On my 99 Fastech 353 with Latham external steering we discovered this spring that the power steering reservoir on top of the HP 500 setup was completely empty and I saw some fluid down in the bilge. It was not empty when we winterized the boat. The motors were winterized properly and we have had no other problems related to winterization or lines freezing. Any suggestions on what might be the cause of this? Thanks

Fill it up. Fire it up. Look for the leak...

Yep, just as soon as I can find someone willing to stand on their head in the engine compartment with the motors running.

You can buy oil dye at any auto parts store, and with just a cheap UV flashlight it's very obvious where it's coming from.

I may have to pull the exhaust manifolds off the motor you can't really see underneath at all it's very tight. My suspicion is that it's one of the lines going to the cooler or the cooler itself but you can't see it so I was looking for some suggestions from somebody who's gone through this before with an HP 500 setup.

Leak can be anywhere. The dye is a good suggestion. A cheap UV ble/black light to help see the dye is suggested. While your in the parts store you can get a cheap telescoping mirror that may also help you.

Or just hit amazon instead of parts store.

The dye 'glows' so looking for it when dark in engine compartment makes it easier.

I use my cell phone camera taped to a stick

could be as simple as a loose fitting. Give them all a quick check, fill it up, then look for leaks

Get in there with a paper towel and start wiping things down starting with the reservoir on down until you start getting fluid on the towel.

It may be leaking anywhere. It took months to leak out, so its not going to be a huge leak...its going to appear to be just seeping out from somewhere.

it was a crack in the ps pump housing neck that caused the leak. Cound have been a weak weld or I leaned on it when we were winterizing. The pump is crazy expensive also, the new part # 8m0084520 list price from Merc is something like $450. I guess its 100 for the pump and 350 for the blue paint...