Hydrostat adjustment

[jbid62]

I’ve got a Branson 4720H that has had a problem with the hydrostat since it was almost new that no one has been able to solve. When I am traveling forward and let off the forward pedal, the tractor continues to creep forward until you lightly touch the reverse pedal. Same thing for reverse, if you are traveling in reverse and let off the pedal the tractor continues to creep in reverse until you tap the forward pedal. Not only does it make it difficult to do some loader operations, it is also quite dangerous!
There are adjustments you can make to correct one or the other and I’ve had the dealer and another mechanic (as well as myself) work on it to no avail.

Has anyone else had this problem? If so, have you found a fix?

 

[Cougsfan]

Mine has also done that since new. (When creeping, having to push the opposite pedal to stop it). It is more pronounced in low range. Also when driving along the pedal is very slow to come fully up when you remove your foot from the pedal. That tendency is more pronounced in high range. I have learned to live with these characteristics so it doesn't bother me much.

Another odd thing is that if you are buzzing along using the cruise control and disengage the cruise control (by touching the brakes or pushing the cruise control button); the hydrostat pedal suddenly jumps fully up, the tractor comes to a screeching halt, almost throwing me through the windshield. I have also conditioned myself to keep my foot on hydrostat pedal when disengaging the cruise control.

I have also conditioned myself, when starting from a stop (particularly in high range) to push the pedal ever so lightly, like I have an egg between my foot and the pedal that I don't want to crush. If you push the pedal too hard, the pedal goes down even further on its own, the tractor lurches forward and stalls the engine unless it has a lot of throttle.

Again, I quickly got use to all these characteristics and they just don't bother me. It is part of learning the personality of your tractor. I do fine work with positioning of the tractor all the time and I don't really find it to be a handicap or dangerous. But if some one else gets in my tractor to drive it, they may find these hydrostat characteristics a little annoying, depending on the person.

One thing I do like to do when doing fine positioning like attaching implements (on any tractor, not just my Branson) is to keep the emergency brake 3/4 engaged while positioning so as to stop any hydrostat creep or to prevent the tractor from rolling either direction via gravity. I can lightly push the hydrostat pedal when the emergency brake is on and move only a fraction of an inch very safely and precise.

I have talked to my dealer about these characteristics. He said that is just how the earlier 4720 series hydrostats work, but the newer ones are much less that way. Mine was made in 2016. How old is your 4720?

 

[ning]

My 3520h does the creeping thing though I did my best to adjust it with the rears up in the air (I'm and idiot and did my first attempts at adjustment on the ground - nothing bad happened but use your imagination at what could have happened!). It's a very minor creep; as others noted it's more obvious in low range (probably not enough torque to move it in high range).

I have a different problem with cruise which I think is completely unrelated to the creep - if I use cruise (which I mainly use when going up my "long" hill at speed in range 2 (out of 3) which I deliberately do to cook the DPF), when I turn off cruise it pretty much doesn't disengage much - rpm's go from like 2500 to 2100 and just stick there. A very mild tap on the the reverse pedal takes it off completely; I tend to avoid cruise because of this but for me it's a minor nuisance as I don't actually need it for anything.

 

[ericm979]

There's a pretty complex linkage for the pedals under the floorboards. I'd start by making sure that's all clean and lubricated where needed. I should probably do that with mine just on general principles.

When I'm moving along in range 2 with a lot of HST pedal and back off, if I'm going down hill the HST does not return to neutral like it does on flat ground. If I'm going up hill though it'll come to a stop.

 

[ning]

There's a pretty complex linkage for the pedals under the floorboards. I'd start by making sure that's all clean and lubricated where needed. I should probably do that with mine just on general principles.

When I'm moving along in range 2 with a lot of HST pedal and back off, if I'm going down hill the HST does not return to neutral like it does on flat ground. If I'm going up hill though it'll come to a stop.

When I first got my tractor, it would almost skid to a stop when I let off the pedal going downhill (without hitting brakes or reverse). Now, it'll slow to a stop (if I wasn't using the cruise) on flat or uphill; I definitely have to use the brakes going downhill to stop. When I get some time, I'll remove the cruise magnet completely and see how things work, and then figure out why it's not properly disengaging.

 

[FastEddieR]

I've gone through 3 pedal return springs in 4 years. They all broke. This latest one has been in place for almost 2 years now and is not quite as stiff as the previous ones, it doesn't snap the pedals back up but they do return to "neutral" fairly smoothly. When the transmission is still cold it tends to creep either forward or backward like the OP says, usually just a slight push on the opposite pedal stops it. When it's warmed up it doesn't happen as often. I did have to adjust the cam roller thingy a little bit - back when I first got the tractor...it's as neutral as it can be now without using a micrometer and other super special measuring tools LOL

 

[Slowpoke Slim]

When mine developed a creep, my dealer was able to adjust it back out. I think that was at about year 1? So far it hasn't come back. I haven't broken a return spring either. So far, so good.

 

[jbid62]

Thanks for your help guys, sounds like a fairly common problem. I spent a couple of hours cleaning and adjusting it today, but it still creeps in both directions, maybe not as badly though. I’ll see how it is when it’s warmed up and maybe try a stiffer spring if I can find one.

 

[Branson Bob]

Thanks for your help guys, sounds like a fairly common problem. I spent a couple of hours cleaning and adjusting it today, but it still creeps in both directions, maybe not as badly though. I’ll see how it is when it’s warmed up and maybe try a stiffer spring if I can find one.

Do you ever have a situation where you have to fine tune the pedal position into "neutral" in order to start the tractor?

 

[FastEddieR]

Thanks for your help guys, sounds like a fairly common problem. I spent a couple of hours cleaning and adjusting it today, but it still creeps in both directions, maybe not as badly though. I’ll see how it is when it’s warmed up and maybe try a stiffer spring if I can find one.

the spring is hooked to a long tensioner screw on my 4720H, maybe you can tighten it up some. could be as simple as that, since it creeps both directions it sounds to me like the spring isn't tight enough