Hey guys, in advance I would like to preface that this is a Yanmar SC2450 (SC2400) which from my not-to-educated SCUT knowledge is very similar to the 1025R.
I have searched high and low on the cub and Yannie sites with no luck, I have studied the technical manual for the machine and nothing really stands out, hence me asking hear. Plus I imagine many of these HST's operate similiarly anyhow. If not, or this is an unacceptable post, please move or delete, my apologies.
Here's what I got going on. Since I bought the 2010 SC2450 with 30hrs on it, when I work it hard (e.g box scraper, heavy FEL work), the brake function would start to diminish. When releasing the forward (or rearward) pedal direction it would feel roll and not stop. Sometimes the brake would slowly engage, other times not at all. I never really cared to much since at that point I'd been pushing it to the limits for a while and it was time to quit anyway. The next day it was back to normal, forward/reverse/brake all HST working normal.
Up until recently after a decent hard working, it did not resolve itself after the cold soak. Now when I let off the pedal (mainly going forward but sometimes reverse) there is no braking function. Not all the time but more often than not. Also, now with that happening, when changing directions (with the rocker-style pedal) it engages harshly into forward from reverse. E.g. If I back up rather quickly and let off, it normally slows down in reverse, but rocking the pedal to forward there will be a noticeable change in the resistance (lighter) felt in the pedal and while continuing to depress it will suddenly very harshly engage forward range. Sometime so harshly that it pops the high/low lever out of low into high range.
From what I can see, all of the linkage is moving freely and the damper is returning it to neutral position every time. Even though the "arm" connected to the shaft into the HST returns to the neutral position and moves forward and rearward with the pedal movement, the above characteristics are present. It does not appear that the damper is asking up, it always smoothly returns to neutral and the lever always moves according the input on the pedal. If I am gentle and move the pedal slowly, the brake works and forward and rearward engagements are smooth (normal) but if I start to move more quickly (e.g nothing more than normal use moving dirt around, cutting the lawn etc.) the harsh engagements and lack of braking return. It looks as if something must be going on with whatever is connected to that shaft into the HST (swashplate?). I have never had a HST apart so I am not sure exactly how the swashplate assembly works and if this could be simply something sticking or a worn/failed seal or broken spring, etc.
Any words of wisdom is greatly appreciated! cheers!