hydrostatic problems

Les walter · Nov 6, 2006

I'm looking for some guidance in getting B7100 HST moving smooothly again. It does not respond to forward or reverse well anymore...before I take it apart, I believe I should take some pressure readings. I've got 3000 hours on this rig. It does not look like an easy job as the tractor has to come apart in the middle. I was thinking of rebuilding the hydro part of the transmission

les

alchemysa · Nov 6, 2006

Les. I had a similar problem. Read my message called 'B1550 Hydrostatic Trans whine'. (Its on about page 3). Do you also get a nasty whining noise too? My problem was that no oil was getting to the trans. Removing and cleaning the wire mesh strainer at the oil sump was a simple and cheap fix. When was it checked last?

Les walter · Nov 7, 2006

yes, whine is loud!..... screen checked I don't know when. Will check it tomorrow

thanks

alchemysa · Nov 7, 2006

Les walter said:
yes, whine is loud!..... screen checked I don't know when. Will check it tomorrow

thanks

There are two screens. On mine the one on the left supplies oil to the trans. The one on the right supplies oil to the loader etc. I think yours would be the same.
Check out the site below for free parts books. I can see a few for the 7100. They are priceless.
http://www.mediamax.com/kubota4you

alchemysa · Nov 7, 2006

Les walter said:
Will check it tomorrow

If you check it you'll have to drain the oil, so you may as well be prepared to change it. (There's a drain plug on the bottom of the hydro trans.). Heres a hint. Don't overestimate how much oil you'll need. My book said I'd need about 15 litres all together including hydraulics, but I reckon I barely used 10 (about 10 quarts), so there must be a lot of oil sitting in places I didnt drain. You might only need a couple of gallons. And theres probably an O-ring on each side of the circular oil coupling so be careful you don't lose them.

alchemysa · Nov 7, 2006

alchemysa said:
(There's a drain plug on the bottom of the hydro trans.)

Correction! The drain plug is on the bottom of the mid PTO.

Egon · Nov 7, 2006

I think there are three drains for the hydro. one on the midmount PTO, the other two on each side beside and below the rear wheels.

Have you checked the linkage and also made sure the centering roller is running on the v notch and has not slipped off beside it.

Les walter · Nov 7, 2006

Good! I've got a couple of things to look at as soon as it stops raining here in Washington.....I don't suspect that the linkage is off but I will check the alignment .....it does creep sometimes when in "neutral"
Thanks to Australia and Canada!

les

FlatHillFarm · Nov 7, 2006

Hello all.

I just bought a brand new L3400 with a HST in October and had it delivered a week or so ago. One thing I noticed right away the first time I drove it was that the HST whines pretty loudly. Its significantly louder than other Kubota tractors I have seen in action, and the further you press the HST pedal down, the louder it gets. I am having the dealer service guy come out and look at it to tell me if its normal, but I am worried.

I have read and talked to tractor owners that have had HST transmissions go forever without a problem, and then I read posts where people have had nothing but trouble from their HST transmissions. So it seems to me that they are either fabulous performers or hopeless lemons. I love my tractor and I hope it lasts forever, so I hope it fits in the fabuluous performer category

I will post what the service guy says when he looks at it.

Egon · Nov 8, 2006

I forgot to mention another adjustment for the hydro and creep. There is a wobble plate type screw on the right hand side of the hydro that can be used to eliminate or adjust the centering feater of the hyro static. There is a hole in the frame through which you access this adjustment.