Power Steering cooler plan...

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Joined
Feb 26, 2004
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Oregon
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www.brian894x4.com
I've gathering parts to add a power steering cooler...probably this weekend. Wanted to run the plan by folks who have already done this to make sure I'm not missing anything and see what anyone thinks.

My stock power steering cooler is not rusted at all (which makes it sad that I would have to cut it up) so I'm thinking of utilizing it in my set up.

I'm going to order a heat sink 12" long cooler, with 3/8 fittings on each end. I picked 12" to give me room to work under there with the hoses and connections and also add a temp sending unit. Then cut the stock cooler out, utilizing some of those stock cooler lines to connect to the new cooler. I'm wonder how "flarable" the stock lines will be using a standard 3/8" flare kit. Anyone have any ideas?

As a back up plan, I have a pipe cutter and flare kit on order and could just add all new hard lines like others have done.

I also have plans to add a temperature sender in the line. I don't think I've seen anyone do this and it might be interesting to see what temps the fluid gets too. I already have a trans temp gauge (VDO 150-400 degrees F) and I'm thinking to keep things simply plumb in a sending unit and wire it to my trans gauge with a swtich so I can flip back and forth between trans and power steering temperatures on the same gauge.

By the way, does anyone have any idea what the temperature range is for the power steering fluid?

Finally, will flush with new fluid per the many instructions on here. Thinking of Mobil 1 tranny fluid. Would this work? Anyone have issues? Did some searching and found that some folks seem to be OK while others developed problems, but hard to say if it's the fluid or other issues.

Thanks much for any advise!
 
Pretty much exactly what I have planned including the gauge :flipoff2: . I actually have 5 gallons of the hydraulic fluid that LANDTANK recommended along with expensive hydraulic hose all from McMaster.
 
My 15" cooler came with 3/8" fittings. It came from ebay, very similar to the Derale heat sink coolers. Note that there are two models of each length of cooler; a single pass and a double pass. Single pass has one fitting on each end and dual pass has both fittings on the same end. I doubt the cooling benefit is any different, but it makes it a lot easier to plumb with both fittings on one end.

I flushed/refilled with Mobil 1 ATF and haven't had any complaints yet. Other have used a Mobil 1 hydraulic fluid (DTE24 IIRC). I would think that the ideal temperature range would be the same as the transmission since Toyota specs the same fluid in each, so 140-180ish? Having a temp sender in there would be pretty cool (you would need a ground-able sender since it will be insulated by the rubber hoses)

My only question is why are you doing this if your stocker is still serviceable? That's not meant as bashing, but why fix it if it ain't broke?

:cheers:
 
Just a quick question, NLXTACY, did your cooler kit come with the 3/8" barbed fittings? I see that some do, but they don't show them with the 12" version.

My Delare DID come with the fittings. I actually have the one with the fittings on opposite ends so I am going to try that out although thinking about getting the one with both fittings on either end as well.
 
My only question is why are you doing this if your stocker is still serviceable? That's not meant as bashing, but why fix it if it ain't broke?

:cheers:

Its a known fail point for those dealing with rust. It adds much more cooling although without a gauge on there now I can't quantify it. But the finned design is a proven heat shedder.
 
My only question is why are you doing this if your stocker is still serviceable? That's not meant as bashing, but why fix it if it ain't broke?

:cheers:

I get the pump whine occasionally and it really howls when I'm off roading at low speed, so I know it's overstressed and that's even with new good, new fluid. 33" tires may not seem like much, but I carry a ton of weight in the rig...close to 7000lbs when fully loaded with gear and people.

I'm assuming the heatsink cooler will be better than the stock cooler. We'll see. The thing about the stock cooler is that I think it largely relies on airflow. With my Slee bumper, the cooler is tucked up and out of the airflow, plus at low speeds there's no airflow anyway. The heatsink design doesn't rely entirely on airflow to cool, so it looks like a good option.

So my two reasons are that I really, really, really don't want to have to replace my power steering pump and I certainly don't want it to fail out in the middle of nowhere.

Besides, this wouldn't be the first time I've overkilled anything. :D You should see what I did to my cooling system.
 
Besides, this wouldn't be the first time I've overkilled anything. :D You should see what I did to my cooling system.

haha I just read that section -- you still had some hoses left to replace, and didn't even do them all in silicone!
 
haha I just read that section -- you still had some hoses left to replace, and didn't even do them all in silicone!

Yes sir, that's true. Rear seat heater hoses were not touched. Funny thing, I noticed the paint has flaked off the rear heater tubes, but so far no rust. Lucky to live where we do, but I totally get why these things rust out so many other places!

If I had easy access to silicone hose sections, I probably would have....:D
 
Hrm, seems an aux fan on the PS cooler would make more sense. If you're not getting airflow at low speeds, a bigger cooler will help shed a bit more heat, but nothing helps like passing air over it.............
 
Hrm, seems an aux fan on the PS cooler would make more sense. If you're not getting airflow at low speeds, a bigger cooler will help shed a bit more heat, but nothing helps like passing air over it.............

I'm thinking I might end up doing both. I have a high flow 6" fan (1800 cfm) that I was considering mounting on the tranny cooler to complement my other aux fan. But I don't have tranny overheating issues, and I don't tow trailers, so that really would be overkill. So it might get mounted down by the power steering cooler instead.

The only time I've ever seen more than about 160 degrees on the tranny is when I had to tow a friend of mine up a few pretty steep off road trails. Even in low range, very, very easy on the throttle, it got over 200 degrees, but that's the only time.
 
I get the pump whine occasionally and it really howls when I'm off roading at low speed, so I know it's overstressed and that's even with new good, new fluid. 33" tires may not seem like much, but I carry a ton of weight in the rig...close to 7000lbs when fully loaded with gear and people.

I'm assuming the heatsink cooler will be better than the stock cooler. We'll see. The thing about the stock cooler is that I think it largely relies on airflow. With my Slee bumper, the cooler is tucked up and out of the airflow, plus at low speeds there's no airflow anyway. The heatsink design doesn't rely entirely on airflow to cool, so it looks like a good option.

So my two reasons are that I really, really, really don't want to have to replace my power steering pump and I certainly don't want it to fail out in the middle of nowhere.

Besides, this wouldn't be the first time I've overkilled anything. :D You should see what I did to my cooling system.

Ah, makes sense! The heatsink cooler may also add some more fluid volume to the system compared to the paper clip which would help too. Are you going to rebuild the pump while you have the system torn down? If it's groaning and whining you may have already overheated the system a few times, so all the seals and Orings may be more prone to leaking. The pump rebuild is pretty easy to do.
 
Ah, makes sense! The heatsink cooler may also add some more fluid volume to the system compared to the paper clip which would help too.

Yeah the one I have is an extra two quarts. Add that with an extra quart plus filter with my new reservoir. So with the extra three quarts I don't think I will need a fan at at. But the gauge will tell :D
 
Having more fluid might be as important as any other mod to the power steering system. I understand the 70 series power steering system has a bigger resevior. And a quick search of the 70 series board, reveals they don't seem to have the problems we do with the PS systems.

96r50: I don't have plans to tear the pump apart just yet. The noise is not constant and I'll try other options first. I'm hoping the pump and seals are still in good shape and I don't have any leaks that I know of. It seems to operate and sound normally, except when stressed out on the trail on a warm day.
 
Hey Brian, I just did the pump a few months ago and if the battery tray is out of the way its actually a fairly simple, albeit messy, process to replace it.
 
I pullout all my factory PS cooler lines on my 80 and since I'm running my manual trans now .. use my old tranny cooler for PS ..

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Check with my infrared thermometer and after a day around the town .. the temps on the PS reservoir are around 120°F
 
... Other have used a Mobil 1 hydraulic fluid (DTE24 IIRC).

Mobil DTE light works very well in Toyota systems.

I would think that the ideal temperature range would be the same as the transmission since Toyota specs the same fluid in each, so 140-180ish? ...

That's a good range, most pumped, oil lubed units run best in that temperature range. Wear numbers can be higher at cold temps than slightly overheated. Cold oil holds moisture, that turns to acid, etc, causing cavitation, varnish buildup, etc.

If the rig is operated in cold weather, the size, placement of the cooler is important, it's easy to over cool the fluid. Some vehicles came with the power steering cooler under the hood, in the radiator fan airflow. This works as a simple thermostat, in cold weather the fan output warms, in hot weather cools the fluid.

The biggest issue I have seen is off road, at angles, the reservoir is too shallow and sucks air. My first mod would be a larger/deeper reservoir.
 
I've shown it on other threads already but here is my new reservoir that yes...has NOT been installed.
fittings2.webp
 
Hmmmm, some interesting comments on here.

I'm starting to have 2nd thoughts.....not necessarily because of anything posted here, but the idea of cutting into a perfectly intact and running system is starting to disturb me. If I could remove the stock paperclip without cutting it off (it looks like it has to be cut to be removed, but maybe I'm missing something) this option would sound more appealing.

But I'm starting to lean towards the simple approach of trying a new type of fluid, and a good flush, with either Mobil 1 ATF...or maybe the DTE 24 if I can find it. The DTE 24 still makes me a bit nervous, though. And then add my compact fan to increase airflow over the stock cooler as needed.

Keeping the new cooler around as a possible future project, if needed. This could still be a future project, but I've got a billion little things to do before a major two week trip early next month, so I'm paring down the list for now.
 
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Er not sure why you would need to cut. Its just rubber hose with clamps. You are just extending the rubber lines.
 

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