Have a '99 walk behind 52" with Kohler 22 horse. I bought used in 2001 and have kept it up better than most. Guessing about 900 hours on it (meter went out at 800). I'm guessing the right pump is shot as it got slow, sticky, then just plain quit moving the right wheel. An aftermarket pump is $500 ish. What is this pump connected too? Is there another $300 worth of stuff that it is tied to that might need replaced? Advice on repair, where to purchase parts, where to list if I part out etc. appreciated.