Zero-turn follies

Last Sunday (May 25, 2008) I mowed our south wing and the Back 40 with our dreaded zero-turn.
One of the advantages of a zero-turn is that you can cut sharply around a bush.
But it wasn’t working — at least not at first, which was the south wing.
Push the right lever, and stop the left lever, which is supposed to turn it sharply left, and it would go a foot or two, and then do nothing.
I also mow a shallow roadside drainage swale, and it wouldn’t go straight; doing so requires pushing the right lever to offset the left side of the swale.
I stopped after the south wing before attacking the Back 40, and then continued — and on the Back 40 it mowed like it always has, cutting sharply left around the bushes.
So yesterday (Tuesday, May 27, 2008) I went to the guy who sold me the zero-turn three years ago to pick his brain.
“I have a hunch them twin hydro-static units in that mower have fluid-levels to maintain, and the right one may be low.”
“If one was low, you’d see a leak,” he said.
“What if it was a slow leak; it is three years old,” I said.
“Nope,” he said. “If it leaks it would be a fast leak. You’d see a puddle. And if the hydro-static unit was low, it wouldn’t work at all. You’d hear a racket.”
“Okay, lemme tell ya what happened,” I said. “Push the right handle to turn left, and it would go about a foot, and then nothing.”
“Then after sitting off a few minutes, I mowed the Back 40 and nothing was wrong.”
“Sounds like a fluke to me.”
Whoa! Say “fluke” to The Keed and I wonder about that — everything (supposedly) has a rational reason; except after driving ‘pyooters I’ve come to expect “flukes.”
“What if the right dump-valve had been tripped?”
“Wait a minute! Define ‘dump-valve.’”
There are two rods at the back of your mower, that trip the internal dump-valves in the hydro-static units so ya can move the mower. If one had been tripped, that hydro-static unit won’t do anything.”
“But if a dump-valve had been tripped, I wouldn’t have been going a foot.”
“Yes you would. That unit still works a little even dumped.”
“I don’t want to force you to pick that thing up if I can fix it myself.”
“If I were you, I’d try it again and then call me if it gives ya problems. Mighta been a fluke.”

RE: “South wing and the Back 40.....” —We have about 4&1/2 acres, comprised of four mowing areas: the front yard (small), the north and south wings (large side-yards), and the “Back 40,” a huge backyard field.

Our “zero-turn” is our 48-inch Husqvarna riding-mower; “zero-turn” because it’s a special design with separate drives to each drive-wheel, so it can be spun on a dime. “Zero-turns” are becoming the norm, because they cut mowing time in half compared to a lawn-tractor, which has to be set up for each mowing-pass. “Dreaded zero-turn” because my macho, loudmouthed brother-from-Boston, the ad-hominem king, who noisily badmouths everything I do or say, claims I am incapable of driving a zero-turn without mistakenly mowing trees, flowers, and taking it into the ditch — which is mere noise.