Kubota B7200HST

[Wrighty]

Hi this is my first post on this forum and my Kubota B7200HST tractor has problems driving up hills,when the forward pedal is pressed down the pedal just shutters and has a loss of power.

I thought it was the clutch but we have put a new one in and it still has the same problems.
I have also changed all the oil and filters on the machine.

Any thoughts on what it might be?

 

[dusty-t]

Hey Wrighty. I had almost the same problem with a b7200 hst, loss of power on hills, but no shudderring. I replaced the clutch also, but that was because the clutch was pooched. It had always had low power to the hydrostat but it always did what I needed it to do. After I replaced the clutch I took it to kubota and they said the hydrostat was pooched. But it had been like this for the four years I had owned it and never got any worse. Anyway I ran a can of tranny flush through it, changed the fluid and filter and it made a big difference. I don't think it was as good as it should have been, but it was a LOT stronger. For my b7200 I think it was just sludge from twenty years of poor or no maintenance. The shudder in yours seems to say relief valve in the hydrostat unit to me. But there is a ton of experience on this forum.Wait to get a few more opinions before you do any rippin and tearin on your tractor. Good luck and keep us posted. dusty..

 

[eserv]

Does it work ok in reverse? If so it might be the High pressure relief valve. What oil are you running in it? there is a suction screen on the charge circuit on those tractors. look for a larger line going from up under the front of the hydro back to the right side of the transmission. The big bolt in the "banjo" end of that line has a screen on it. It can cause a pulsing, power lose situation if it's plugged . If it is the high pressure relief valves you can remove them and put them in the opposite positions to see if the problem goes to the other dirrection. If the pump and /or motor are failing the hydro should be getting hot. By the way, the further down you push the pedal the less "power" you have (but more speed)! It is not like the gas pedal on your car! This concept is the first thing we have to impress upon our RTV customers!
Ed

 

[Wrighty]

Hi all,Thanks for the usefull info i have been trying to locate where the screen was, found it thanks Ed and it seems ok have cleaned it and put it back in.The machine works fine in reverse the problem is the machine struggles getting up small inclines even when you ease the peddle down it shutters.
The oil that we have been using is SAE 10W30 is this ok?
I am just sourcing some tranny flush and now have a parts breakdown of the hydrostat unit but it dosen't show where it's bolted on at,this might be a silly question but where is the hydrostat unit?

 

[dusty-t]

First I hope that 10w30 is going in the engine and not the hydrostat.Under the seat on the right hand side is a dipstick for checking the hydro fluid.The tractor uses the same oil for the hydraulics and the hydrostat. On the left side under the seat should be a fill plug. this is where you put the hydraulic oil.As far as the tranny flush I don't think it will do anything for you. I think Ed is right it is a malfunctioning relief valve. I don't think it will hurt anything but but it is expensive because you have change the fluid and filter after you use the flush.Do you have a work shop manual, if not get one, you are going to need it.By the way Ed is a Kubota tech ,chances are he is right. Like I said don't go rippin and tearing untill you have all the info. There is a steel cover between the seat and the dash, under it is the hydrostat unit and filter. If you haven't changed that filter it may be dirty, but again if it was that would affect both forward and reverse.I'm thinking that relief valve should be your first job then change fluid with Kubota UDT and the filter. The workshop manual has all the procedures to do this. kubotabooks.com maybe? Or service dept Vic or Mr K. or Eserv may be able to help you out with that. Good luck and keep posting.The only stupid Question is the one you don't ask.I know I have done a lot of not asking.

 

[Wrighty]

Thanks Dusty,The tractor is used on a golf course and i have taken over as the manager in the last year the oil they had been putting in the Transmission is John Deere Hy-Gard 10W-30 so i will look at an equivalent to Kubota UDT if this is wrong.
I had already changed the transmission/Hydraulic oil and filter to see if it made any difference.
I will purchase a workshop manual and just wait for more opinions on the matter.
Cheers

 

[dusty-t]

Chances are the Hygard is fine but check it out. I thought you meant 10w30 engine oil. If it is that relief valve it should be a fairly simple fix.

 

[dusty-t]

I wouldn't say its a nightmare. I enjoy this stuff.I would still like to rip into a hydro unit. But I would like to start with a dead horse, You know some thing that some one doesn't have a few thousand invested in it.That way if I screw it up I'm only out a thousand or fifteen hundred bucks. Not that I can afford that either but that is how much I like this stuff.I am an amature and intend to stay that way. It took me a month to do a clutch. And there is a reason for that. I am 53? and forcebly retired I'm broke but I am havin the time of my life.Anyway hang in there Wrighty, Keep us posted.

 

[Pat Pending]

I have a B7200HST that I drove for the first time today. Bought it with a blown engine (gear case contents scrambled), invested about $200 and now I have it running (poorly, but that's another story).

Anyway, I too am having HST problems but I think it's just low fluid level (certainly some was lost during the rebuild which someone else initiated).

The symptoms are a growling noise going both forward and backward but it got much worse after driving for about 5 minutes. Naturally I took it very easy at that point. I did raise and lower the loader some and I suspect that this exercise may have moved fluid into the cylinders, depriving the HST. I started the tractor to park it about 15 minutes later and the HST performed about as it had originally.

I found the dipstick but am very unsure where the level is. The fluid appears very clear so it's hard to gauge where it gets to on the dipstick. I hope what I'm seeing is more than residue dripping onto the dipstick as I replace and remove it! Anyway, the dipstick is short and has a line in the middle of it. Does that line mean full, add or what?

Ok, so if I can figure out that I do have enough fluid, my next guess is the filter and then that screen by the tranny?