Is it a must to run with a power steering cooler? I think power steering fluid has a boiling point somewhere above 400 F.

Has anyone ever run with out a power steering cooler?

mercury would not use cooler if they did not need to, easy way to reduce costs. the pump creates heat thats got to go somewhere.

Why would you WANT to omit the cooler?
You can plumb them in most anywhere if you have space problems.

FWIW, the pumps are automotive based and cars usually at least have a loop cooler. If it bugs you, go full manual

I do not have a PS cooler on my full hyd system and have never had an issue. It was like that when I bought it.

Ran all last season without one, no issues so far - Full Hyd.

Get a tranny cooler. Drops the temp by 80-100 degrees.
$150

Full hydraulic is a different beast than hydraulic assist.
Assist has a much smaller volume of fluid to heat up, and less distance to bleed heat into the "environment". Also, the bypass pressure on a full hydraulic is usually set lower than the standard popoff on the pump.

MC

So to jump in here if I may? I had the idea to take the PS cooler out of the system on the stbd engine because I think it is causing a restriction to the engine. I am not having any over heating issues but the pressures are lower on that engine. My plan was to plumb the PS cooler off of the drive pick up so water would flow only while moving. Any thoughts?