Hello all.

Does anyone know if the power steering cooler is needed on a mayfair, twin cylinder, Saginaw pump, single big block setup. Boat is a 24-7.

If so, do I need the longer (big block) 12" one?

Thanks, rob

My Fountain came with powersteering coolers on both engines. The originals are 2" dia x 9 inches long, a dual cool unit with oil cooler for the second tube.

It is my understanding that the powersteering coolers are necessary.

yes, the long higher RPM's will cause the fluid to foam, also some say to use only the GM high performance P/S fluid, I use it in my Hardin setup..

Thanks guys

A good GM style fluid for these older pumps is Redline synthetic PS fluid. Used extensively in road racing apps. Really puts an end to boil over and foaming. Great product.

Ive always used Dexron ATF. Never had any issues with steering for years. Should i have been using power steering fluid?

In the older pumps Dexron is ok to use. Really just a hydraulic fluid with friction modifiers and red Dye added (these don't have any effect in a P/S system). Some of the newer GM pumps, especially hydro boost like Duramax, spec the new GM power steering fluid and do not like ATF. Some of that is related to viscosity, however there is the issue of seal compatibility and that boils down to additives. Many of the Mercruiser pumps spec'd ATF, and in many power steering systems it is the correct fluid. I would stick with ATF. As mentioned it works very well in the older GM saginaw pumps.

Quite a few manufactures (toyota is one) spec ATF for PS systems. However you will notice most come with an amber fluid. It's not PS fluid, just ATF without dye. As you know some systems are very sensitive (Honda/Acura) and if you use anything but a Honda fluid they will have issues. Luckily the saginaw design tolerates either PS fluid or ATF.

Ok, I have the old Saginaw pumps. Gonna keep rocking the ATF. One thing I've liked about ATF in my steering , trim, and tab pumps, if some spills or leaks, it cleans up easy, unlike normal oils and gear lube.

I`m not putting a power steering cooler back on this year, I had this little gay ass one that probably wasn`t doing jack anyway. Mild Blunders was leaking and we by passed that ***** and I don`t remember any negative effects. One less thing to worry about imop


I`m confused, one power steering pump, two coolers , one per motor?

Some boats have a P/S pump on each engine.

You are correct, we did bypass my cooler and I didnt see any negative effects from it. I have another cooler for it, I probably will install it though. The new cooler I have for it is like 2''X12" I believe. Latham recommends a 2x9" bundle, or 3x6'' bundle cooler for their steering systems.