HELP! Did I do something really bad to my B7300?

[Climber]

This weekend, I decided to perform some routine maintenance on my B7300HSD. I changed the engine oil and filter, transmission oil and filter, front axle oil, fuel filter and air filter.

I drained the transmission oil from both drains plugs in the rear and the one in the front transmission case. Then, I replaced the filter. After that, I pulled off the transmission strainer. I cleaned off the filings on it, and replaced it. I then refilled the system with Kubota brand Super UDT.

Following the service, I followed the manual’s instructions, and I ran the tractor at about 1500 RPMs for 10+ minutes. Then I decided to take it for a spin. I climbed on, and pulled back on the hydraulic control to raise the 3PH. To my dismay, NOTHING happened. It did not move an inch. Then, I stepped on the forward pedal. The tractor whined, and moved forward, but it felt like I had the brake on, only I didn’t. Moving back was the same. I only moved it about 4 feet forward, and 4 feet back.

I shut it off, and I got kind of sick feeling, but I had to quit for the day. I thought about it some today, and I realized that the transmission fluid was a little higher than the full mark on the dipstick. Today, I drained about a quart, to get it back between the lines. Then I tried again, with the same results.

HELP!!! What could I have done? I followed the procedure in the manual to the letter! I’m rather worried about this!

Thanks,

--Chris

 

[Junkman]

I am a firm believer that if it worked before the change, it should work the same after wards. Having said that, I would go back and check everything that you have done. Possibly when you re installed the filter screen, you might have something reversed? Having no experience with the Hydro, I don't even know if this is a possibility. The one thing that I do know is that the Hydro is a very strong unit and I doubt that you have done harm to it. Also, since you drained everything, did you cycle the loader to purge any air out of the system, etc. If all else fails, you can call the tech service guys at Kubota. I have asked them many questions since buying my tractor and they have always come through with the answer even if it takes a day to find out. You can find the number on the back of your operators manual.
Just re read your post...... if the Hydro (charge pump) whined, then I am inclined to believe that it is air bound and that it needs to have the air worked out of it by working the loader..... that is, if you have one... If not, then try to work it out with the 3 point hitch control. I am far from the expert here, but I have some experience with charge pumps and this is usually what happens..

 

[jinman]

Are you sure you got all the filters in the right spot? Changing so many filters at once could have led to your getting a couple of them mixed up. You might even remove them to look for evidence of blockage and compare them to the old filter you removed. If one of the filters is the wrong one, you could be experiencing blockage or very high restriction. The gasket seal on a filter could actually be blocking flow. Look for foreign material or plastic that might inadvertently have gotten into the filters. It's a long shot, but these types of problems usually end up being somewhere you have just done work. Are you sure you filled all the reservoirs you drained? I think you'll find the problem if you recheck all your steps. Good luck.

 

[chim]

PLEASE don't take this as an insult to your intelligence. Sometimes odd things happen. Was there any plastic protection on the business ends of the filters that could be blocking the flow that didn't get removed in the heat of the battle?....................chim

 

[Climber]

Junkman,

Well, I went back and double checked everything but nothing really jumped out. I am inclined to believe the air theory myself, but I have no idea how to bleed it out of the system. The manual does not list any such procedure. I do not have a FEL (unfortunately). I did try to raise the 3PH a few times manually, but no change. The control still won't budge the 3PH. I guess it's time to call Kubota tomorrow.

Thanks for the reply, and keep me posted if anything else comes to mind.

--Chris

 

[Climber]

Well, I thought your filter blockage idea was certainly a good one.

First, I double-checked the part number of the old filter vs the new filter. They matched. The filters are all different sizes, so I don't think it's possible to mix up an engine oil filter and a transmission oil filter.

Then, I pulled the new transmission filter off, and put the old one back on. No change in behavior.

Finally, I decided to pull the transmission strainer off, and make sure it is not blocked. Other than making quite a mess, I had no success.

I guess I'll call Kubota tomorrow. I hope they can help. If anybody has any other ideas, they are most appreciated!

Thanks,

--Chris

 

[Climber]

Good idea. I certainly did not take it as an insult. Stranger things have happened. Unfortunately, that was not the problem. I pulled the new transmission filter off, and put the old one back. It still does not work.

 

[Junkman]

Kubota West........ 209-931-5051
Kubota Central..... 817-571-0900
Kubota Northern....614-492-1100
Kubota Southeast..770-995-8855

Pick the one that is closest to you or one that isn't around lunch time when you call. I have found that between 12 - 2 it is hard to get a hold of someone. The 9 - 10 slot is also bad for some reason. If you don't get a hold of anyone in tech service, then just leave your name and tell them what the problem is and they will call you back. I always give them the telephone number at the beginning of the message and also at the end. Make it easy on them and speak slowly, because if your "accent" from your part of the country is different than theirs, it can be difficult to communicate. We all speak English, but from the various regions of the country, we all sound differant...... Also, give them the model and serial number of the machine.....

 

[mahlers]

I'm totally new to this forum, and don't yet have a tractor to call mine, but I think the hydro trannys in these units work the same as most other automatics. From what you've described, it sounds like the torque converter in your transmission is full of air. Do you know how many quarts came out, and how many you put in? If there's air in the system, and you put the manufacturer's required fill in it, you'll notice that it looks like you overfilled it by a long way.

There should be a line to the tranny cooler that you can open up and bleed out the air. Generally, the tranny will pull fluid out of the pan, pass it through the strainer and then the filter, and then put it into the converter. After that, when it is nice and hot, it will pass out to the tranny cooler and then go straight back into the pan. I would guess that there's a clamp on a flared metal tube-to-rubber hose junction right before the cooler. If you pop that clamp and let it run for a few seconds, you'll bleed all the air out. Run it at low RPM's until you see the fluid coming out with no foam.

Again, I might be totally out of my tree on this one because I don't normally work on tractors - but something tells me that they aren't all that different than the other gazillion fluid-based power transmissions out there. Everyone please forgive me if I'm totally wrong.

Martin

 

[Junkman]

The hydro unit on a tractor is very different than a transmission on a car... If you would like to read more about tractor hydrostatic drive, please go to this page hydrostatic transmissions under the Maintenance and Trouble shooting Heading. If you would like more information about hydraulics in general, then go to the home page .... click here...... This particular site has some very good information and theory.... sometimes more than you want to know......