2013 CK20s HST chirp when pressing accelerator

[bwestfall]

edit: I changed the title/post to better use proper terminology

Hey everyone,

Still learning about tractors and my new-to-me CK20s I think I have an issue.

When pressing the tractor accelerator, either forward or back, it chirps only on immediate pressure, but after goes away. Constant pressure after the initial chirp works great, and even during the chirp I notice no loss in power or anything. I couldn’t find anything regarding this so apologies of this has been asked before.

The reason I ask if this chirp is a problem is because I (today) at an apple orchard heard a similar size tractor with an HST not have that chirp when moving forward/backward. Makes me think something* is happening during that chirp that shouldn’t be.

Any ideas?

 

[Robin Veerman]

Driving an HST you don’t give it throttle when you want to move. You SET the throttle to about 2000rpm and then leave it there. You only lower the rpm if you’re idling between jobs…

 

[bwestfall]

Driving an HST you don’t give it throttle when you want to move. You SET the throttle to about 2000rpm and then leave it there. You only lower the rpm if you’re idling between jobs…

Aah you’re right I used the wrong terminology. When pressing the accelerator forward/backwards there is a chirp at the start of each press, regardless of the direction. After the initial press it’s gone until I repress it.

 

[Bloodyrun]

My 40 hyd never under 2300 rpms think it's better for engine?

 

[oldnslo]

How quickly are you pressing on the pedals to move forward or reverse?

Is the noise just momentary or there until you get rolling and partially up to speed?

 

[bwestfall]

How quickly are you pressing on the pedals to move forward or reverse?

Is the noise just momentary or there until you get rolling and partially up to speed?

I am pressing at what feels like a natural speed during operation, however testing it last night to really check it happens regardless of the speed I press it. Once the pedal moves past the first inch or so after being pressed the chirp goes away (so it’s momentary), however it’s definitely something caused by the pedal being pressed, not the pedal itself if that makes sense.

 

[Robin Veerman]

My 40 hyd never under 2300 rpms think it's better for engine?

Better for the HST pump…

 

[bwestfall]

Better for the HST pump…

So…maybe this is normal and I have no idea what I’m doing. Raising the RPMs to be where the PTO is at 540, it didn’t chirp which indicates it’s pump based.

The Kubota I saw was a B2650 and the guy operating was moving pallets at the orchard - definitely in low gear and very low RPMs. With it not chirping I figured maybe mine should be/act similarly at low RPMs as well, but following other’s advice about raising them and testing it works and feels as intended - without the chirp.

 

[oldnslo]

Kioti may have added a neutral range increasing valve to reduce or eliminate creep while pedals are in neutral position. Chirp could be these valves closing. Does it accelerate from dead stop nice and smooth or is there a slight jerk when it first starts to move? If slight jerk that would also point towards neutral range increase valves.

 

[bwestfall]

Kioti may have added a neutral range increasing valve to reduce or eliminate creep while pedals are in neutral position. Chirp could be these valves closing. Does it accelerate from dead stop nice and smooth or is there a slight jerk when it first starts to move? If slight jerk that would also point towards neutral range increase valves.

It’s smoother the higher RPM the tractor is at. When it’s lower and the petal chirps it does jerk somewhat at first during the chirp, and then is normal after that as long as I keep the pedal pressed.