Power Steering cooler insides???

Brentathon

Petty Officer 1st Class
Joined
Dec 29, 2009
Messages
399
In trying to fix my puzzling high-rpm overheat issue on my 1991 Merc 5.7L, I stuck my finger into the powersteering cooler, and it felt like there was an inner pipe section approx 3/4" diameter, and I was expecting the little "tubes within a tube" type of heat exchanger design.
Has anyone looked at the inside of these powersteering coolers? Is there simple a large (3/4") open flow path for the saltwater???
 

HT32BSX115

Supreme Mariner
Joined
Dec 8, 2005
Messages
10,083
Re: Power Steering cooler insides???

That's all the cooling a PS system needs. Same on my 454 and it was the same on my previous OMC 460.

Remember that's "cold" water going thru it. If you ware running "engine temp" water, you'd need a more robust cooler.

If you have a "high power" over heat issue. the same rule apply for just about any overheat.

raw pump, water flow (with NO air bubbles) through the supply hoses, oil and PS coolers, t-stat housing, block, heads, manifolds and risers.


If you do not have enough flow, depending on how much restriction there is, the flow you do have may not be enough to carry the heat away.

It may be enough at lower power settings but not enough for higher power.

There's always excess water flow for any engine (that's why you need a t-stat)
 

Brentathon

Petty Officer 1st Class
Joined
Dec 29, 2009
Messages
399
Re: Power Steering cooler insides???

Thanks for the reply.
Yeah, because I was imagining a heat exchanger that had lots of small tubes within the outer housing, but I guess the typical Mercruiser powersteering cooler simply has a large open inner bore of almost the same I.D. as the hoses that hook up to it?
 

HT32BSX115

Supreme Mariner
Joined
Dec 8, 2005
Messages
10,083
Re: Power Steering cooler insides???

Thanks for the reply.
Yeah, because I was imagining a heat exchanger that had lots of small tubes within the outer housing, but I guess the typical Mercruiser powersteering cooler simply has a large open inner bore of almost the same I.D. as the hoses that hook up to it?
\

Pretty much.

Mine didn't stop any of the raw pump impeller pieces.....they went right on thru to the oil cooler which DOES have holes small enough to stop most everything that gets past the pump....
 
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