Power Steering Cooler

[Dajkzo]

One of the upgrades on my 70 RR is the Borgenson Power Steering Kit. I really like the modern feel. However, both the new pump and the steering box run hot. Damn hot as in 240º F. I made a simple aluminum bracket on the mill and mounted a small Derale cooler on top of the pump where it gets plenty of air flow. Now after 30 minutes of driving on curvy secondary roads the system stays 190-195º.

 

[440+6]

Looks good!
My gtx has one from the factory.

 

[dadsbee]

Nice, but as noted maybe they should have followed the factory OE lead. After spending big money for aftermarket it shouldn't be up to the buyer to reinvent the wheel.

 

[Dajkzo]

Nice, but as noted maybe they should have followed the factory OE lead. After spending big money for aftermarket it shouldn't be up to the buyer to reinvent the wheel.

I agree. The high temp surprised me. The cooler was cheap https://www.summitracing.com/parts/der-13213. I had upgraded to a new ColdCase radiator and with a 4-speed, didn't bother with the integrated cooler but now I think it would have been useful to cool the steering.

 

[dadsbee]

No because your radiator is running around 220 or so... not gonna cool that P/S unit.

 

[493 Mike]

Good info! I bought a cooler for my 65 Belvedere project because it has PS and hydro boost braking. I'm thinking about mounting the cooler down on the lower gravel/splash shield below the grill.
Mike

 

[Dajkzo]

Good info! I bought a cooler for my 65 Belvedere project because it has PS and hydro boost braking. I'm thinking about mounting the cooler down on the lower gravel/splash shield below the grill.
Mike

I looked at pictures of a factory setup and wanted to use the existing return line without having to extend it. I'm running a flex fan and there is plenty of air flow even when sitting still. The mounting tab is just a piece of 6061 and goes on the pivot bolt between the pump brack and the water pump housing. I had turned some spacers to align the power steering pulley so now the mounting tab serves as a spacer. And then a #10-24 cap screw into a tapped hole on the bracket (some blue locktight just in case). The body of the cooler is tight against the pump bracket along with a lip on the mounting tab to lock the cooler in place.


Now that I look at it, I could have printed a better tab on my buddy's 3D printer. Maybe when I install the new 440. 3D printing is cool, check out this drink holder that fits on a winch. With Kevlar or carbon fiber it's incredibly strong and light.

 

[wyrmrider]

good
and that tube and fin is not even the most efficient for its size
nice job
and good reason not to mount it down low where it's cooler
what fluid is recommended with that box?
OEM equivalent fluid for the Chrysler mfd pumps is hard to find
I used to use STA LUBE but it's gone

 

[Dajkzo]

good
and that tube and fin is not even the most efficient for its size
nice job
and good reason not to mount it down low where it's cooler
what fluid is recommended with that box?
OEM equivalent fluid for the Chrysler mfd pumps is hard to find
I used to use STA LUBE but it's gone

I'm using Valvoline synthetic PS fluid. The one with "NO" stop leak. The system has been on for 18 months and the seals are fine. I didn't notice the high temp until I upgraded the radiator and fan. While checking temps I put the infrared gun on the pump and it was 240º. I've been doing some updates with the purpose of getting the car ready for a 440 (hoping for 500HP). The last step is swapping the 8 3/4 for a new S60 from Dr Diff.

 

[origcharger]

No because your radiator is running around 220 or so... not gonna cool that P/S unit.

Just thinking if the bottom tank of your radiator is running 220 you may have more to worry about than PS fluid temperature

 

[68 Sport Satellite]

One of the upgrades on my 70 RR is the Borgenson Power Steering Kit. I really like the modern feel. However, both the new pump and the steering box run hot. Damn hot as in 240º F. I made a simple aluminum bracket on the mill and mounted a small Derale cooler on top of the pump where it gets plenty of air flow. Now after 30 minutes of driving on curvy secondary roads the system stays 190-195º.
View attachment 976670 View attachment 976671

I know this is an old post, but did you use a bracket to mount that PS cooler? If so, do you have a P/N or did you fab something up?

 

[khryslerkid]

I made a simple aluminum bracket on the mill and mounted a small Derale cooler on top of the pump

 

[Dajkzo]

I made a mount from aluminum on my milling machine. You should be able to make something on a drill press.

 

[furyus]

I just added a cooler to my Sport Fury. I hid it under the battery, at the frame rail.
I didn't do a temp reading before, and after, but I thought that before the cooler, the ps was very hot.

 

[68 Sport Satellite]

I just added a cooler to my Sport Fury. I hid it under the battery, at the frame rail.
I didn't do a temp reading before, and after, but I thought that before the cooler, the ps was very hot.

I also hid my PS cooler under the battery below the frame rail. It worked fine driving around town several times less than 20 miles, BUT then I did a 4hr RT drive and the PS Pump failed at the end of the drive on an off ramp. Luckily I wasn't pushing the car hard and fast and was able to steer the car. I've since replaced the pump with a new one and am moving the cooler location for better air flow in front of the radiator at the lower bumper opening. The under battery location doesn't get any direct air flow in my 68 Plymouth Satellite as it's blocked by a metal panel at that spot. If you have non-freeway rear gear ratio the pump works even harder as the pulley spins faster. I have 3.55's in my car.

 

[Kern Dog]

The overwhelming majority of cars from the muscle car era had NO power steering cooler and they seemed fine.
Of course they had skinny tires....
The cooler will operate better with more airflow through it but one main advantage of it is that it allows the fluid to shed heat simply by being outside of the pump reservoir. With the fluid being routed outside of the reservoir and through an exposed tube like so:

....you have fluid that is now flowing through a tube that is outside and better able to cool down.
Stock steering boxes don't seem to be as sensitive to overheated fluid as the Borgeson steering boxes do. Maybe the Borgeson needs more pressure to operate and even though I am no engineer, it seems that more pressure would result in more heat.

 

[68 Sport Satellite]

The overwhelming majority of cars from the muscle car era had NO power steering cooler and they seemed fine.
Of course they had skinny tires....
The cooler will operate better with more airflow through it but one main advantage of it is that it allows the fluid to shed heat simply by being outside of the pump reservoir. With the fluid being routed outside of the reservoir and through an exposed tube like so:

View attachment 2045317

....you have fluid that is now flowing through a tube that is outside and better able to cool down.
Stock steering boxes don't seem to be as sensitive to overheated fluid as the Borgeson steering boxes do. Maybe the Borgeson needs more pressure to operate and even though I am no engineer, it seems that more pressure would result in more heat.

Yes, I've also read of some with stock steering boxes just adding a long length of tubing with no cooler running under the rad support, which gives the fluid time to cool before re-entering the pump.
Over the weekend I read another mopar owner thread where someone else also installed a Borgeson unit with the cooler under the battery tray and it overheated. They moved the cooler to a spot with more airflow and have been problem free for several years. I'm hoping for the same.

 

[493 Mike]

I wound up mounting right on the radiator support.
Mike

 

[Kern Dog]

I read another mopar owner thread where someone else also installed a Borgeson unit with the cooler under the battery tray and it overheated. They moved the cooler to a spot with more airflow and have been problem free for several years. I'm hoping for the same.

While I am not adamantly declaring that the “under the battery tray” location was scientifically proven to be adequate, I wonder if other factors influenced your condition. Sure, my cooler is mounted to the pump and in direct flow from the fan but also is getting HOT air coming off of the radiator and radiant heat from the engine block. Mine has not faltered due to heat.

You mentioned that your assist gave out after a long drive which was on a straight freeway, not one where the steering box was being stressed from sawing the wheel back and forth. This tells me that the condition should worsen if you were on a twisty road where you really were working the wheel. I suspect the issue is that either the steering box simply demands external cooling where most stock units don’t.
I had a stock steering box lose assist in the red car as well as two GM cars, all had Saginaw pumps. These three incidents were all with “seasoned” parts. The red car had no cooler at the time. After I added one, I have not had any troubles with assist failing except during my debacle with hydroboost back in 2022. (Unrelated and I don’t want to get into that now)
Without further testing under stress, I’d expect the Plymouth to have been fine with the cooler where it was and the actual problem be elsewhere. Maybe the pump was failing, maybe it has been shimmed for reduced pressure, maybe the fluid was too thin. Relocating the cooler costs little to try and I’ll admit, in front of the radiator is a better location. Late model vehicles with tack and pinion steering often have external coolers. My 2007 Dodge truck has one.