HST Pedal Damper

   / HST Pedal Damper #1  

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Joined
Nov 22, 2008
Messages
2,917
Location
Ontario, Canada
Tractor
Kubota B2620
Went to look at a friends B2620 this weekend. He bought it used and the hydro pedals do not neutral (center.) Everything moves freely. So I removed that HST damper, the thing that looks like a shock with the rubber boot over it. (part # 6C350-4335-0
Is this part supposed to center? When I push his in, it stays in. When pulled out, it stays out.

It's all I can see that would be holding the pedal applied, unless there is an internal issue?

The other rod for the safety switch isn't holding it.

Thanks.
 
   / HST Pedal Damper #2  
I'm not sure on that tractor but on my BX, a spring returns it to nuetral. On my BX the damper got kind of sticky and I just disconnected it. Its a little more jerky but its better than having it stick when you let off the pedal.
 
   / HST Pedal Damper #3  
Take it apart and check out the inside see if the spring is broke or just clogged up.
 
   / HST Pedal Damper #4  
There is a separate spring (not part of the damper), which is what recenters the treadle. All the damper does is to slow the rate at which it returns to center. The damper should move freely, but not move by itself -- it takes some external force or spring to move it.

You can download a parts diagram from Messicks to see the whole mechanism attached to the treadle. The spring is usually located in a different spot than the damper, but the two are linked by the mechanism to work together. The spring is a separate item and easy to identify.
 
   / HST Pedal Damper
  • Thread Starter
#5  
OK thanks everyone. I did see a spring in there, but looks like I'll have to take it all apart to access it. I'll have to check it and see if it's weak or broke.
 
   / HST Pedal Damper #6  
Typically what fails is the bearing that rides on the HST arm. Other than cutting a big chunk of the clutch housing out and welding it back in afterwards, this repair requires splitting the tractor.
 
   / HST Pedal Damper
  • Thread Starter
#7  
The pedals move nice and freely. Just won't center. So I can't see it being anything wore.

My friend lives 7 hours away and I'm not down there any more.....so I'll just have to give him ideas as to what to look for now.
 
   / HST Pedal Damper #8  
Check all the linkage for wear as well, when I repaired one on my last tractor when it got to about 2000 hrs on it I found the bushings in the linkage were warn enough when the damper centered it didn't move the lever in the tran enough to center it. Once I cleaned up the damper and got it working well and fixed the linkage all was well for many more years.
 
   / HST Pedal Damper
  • Thread Starter
#9  
OK, thanks. It only has 700 hours on it, but he bought it off someone that used it commercial and it had a salt spreader with it. So it looks a lot older than it is.
 
 
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