cooling fan on hydro tranny

The fan has a centre depression that collects grass but that little bit of grass doesn't impede air flow. If the entire area is allowed to build up incuding the cooling fins on the hydro, then that can be detrimental.

I don't advise using a pressure washer at all on that area. Some people use a leaf blower to clear dry grass away from the top of the deck and hydro. Not having a leaf blower, I use a broom, my hand, and sometimes compressed air.

I use a leaf blower everytime after I mow or do leaf pick-up patrol. You won't believe how much debris gets dislodged from the underside of the tractor.

If the cooling fan or tranny housing gets clogged with debris, it can overheat the tranny oil and cause severe damage. Don't use water (especially high pressure water) as this can find its way into your tranny through breather holes and cause damage as well.