Power steering cooler

[Lanzg]

We did a ton of testing, built cool machines, made entire clear steering systems, killed a bunch of pumps, made a huge mess over and over and over. It was an amazing time to be alive.



We tested pressure and temps on both sides of coolers, and all throughout the systems.



Unfortunately, most cooler brands don't advertise pressure drop, sillier than that, most are rated by the amount you tow, your steering likely doesn't care nor is it affected. I'm convinced Universal means transmission or engine oil. The low-pressure side (Cooling circuits) see maybe 50 psi on a transmission and maybe 15 psi on a motor, seen spikes over 400 in steering systems. The flow rates are similar in the transmission, engine and power steering systems 2-8 gallons a minute. One would also have to keep in mind that the term steering system is a little too broad to have one sword with which to slay every dragon. Today we will talk about systems with steering gears for the valve, engine driven pumps for the pumps, and some sort of cooler. If anyone has questions about full hydro set ups or race car goodies reach out any time.



There are exceptions to everything. Guys have been running transmission coolers forever and had success. Plenty of them have exploded, plenty of them have caused terminal pump failures "but I have a cooler on it". This info doesn't help as there isn't any way to quantify which cooler works and which doesn't when there's no agreed upon specs to measure them by when using them in a steering system.



There are some good rules of thumb and some things to think about that can help you make a steering system work well and live a long life, and each part and it's installation have as much to do with it as the cooler, less though, if it's a good flowing quality cooler.



Log style, extrusion style, heat sink, whatever they call them where you live, are super popular for steering systems with good reason.



1. They are stout, the material is typically thick and due to the nature of their construction they handle higher pressure well.

2. The smallest hole in the cooler is the one the fluid is coming in through and exiting through, the rest of the column is larger, this causes the least amount of drop and restriction.

3. Volume, a rarely thought of but valuable tool in cooling anything, the 14 in extrusions we used to us add about a qt to the system, that's huge when you are starting off with 2-2.5 qts.



Those aren't the only style, stacked plates, tube and fin, and tube and Plate can all be made to work, but they aren't all made the same.



1. If the tube that runs through the fins is smaller than the inlet/outlet, it is restrictive. (Tube and Fin)

2. If the Plates are crimped tightly (whether it's the end or cap or the entire capillary) then the entire path of the fluid is smaller than the inlet and out let, this is restrictive, some are constructed where this is real bad, others have larger volumes, it's difficult to know without cutting them apart.

3. Many of these coolers are made from very thin material, and as we have spoken, the crimped method they are constructed with is not better with thinner material.

4. The racing aftermarket has come in and made some radiator-style coolers with billet tanks, thick wall tubing for the inner tubes, well-spaced fins with huge areas to weld them together so they stay together. These things make me happy, I love using them, they are difficult to package, have their own fans and you could even mount one of these heat slayers improperly to the point that it puts heat into the system.



Installation matters, all coolers are heat exchangers, the temperature outside fighting the temperature inside. This also applies to the reservoirs, which is in its own right an exchanger. If the temperature of the air outside your cooler, even if it's being forced through it or around it (This is usually worse) is higher than the temperature inside of the cooler, you are adding heat to the system. I must also say don't make your cooler an air trap, it will fill up with air and not fluid and cool nothing, in the bottom out the top, all out the top or all on the side if its horizontal.

Sorry to drone on about this, I have been on trial about power steering pumps most of my adult life and if this helps one person, it was all worth it.

LG

 

[duffer]

We did a ton of testing, built cool machines, made entire clear steering systems, killed a bunch of pumps, made a huge mess over and over and over. It was an amazing time to be alive.



We tested pressure and temps on both sides of coolers, and all throughout the systems.



Unfortunately, most cooler brands don't advertise pressure drop, sillier than that, most are rated by the amount you tow, your steering likely doesn't care nor is it affected. I'm convinced Universal means transmission or engine oil. The low-pressure side (Cooling circuits) see maybe 50 psi on a transmission and maybe 15 psi on a motor, seen spikes over 400 in steering systems. The flow rates are similar in the transmission, engine and power steering systems 2-8 gallons a minute. One would also have to keep in mind that the term steering system is a little too broad to have one sword with which to slay every dragon. Today we will talk about systems with steering gears for the valve, engine driven pumps for the pumps, and some sort of cooler. If anyone has questions about full hydro set ups or race car goodies reach out any time.



There are exceptions to everything. Guys have been running transmission coolers forever and had success. Plenty of them have exploded, plenty of them have caused terminal pump failures "but I have a cooler on it". This info doesn't help as there isn't any way to quantify which cooler works and which doesn't when there's no agreed upon specs to measure them by when using them in a steering system.



There are some good rules of thumb and some things to think about that can help you make a steering system work well and live a long life, and each part and it's installation have as much to do with it as the cooler, less though, if it's a good flowing quality cooler.



Log style, extrusion style, heat sink, whatever they call them where you live, are super popular for steering systems with good reason.



1. They are stout, the material is typically thick and due to the nature of their construction they handle higher pressure well.

2. The smallest hole in the cooler is the one the fluid is coming in through and exiting through, the rest of the column is larger, this causes the least amount of drop and restriction.

3. Volume, a rarely thought of but valuable tool in cooling anything, the 14 in extrusions we used to us add about a qt to the system, that's huge when you are starting off with 2-2.5 qts.



Those aren't the only style, stacked plates, tube and fin, and tube and Plate can all be made to work, but they aren't all made the same.



1. If the tube that runs through the fins is smaller than the inlet/outlet, it is restrictive. (Tube and Fin)

2. If the Plates are crimped tightly (whether it's the end or cap or the entire capillary) then the entire path of the fluid is smaller than the inlet and out let, this is restrictive, some are constructed where this is real bad, others have larger volumes, it's difficult to know without cutting them apart.

3. Many of these coolers are made from very thin material, and as we have spoken, the crimped method they are constructed with is not better with thinner material.

4. The racing aftermarket has come in and made some radiator-style coolers with billet tanks, thick wall tubing for the inner tubes, well-spaced fins with huge areas to weld them together so they stay together. These things make me happy, I love using them, they are difficult to package, have their own fans and you could even mount one of these heat slayers improperly to the point that it puts heat into the system.



Installation matters, all coolers are heat exchangers, the temperature outside fighting the temperature inside. This also applies to the reservoirs, which is in its own right an exchanger. If the temperature of the air outside your cooler, even if it's being forced through it or around it (This is usually worse) is higher than the temperature inside of the cooler, you are adding heat to the system. I must also say don't make your cooler an air trap, it will fill up with air and not fluid and cool nothing, in the bottom out the top, all out the top or all on the side if its horizontal.

Sorry to drone on about this, I have been on trial about power steering pumps most of my adult life and if this helps one person, it was all worth it.

LG

If one is seeing 400 psi spikes in the return line, you have a good deal more problems than just the cooler assuming this is still a conventional PS setup as opposed to full hydraulic steering . And personally, I don't care much for the finned can type coolers if you are mounting them in front of the radiator. No different to your engine cooling than having a block of wood obstructing the air flow. That and I don't think they are any stronger than the typical tube and fin style, probably less strong with the interior can surface area as opposed to a tube cross section area. I run one of those cans on my 3B to cool down the output of the York OBA but that is set at 150 psi, not 400 and it's not obstructing any air flow to the radiator.


My background in this sort of cooling comes from 3000+ psi hydraulic systems in Cats and other heavy equipment which make PS systems look pretty trivial.

 

[KennethS]

Yeah but you guys don't have 100% humidity in August. That's what makes it hot out here

I spent 40 years on the Gulf Coast so I’ve experienced high humidity. Humidity and temperature are inversely proportional, so the hottest part of the day has the lowest relative humidity.

And humidity affects evaporative cooling systems (like people sweating) which vehicles do not have.

I go back to the Gulf Coast regularly and have worked outside in June, July, and August and it has ALWAYS been 20+ degrees cooler there than in Phoenix. Sure I sweated until I was drenched after 8 hours but at no point did I feel as if I would die from heat exhaustion as would happen in 115+ actual temperatures.

 

[Strizzo]

You are my new best friend since no one ever has said that about anything I have ever done.

Question on the two options (-6 and -8 cooler kits). Is the cooler the same between the two, and just the lines and fittings different for the one intended for PSC systems, or is the cooler different as well? Curious if someone were to install the stock PS cooler and later upgrade to PSC if they could reuse the cooler and purchase the larger lines and fittings later on.

 

[Lanzg]

Question on the two options (-6 and -8 cooler kits). Is the cooler the same between the two, and just the lines and fittings different for the one intended for PSC systems, or is the cooler different as well? Curious if someone were to install the stock PS cooler and later upgrade to PSC if they could reuse the cooler and purchase the larger lines and fittings later on.

If its single pass the cooler is the same, the double pass will be different.
LG

 

[mrblaine]

Question on the two options (-6 and -8 cooler kits). Is the cooler the same between the two, and just the lines and fittings different for the one intended for PSC systems, or is the cooler different as well? Curious if someone were to install the stock PS cooler and later upgrade to PSC if they could reuse the cooler and purchase the larger lines and fittings later on.

On the single pass, everything is the same except for the line OUT of the cooler back to the stock plastic reservoir if you order it that way. The intent was to help folks who need a cooler now but are going to upgrade later so all they have to do is change the return back to the reservoir and convert it to -8 to match the inlet.

We do have the option for -6 in and out for those that will likely never upgrade but want cooling for the stock pump.

 

[mrblaine]

If its single pass the cooler is the same, the double pass will be different.
LG

The double pass stuff is painful to get the routing figured out. Did ya'll ever mess with multiples of the 1.75" stuff to create a double or triple pass?

 

[mrblaine]

No different to your engine cooling than having a block of wood obstructing the air flow.

That really isn't how air flow works. What you are saying is the equivalent of saying an airplane wing does something wonky and finds a way to somehow dispose of part of the air flowing over the top of the wing. There is exactly the same amount of air as before when the air flow meets up behind the trailing edge. You will have exactly the same amount of air flow behind the extruded cooler that is in front of it because that is how air works. It may be more turbulent, it may be warmer, but there will be the same amount.

My background in this sort of cooling comes from 3000+ psi hydraulic systems in Cats and other heavy equipment which make PS systems look pretty trivial.

We're running at a little over 60% of that number so not really trivial.

 

[MikeE024]

And personally, I don't care much for the finned can type coolers if you are mounting them in front of the radiator. No different to your engine cooling than having a block of wood obstructing the air flow.

I’d know if the finned cooler sitting above my Setrab cooler in the grill was a problem for my Mopar radiator. I daily my boosted rig on 35s in southern Arizona with no issues.

 

[MikeE024]

That really isn't how air flow works. What you are saying is the equivalent of saying an airplane wing does something wonky and finds a way to somehow dispose of part of the air flowing over the top of the wing. There is exactly the same amount of air as before when the air flow meets up behind the trailing edge. You will have exactly the same amount of air flow behind the extruded cooler that is in front of it because that is how air works. It may be more turbulent, it may be warmer, but there will be the same amount.

We're running at a little over 60% of that number so not really trivial.

This reminds me of folks incorrectly blaming high ECTs on a bumper mounted winch.

 

[Lanzg]

The double pass stuff is painful to get the routing figured out. Did ya'll ever mess with multiples of the 1.75" stuff to create a double or triple pass?
View attachment 683558

I haven't messed with it like that, I like how modular that one is but it seems they would get tall quick by the time you make the corner. I have double stacked the normal sized coolers and hooked them together with a custom made sweeping elbow, it worked well. Moroso or some one makes a set up like that and the coolers are mounted to each other at the end.

I have a dual pass unit that I made -8 by machining the inlet/outlet offset outward and welding -8 Males on it, Not sure the juice was worth the squeeze but it was an all or nothing deal.

LG

 

[duffer]

That really isn't how air flow works. What you are saying is the equivalent of saying an airplane wing does something wonky and finds a way to somehow dispose of part of the air flowing over the top of the wing. There is exactly the same amount of air as before when the air flow meets up behind the trailing edge. You will have exactly the same amount of air flow behind the extruded cooler that is in front of it because that is how air works. It may be more turbulent, it may be warmer, but there will be the same amount.

We're running at a little over 60% of that number so not really trivial.

More blizzard of BS and I was under the illusion it was spring. This comes down to basically two factors: the thermal conductivity of the material involved and the temperature gradient across the interface. Period.

Sooo, you can obviously choose the material, and the common selection there is copper, aluminum, and brass. The relative thermal conductivity of those materials is copper has twice the capacity of aluminum and aluminum twice that of brass. Why aluminum radiators work so much better than the brass versions.

The remaining variable is that gradient, the steeper it is, the more heat transferred. And this is obviously where the air flow becomes the driving factor. With the finned aluminum tube style cooler mounted perpendicular to the air flow, only ONE fin on that cooler (the one parallel to the air flow) is achieving a sort of maximum heat transfer. All the rest of them are compromised to some degree and most especially at the rear of the cooler next to the radiator where you probably have negative air pressure.

The tube and fin coolers will suffer a little of this too as the temperature of the air flow though the fins increases front to back decreasing the gradient but the big difference here is all those fins are parallel to the air flow rather than across it.

And the final ingredient: that air flow obstruction to the engine cooling radiator: maybe not a block of wood, but that solid fined tube will indeed greatly diminish the air flow though the radiator fins directly behind it. The tube and fin coolers also hinder that air flow but since they don't really disrupt the laminar flow, the effect is much, much less.

 

[g.hayduke]

How many tubes do the heat sink style log coolers have?

I should have been more explicit that those guidelines are only applicable to the Setrab-style coolers.

One fat tube is probably about the least possible restriction.

 

[ColoJeep]

More blizzard of BS and I was under the illusion it was spring. This comes down to basically two factors: the thermal conductivity of the material involved and the temperature gradient across the interface. Period.

Sooo, you can obviously choose the material, and the common selection there is copper, aluminum, and brass. The relative thermal conductivity of those materials is copper has twice the capacity of aluminum and aluminum twice that of brass. Why aluminum radiators work so much better than the brass versions.

The remaining variable is that gradient, the steeper it is, the more heat transferred. And this is obviously where the air flow becomes the driving factor. With the finned aluminum tube style cooler mounted perpendicular to the air flow, only ONE fin on that cooler (the one parallel to the air flow) is achieving a sort of maximum heat transfer. All the rest of them are compromised to some degree and most especially at the rear of the cooler next to the radiator where you probably have negative air pressure.

The tube and fin coolers will suffer a little of this too as the temperature of the air flow though the fins increases front to back decreasing the gradient but the big difference here is all those fins are parallel to the air flow rather than across it.

And the final ingredient: that air flow obstruction to the engine cooling radiator: maybe not a block of wood, but that solid fined tube will indeed greatly diminish the air flow though the radiator fins directly behind it. The tube and fin coolers also hinder that air flow but since they don't really disrupt the laminar flow, the effect is much, much less.

Curious what your thoughts are on the other side of the cooler , on the fluid side the " log " style cooler would seem to be greatly affected by the boundary layer next to the cooler tube wall . This would leave a lot of the fluid passing through the center of the larger diameter of the cooler without much drop in delta T . Thank You .

 

[GATORB8]

Curious what your thoughts are on the other side of the cooler , on the fluid side the " log " style cooler would seem to be greatly affected by the boundary layer next to the cooler tube wall . This would leave a lot of the fluid passing through the center of the larger diameter of the cooler without much drop in delta T . Thank You .

It's my understanding that the use of the heat sink style "log" cooler is because the cooling is substantially unnecessary at speed, the use case for the cooler is during low speed maneuvering and the internal/external heat sink style has increased mass for urgent heat storage rather than tube/fin which is for rapid transfer of heat to the air.

 

[ColoJeep]

heat sink style has increased mass for urgent heat storage rather than tube/fin which is for rapid transfer of heat to the air.

Why in the world would you want "increased mass for URGENT heat storage " ??? This sounds kinda dumb . we are talking about a P/S cooling system . Either you need one or you don't , you likely don't need one that can store " URGENT HEAT STORAGE " I'm not trying to be a dick , but I have to throw the B.S. flag on this . Thanks .

 

[GATORB8]

Why in the world would you want "increased mass for URGENT heat storage " ??? This sounds kinda dumb . we are talking about a P/S cooling system . Either you need one or you don't , you likely don't need one that can store " URGENT HEAT STORAGE " I'm not trying to be a dick , but I have to throw the B.S. flag on this . Thanks .

The goal of a light weight tube and fin radiator is to quickly transfer the heat to the air that is rapidly passing by it. This is literally called a "Heat Sink" style cooler and doesn't even specifically require significant air flow.

 

[ColoJeep]

The goal of a light weight tube and fin radiator is to quickly transfer the heat to the air that is rapidly passing by it. This is literally called a "Heat Sink" style cooler and doesn't even specifically require significant air flow.

Isn't the heat sink Log style cooler what we were talking about , with it's amazing ability for URGENT heat storage . Brother , I'm throwing a second B.S. flag on this play .

 

[duffer]

Curious what your thoughts are on the other side of the cooler , on the fluid side the " log " style cooler would seem to be greatly affected by the boundary layer next to the cooler tube wall . This would leave a lot of the fluid passing through the center of the larger diameter of the cooler without much drop in delta T . Thank You .

Yep. All about exposed surface area too. Pretty clear in my mind which style of cooler is more efficient but your thoughts may vary-—-

 

[mrblaine]

More blizzard of BS and I was under the illusion it was spring. This comes down to basically two factors: the thermal conductivity of the material involved and the temperature gradient across the interface. Period.

Sooo, you can obviously choose the material, and the common selection there is copper, aluminum, and brass. The relative thermal conductivity of those materials is copper has twice the capacity of aluminum and aluminum twice that of brass. Why aluminum radiators work so much better than the brass versions.

The remaining variable is that gradient, the steeper it is, the more heat transferred. And this is obviously where the air flow becomes the driving factor. With the finned aluminum tube style cooler mounted perpendicular to the air flow, only ONE fin on that cooler (the one parallel to the air flow) is achieving a sort of maximum heat transfer. All the rest of them are compromised to some degree and most especially at the rear of the cooler next to the radiator where you probably have negative air pressure.

The tube and fin coolers will suffer a little of this too as the temperature of the air flow though the fins increases front to back decreasing the gradient but the big difference here is all those fins are parallel to the air flow rather than across it.

And the final ingredient: that air flow obstruction to the engine cooling radiator: maybe not a block of wood, but that solid fined tube will indeed greatly diminish the air flow though the radiator fins directly behind it. The tube and fin coolers also hinder that air flow but since they don't really disrupt the laminar flow, the effect is much, much less.

One of my greater joys in life is watching folks spout theory and then practicable application proves that either incorrect, or inconsequential. My blizzard of bullshit is based in the experiences of 100's of folks with TJ's who run extruded heat sink steering coolers, a Setrab radiator style trans cooler below that, and then a winch in front of that. If there were any merit whatsoever to your assertions, they would overheat pulling out of the driveway and they don't. You got big fancy words, all I got is little words and actually doing the work and my little words prove your big ones are to be soundly ignored.