http://www.carcraft.com/techarticles...#ixzz3FxvVmJoi

We talked with Tom Lee of Lee Manufacturing who builds racing power steering boxes, and pumps and he prefers the fluid temperature at 180 degrees F, but he also says anything below 250 degrees F is acceptable. What will kill pumps is temperatures exceeding 300 degrees F. Another idea that helps control temperature is to replace the late-model, plastic power steering pump reservoirs with a remote reservoir. Remote reservoirs help reduce heat by reducing the aeration in the oil. We’ve also considered the idea of converting engine radiator automatic transmission cooler fittings to cool the power steering fluid.

Read more: http://www.carcraft.com/techarticles...#ixzz3G35OGOAG

The marine OEM's using stock steering set up will always use a pwr steering cooler for a couple of reasons. Maintaining lower fluid temps help the pwr steering fluid from oxidation due to heat.

Bad or worn out fluid is bad for steering actuator & the pump and high fluid temps also causes steering fade. The main concern with the marine set up is pressures and maintaining them correctly & constant within the system. Mercruiser and Volvo and other Marine OEM's have their testing procedures and values listed as far as pressures.

Using Merc as an example - they sell a pwr steering test gauge kit. Not to go into a story book here about it. The jist is pressure values are - high pressure 1150 to 1250 psi with the test gauge hooked up and low pressure 70 to 125 psi with test gauge hooked correctly. Keeping the fluid at a constant lower temp also helps maintaining these pressure within the power steering set up. That's basically the jist among other reasons.

Fluid oxidation and condensation from wide range heating and cooling cycles is other reasons to help avoid hence the pwr steering cooler inwhich will add longer life of the fluid, seals, pump and the steering actuator (DHB) in marine apps. Again its about maintaining the correct pressures within the complete steering system as well.

That may be their aim, however a stable lubricant at temperature won't necessarily shear and thin out because it's dealing with "higher" temperatures! We need some numbers here or all of this is plain heresay regarding a cooler.

I'm not discrediting the information you provide, however all applications and especially fluids ARE NOT created equal, so you cannot make a blanket statement, Mercury marine, Latham or otherwise, that all apps MUST HAVE a cooler.

It's not 1985 regarding lubrication technology, and unfortunately not too many out there are aware including merc.

Instead of steering coolers I`d rather have Mercury include Drive fluid coolers.
Throwing water on the outside of the drive to cool the oil inside via a drive shower seems like caveman technology to me.

http://33outlaw.zenfolio.com/img/s11...75909298-3.jpg

My "rocket" PS resevoir

Very interesting and got me thinking... For those that verify they do in fact need a cooler, I'm curious if that LS1 ps cooler would work in a freshwater scenario?! Heck they are cheap and abundant vs dropping $100 or more for a new aftermarket unit.

Steering for any app becomes a huge liability for any OEM. One - heat is the down fall just like auto transmissions in our vehicles in which if you maintain your fluid temps you get longevity and the correct pressure thru out the system plus a correctly working transmission. I think they say if you maintain your auto transmission fluid temps (ATF) at 175 F you can double the life of your transmission compared to 225 F constant running temps. Heck that's only 50 degrees difference (lower to double the life).

Anyways Like I said for the Marine apps - pwr steering to work correctly its all about pressures as merc and others list their pressures. If the fluid becomes too hot those pressures fade (lower) and if too hot valving and other parts could fail especially the steering actuator. Merc does not list the temps - they just want to maintain the temps to a certain temp and leave it there constantly so the pressures stay constant along with keeping the pwr steering fluid oxidation & condensation to zero if all possible. Really I know the jist of it and basically that's why for the cooler - heat reduction, maintain a constant fluid temp and to help maintain constant pressures within the steering system for keeping the fluid at a lower constant temp.

After reading 5 pages, I'm glad I have a Hynautic system with no pumps lol

Would life just be so much easier, if we simply ran a steering cooler, like the hundreds of thousands of other boats out there? They are fukin 75 bucks. Issues breaking the cheaper ones, ok, spend a few more bucks and get a sen-dure cooler, they are built much better.

I dont really understand the " I like my steering fluid hot!" idea. Rubber seals are made to work and last, with XXX temperature range. sure, can a modern quality fluid withstand temperature better than a cheaper fluid, yes. But, I dont give a chit what my fluid likes. I want to know what my steering rams, pump seals, helm seals, steering lines, and other parts like.

Are they needed? I dont truly know. Without temp readings its just a guess. In the meantime, I'll just run one like latham recommends. I dont feel like playing engineer, smoking my pumps in a short time, degrading my hydraulic helm seals, hardening my steering lines to the helm, or risking any of that stuff, just to save the 75 bucks, or the minor rigging involved to install the cooler. Just my opinion, but I see no benefit to higher power steering fluid temperatures. I know i will feel better knowing I am providing my pump with cool fluid when I'm in a fun run or poker run and my steering pump is spinning like crazy when I am holding my engines wot for miles and miles. :pacifier:

Your ps oil is too cool and you`re gonna GO slower!!!