tcompact/icons/smile.gif Given that we went back to work for a couple of hours and things seemed fine I don't think the drive coupling is slipping. There sure could be some crud in the oil and if the problem reoccurs I will change the oil and filters. Thanks for the ideas.

MarkV

JerryG · Nov 7, 2001

MarkV,
I'm with Brian. I have had the couplers disconnect several times over the years. Most of the time they will still look like they are connected. I just have to disconnect and then reconnect them again. That fixes everything. I have hooked up my backhoe a few times and just knew that they were hooked well. Only too not have any hydraulics. I hope that it's that simple to fix.

Snell · Nov 7, 2001

We have also seen this problem with the quick connects many times. Give all connectors a good cleaning and hopefully the problem will go away for good. Best of luck.

DarinRay · Nov 7, 2001

Boy I'm really starting to like the sounds of this problem's resolution. With this many informed people chiming in with the same possible cause is rather nice knowing that may be the problem, escpecially with that low of hours on your machine and no other indications prior. I shoudln't have to worry about the quick couplers on mine because I seem to break the hoses before anythign else. /w3tcompact/icons/smile.gif not really but seems like when one goes they all want to follow. Darn metal rubbing on hoses anyway.

Darin

MarkV · Nov 7, 2001

You guys sure know how to make a guy feel better./w3tcompact/icons/smile.gif

At the risk of sounding repetitive, this was the first time the hydraulics have ever given a hint of a problem. It always makes me nervous when I hear a new noise or see my trusty Kubota act anyway but normal. I should have more faith./w3tcompact/icons/smile.gif

My B21 has around 750 hrs on it at this point and has been a great machine. There are not that many B21, L35 and L48 owners on the forum but these are wonderful tractors. For those whose needs are more backhoe and loader work you should take a look. As you compare the Kubota TLB series tractors, against their worthy brothers of similar horsepower, there are a number of advantages worth noting. For backhoe use, the tractors are designed for it and have the integrated frame to support it. The hydraulics are also stronger to support the backhoe and loader. The loader strengths are better, they have self-leveling buckets and a slanted hood for better visibility. A four point FOPS is standard and offers great protection from the sun, falling objects or the ultimate OOPS. It is also worth note, all of the extra beef that was added for an industrial machine.

On the other side there are some loses. If a mid PTO is something you need for a mower or snowblower, there is not one offered. The loader is not removable and you lose a few PTO horsepower. The FOPS system stands high for the backhoe, so clearance is not great for low tree branches and the average garage door.

That is the end of my efforts to give Kubota’s TLB series equal time on the forum./w3tcompact/icons/smile.gif I would guess you have figured that I am happy with mine and would recommend that you take a look as you consider different models.

Thanks to all for the help. I am heading to where my tractor lives tomorrow and will check things out. It is great to be able to tap so much experience here on TBN.

MarkV

DarinRay · Nov 7, 2001

I'll second everything MarkV said about the TLB's. The good thing about not hearing or should I say reading much on the TLB series is that there are minimal problems that are experienced with these babies. /w3tcompact/icons/wink.gif

Darin

Now where are the rest of the TLB series owners??

Kubota-monkey · Nov 8, 2001

Proud Kubota TLB series owner here! All of my tractors so far have been Kubota TLB's- A B20 and now L35. So far nothing has gone astray (sp?) with the L35 and never experienced any problems with the B20. These tractors are mechanical phenomena in their ratio of lifting and digging power per size and HP of the tractor. However I am sure all series of Kubotas are great so I do not want to single out any other tractor owners. It would be great if we knew all of the TLB series owners on this site.

The Ben from MA /w3tcompact/icons/cool.gif