a few B7500HSD questions

moonz · May 1, 2002

hi all,

I just got a new B7500HSD with RCK60-24B mowerdeck last week, and I have a couple of questions...I'm new to tractors in general, so please bare with me...occasionally, then I press down the forward pedal on this tractor the hydrostatic tranny kinda jerks into motion...I can't notice any lack of power or anything, and when I'm giving it constant forward pedal pressure it runs out beautifully, but if I slow down, and then hit the forward pedal sort of abruptly, it will sometimes kinda lurch forward...it may have something to do with being on a hill?...or tying to accelerate when I'm turning?...I don't know...my little riding mower with hydrostat doesn't do this, so it's got me wondering.

I've also noticed that the mowerdeck does not stay in the "uppermost" position more than about 20 to 30 minutes...if I shut off the tractor with the mowerdeck in the "uppermost" position, and then come back an hour later the deck will have lowered to the ground...since this is the first piece of equipment I've ever owned with hydraulics I'm at a loss to know what is normal.

Any help would be greatly appreciated.

Thankz!

TresCrows · May 1, 2002

I think what you notice is normal operation. You will find that the lurching is less pronounced in low range and I think also when the engine is operated at near PTO speed.
Yep, your mower deck will slowly fall after you stop the engine, unlike the BX it does not have a lock up position but you could install the pins provided for this purpose.
Your machine is also very new, have fun, enjoy. J

snowman · May 1, 2002

In addition to what Trescrows said regarding the drifting lower of the mower deck (3 pt hitch), there's a black knob under your seat. If you raise the deck up, then turn the knob, that will shut off the hydraulic valves (or something to that effect) and it will not drift at all. You don't want to use this knob if it's only for a short period of time, as it's a pain to turn.

kubmech · May 1, 2002

Moonz, the hst pedal "jerk" is normal. What you are feeling is the neutral valves closing and applying full pressure to the hydro motor. If it really bothers you, you can have the spring in the neutral valves shortened by about one ring. This will settle it down some but not completey. Just keep in mind that it is perfectly normal and will not cause any damage or problems the way it is. The mower drifting to the ground in 20-30 minutes seems a little excessive to me, and that, I would probably have checked out. Hyd. systems do have some natural leakage but that one sounds kind of quick to me.

chrisjbell · May 1, 2002

I have a B7300HST, and my deck won't drift down for quite some time. I've had it in the raised position overnight before (by accident), and in that amount of time it sinks to the ground. But when I have the mower height set the way I want it and I need to hop off the tractor for a while I'll leave it "as-is" and it stays up for much more than 20-30 min. Since it is a new tractor, I'd have your dealer look at it.

...Chris

medfieldtractor · May 1, 2002

I agree that 20-30 minutes seems a bit fast for the MMM to sink all the way to the ground. The MMM on my B7500HSD slowly sinks also, but probably only a franction of an inch in 20-30 minutes. As others have mentioned, I think it would take overnight for my deck to sink all the way to the ground from the top-most position. Since your tractor is brand new - - I would have the dealer check it out. Congratulations on your new Kubota, by the way! I hope you enjoy many happy days on your beautiful new machine!

moonz · May 1, 2002

hey...much thanks to all who responded to my post.

I may have been a bit off on the estimation of time it takes for my mowerdeck to fall to the ground...never actually timed it...it may take longer than I suggested.

I'm extremely relieved that what I described in my post turns out to be just normal B7500 manifestations. Wasn't looking forward to the dealer guyz manhandling my new tractor again, so soon.

This is a great discussuion group for peole like me, with little tractor knowledge...I'm very happy to have found it.

Chalk up one more for the good ole internet...the greatest vessel of knowledge man has ever devised!

cheers to all fellow Kubota fanz,

-moonz-