Power Steering fluid HOT

[Peeker]

I’m still at the go-kart stage. My car has the power boost out of a 96 Mustang Cobra. I went to check the fluid after running the car and the reservoir cap was really hot. I needed to grab a rag just to get it off and then I checked the fluid and of course it was hot also. I’ve thought about adding a transmission cooler to it since it also uses transmission fluid. It would probably work better than the single tube cooler that is part of the stock setup. Any thought or experiences from other 4.6 L guys? Thanks

[michael everson]

I have heard of some using an oil cooler in the front opening as a power steering cooler.
Mike

[KDubU]

I added a oil cooler for mine. I believe Paul, aka EdwardB, had it with one of his roadster builds and he included the part number of course! Now to find that info...

Edited to add that it was similar to this and I attached to the front cross bars.

https://www.summitracing.com/parts/prm-1002?seid=srese1&gclid=Cj0KCQjwhIP6BRCMARIsALu9LfntM_OERlJiTN1-1HIUSLrBRRckcV21WdDvpbzuuvtY48AUBBKZo5EaAr2rEALw_w cB

[Jeff Kleiner]

I added a 3 pass cooler to mine after realizing how hot the fluid was getting during autocross runs and track days.

https://thefactoryfiveforum.com/attachment.php?attachmentid=134055&d=1598115978

It's the sustained high RPM that really generates the heat which I wouldn't think you are seeing with simply running the car in go cart stage. You mentioned "transmission fluid"---I can't say for certain whether that is contributing to a high heat situation but I'd probably change to a true PS fluid. I've had good results with both Honda and Royal Purple fluid.

Jeff

134055

[Peeker]

When I was getting all my fluids together the transmission fluid is what I was told to use in the power boost, even though it’s a different transmission fluid from my T45 transmission. I also thought about mounting it just at the bottom of the radiator so that the fan would help cool the fluid. I did watch a video where a guy added one and said to add it to the return line from the rack and it is low pressure so high pressure lines would not be required. Any thought especially since I just bought all new high pressure lines yesterday.

[Joecobr]

I installed a small cooler only because the ‘98 Cobra I took my drive train out of had a long cooling tube in front of the radiator. My cooler is about 2” x 6”. Don’t have the part number off hand.

134068

[Bob Cowan]

When I was getting all my fluids together the transmission fluid is what I was told to use in the power boost, even though it’s a different transmission fluid from my T45 transmission. I also thought about mounting it just at the bottom of the radiator so that the fan would help cool the fluid. I did watch a video where a guy added one and said to add it to the return line from the rack and it is low pressure so high pressure lines would not be required. Any thought especially since I just bought all new high pressure lines yesterday.

DO NOT install the cooler in the high pressure side! Pressure can be 1,500 psi or more. You might have the lines to handle the pressure, but finding a cooler to match would be very difficult and expensive. And, there's no functional advantage.

[Peeker]

I wasn’t going to mount it on the high pressure side. I was asking if on the low pressure side you need a high pressure line from the rack to the cooler then back to the reservoir. Hope that makes sense.

[Bob Cowan]

I wasn’t going to mount it on the high pressure side. I was asking if on the low pressure side you need a high pressure line from the rack to the cooler then back to the reservoir. Hope that makes sense.

Oh, sorry. The answer is no, you do not. Just use standard low pressure PS hose and hose clamps. IIRC, the low pressure side uses a bigger diameter hose.

[walt mckenna]

I’m still at the go-kart stage. My car has the power boost out of a 96 Mustang Cobra. I went to check the fluid after running the car and the reservoir cap was really hot. I needed to grab a rag just to get it off and then I checked the fluid and of course it was hot also. I’ve thought about adding a transmission cooler to it since it also uses transmission fluid. It would probably work better than the single tube cooler that is part of the stock setup. Any thought or experiences from other 4.6 L guys? Thanks

The single tube cooler has worked fine for me. I am not aware of it getting hot at the track because I have never had a reason to check. Fluid color and reservoir level look fine when I perform a routine service check. I will be interested to hear what others have to say.

[edwardb]

For my power steering builds, I've used a Derale Compact Fluid Cooler 13310 2 Rows, Copper/Aluminum, Black, -6 AN Male Threads Inlet/Outlet, on the side of the fan shroud. Installed in the low pressure return line. Granted I don't push my cars real hard, but fluid overheating has never been an issue. Not an expensive part and cheap insurance.

https://hosting.photobucket.com/albums/ab234/edwardb123/Factory%20Five%2020th%20Anniversary%20Mark%204%20R oadster/Power%20Steering/.highres/IMG_0205_zpsyizjbcsf.jpg (https://app.photobucket.com/u/edwardb123/a/2ee2c52c-e6bf-4d57-91d7-d0d38a58ffa8/p/191271e4-3bff-4a15-a87d-c9a851c87498)

[Peeker]

I ended up replacing the power steering pump. I disconnected the high pressure off the pump and wasn’t getting any flow when I spun the pump by hand. I’ve got it all connected back up. I ran the engine and I’m not getting the temperature build up, but I’m not getting any power steering or assisted brakes. I bled it by cycling the steering 5 times and cycled the brakes 3 times. Did that a total of 50 times. I’m wondering if somehow I’m not doing the bleeding properly? I’m not getting any bubbles or foaming so I don’t think I have air in the lines.

[edwardb]

I ended up replacing the power steering pump. I disconnected the high pressure off the pump and wasn’t getting any flow when I spun the pump by hand. I’ve got it all connected back up. I ran the engine and I’m not getting the temperature build up, but I’m not getting any power steering or assisted brakes. I bled it by cycling the steering 5 times and cycled the brakes 3 times. Did that a total of 50 times. I’m wondering if somehow I’m not doing the bleeding properly? I’m not getting any bubbles or foaming so I don’t think I have air in the lines.

Sure you have it plumbed correctly? Did you get boost before? PS typically doesn't require anything special to prime. Some instructions (like KRC) say to prime by spinning the pump with a drill motor. By often that's not necessary. Typically primes and starts providing boost almost immediately or by turning the steering wheel back and forth a couple times once the engine starts. 50 times? Something isn't right.

[Peeker]

134456

This is how I have it Plummed.

[edwardb]

134456

This is how I have it Plummed.

Used that same diagram with my #7750 build that had PS and hydroboost PB. Worked fine so not sure what to say. Other than it should prime almost immediately as I said before. Hope you can figure it out.

[Peeker]

I ended up pulling the pressure line from the pump and hooked a direct pressure gauge up. Spun it thru with a drill and either I have had two bad pumps or the gauge is defective because I’m reading 10-20 psi.

[Peeker]

Well I’ve got my power steering and power brakes. The pressure fitting off the pump was the wrong one. This is the one that was in there.

134475

There is a port that got covered by the extended fitting
This is the one the is proper one and it works fine now

134476