Power steering cooler...Really???

[Tail_Gunner]

My power steering cooler is leaking and I was about to replace it then I began wondering what on earth for. With today's modern oil and the low temps that exist on a marine engine is this just overkill on a little I/O...

 

[Outsider]

Power steering doesn't know or care what the engine temp is. It does, however, care about the fluid temp, hence the reason for a cooler ... :facepalm:

 

[Tail_Gunner]

Yes I am aware its fluid temp...my bay maybe runs 5 degree's hotter than the ambient air temp...how do I know that...I was going to run some high performance amp's in the bay and took temps at wot and monitored it most of the day...Actually very little fluid would be cooled if I have this right. The only time fluid would be transferred is during a turn.

 

[mr 88]

I just went through the season without my cooler hooked up. I did add about 3 feet of hose to it which I left coiled on the bottom of the hull.That in itself will cool down the fluid,Anyway never had a problem.

 

[alldodge]

My power steering cooler is leaking and I was about to replace it then I began wondering what on earth for. With today's modern oil and the low temps that exist on a marine engine is this just overkill on a little I/O...

IMO most time not having one would be fine. So long as you don't run for long periods. The heat is what will kill the pump, so if after running for your normal period, check the fluid level between when you started and level now. If it is much higher then normal, then maybe you might need it.

 

[achris]

....Actually very little fluid would be cooled if I have this right. The only time fluid would be transferred is during a turn.

Wrong... Steering pumps are constant displacement, fluid is flowing the whole time the engine is turning... That means it's getting hot all the time... Running without the cooler is not a wise choice...



Chris......

 

[Tail_Gunner]

Wrong... Steering pumps are constant displacement, fluid is flowing the whole time the engine is turning... That means it's getting hot all the time... Running without the cooler is not a wise choice...



Chris......

http://www.pirate4x4.com/tech/billav...ng/index2.html [FONT=Arial, Helvetica, sans-serif]Saginaw "P" style pump[/FONT]
[FONT=Arial, Helvetica, sans-serif]The "P" style saginaw pump is like that which is found in a HUGE number of oem cars and trucks. Very often it has an attached, integral fluid reservoir, and is called the "can-o-ham" pump because the teardrop shaped reservoir is reminiscent of the shape of an old-fashioned canned ham. There are also variants that have a more circular or round shaped integral reservoir, along with a secondary remote reservoir - most notably pumps for vehicles such as 1 ton 4x4's and diesel trucks that use hydro-boost brakes. Depending on the exact model of the pump, "P" style saginaw pumps are rated for anything from 2.4 to 3.5 gallons per minute (gpm) flow and 1100-1450 psi pressure. The importance of flow and pressure ratings will become evident later on in the "system design" section.

I assume you are referring to this type of pump.[/FONT]


http://www.carcraft.com/techarticles/ccrp_1112_power_steering_coolers/


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.

Read more: http://www.carcraft.com/techarticles/ccrp_1112_power_steering_coolers/#ixzz3FxvVmJoi

 

[achris]

Read the articles, and that is NOT how power steering on a Mercruiser works...

 

[Lou C]

Just guessing here but I think the cooler was felt to be needed because at planing speeds, the force against the drive is much greater when you are turning than at low speeds.So the force against the steering system is much greater and that puts a strain on the pump. Kind of like when you put much bigger tires on a 4x4. In fact some towing packages for trucks added a p/s cooler. In vehicles its probably the opposite, steering forces on the PS system are greatest at low speeds. Anyone who has driven cars with manual steering knows this. Last one of those I had was an '80 Honda Civic....had 2 VWs before that with manual steering and brakes as well.

 

[skydiveD30571]

Mercruiser and Volvo may use different systems, but the PS section of my VP manual explains fluid flow at all times, with varying amounts into different valves to provide hydraulic force to the steering joint during turns.

 

[thumpar]

My last boat didn't have power steering so it needed the fin type anode. It took a bit of tuning but was still a compromise since at different speed it had different pull. The power steering has to work all the time even to just keep the wheel straight.

 

[Tail_Gunner]

I am going to take out the boat on some prolonged high speed runs and see what the temps rise to without and cooler......

 

[achris]

Add a few tight and shallow turns, and a few 'docking manoeuvres' in with that... As I said, even when the steering is not being turned the full volume of fluid is still being pumped and therefore, heated. Add some manoeuvring and the heat loading rises exponentially.

As heat exchangers and the associated plumbing are not cheap, the engine suppliers are not going to be adding it on just for convenience. History of tests and checks will be telling them they NEED to add the cooler....

 

[Tail_Gunner]

I tend to agree with you achris, I am just very inquisitive.

 

[dan t.]

I would tend to think that the P/S cooler is not nessesary on the average boat. Think about it , the same Saginaw pump is used on Chevy 4x4s with no cooler. I can slog through the bush all day in my old 76 with 35 in tires, the steering is being constantly sawed back and forth. On top of that the pump is right beside the exhaust manifold and a 190+ degree blast of air off the rad is blowing over it. Does it boil the oil? Not chance. The environment in a boat is pretty friendly compared to an off road 4x4. If it were mine I would eliminate it without a second thought.

 

[bruceb58]

Many vehicles also have power steering coolers plus a lot of air flow.

No way I would remove it.

 

[Scott Danforth]

your PS cooler can be repaired for under $30 and replaced for about $100

trust me, both Mercruiser and Volvo would have eliminated it if they could have. just like they would have eliminated the oil cooler or fuel cooler if they could have.

 

[Fun Times]

Since there is a fear of P/S fluid boiling over at higher temp, the last thing a manufacture would want to put in a bilge of a boat to possibly drain in the body of water the boat is in is any type of oil.... Plus Mercruiser is trying to keep the engine room temperature under 176 degrees to help keep fuel vapor down to a minimum so a power steering cooler would help there as well since there is a constant steering load on the drive while under way.

 

[Walt T]

Fluid sitting still tends to settle at ambient temperature. Add movement and the fluid will heat up. Add pressure and that will add more heat on top of that. The more movement and pressure the more the molecules move and that movement generates heat. As to whether or not a cooler is needed all I know is some boats have them and some don't. My boat has the can o ham pump on a Volvo system and no cooler. A great deal of boats were made with no cooler, and a great deal were made without them. I have not come across a power steering failure attributed to oil overheating. With all the systems on boats, power steering is one of the very reliable systems. Do you need a cooler? If it had one I would keep it. You wont harm it that way. If you leave it off will it harm it? I pretty much doubt it. I've come across a few boats that the owners removed those coolers, and they said they had forgotten about taking them off, it was so long ago. A point was made earlier that if Merc and Volvo didn't think they needed those they wouldn't put them on. I agree. They cost money and that makes the price of the boat higher. And THAT is what it's all about.