Fixing an overheating power steering system

Joined
Dec 19, 2006
Messages
2,289
Location
Michigan
Most people never really tax their power steering system. It's just... there. Until it leaks, nobody really ever gives it a second thought. Maybe a fluid change once in a while.

What if you chronically overheat your power steering? Add a cooler, right? What if it's cause by a system design issue and adding a power steering cooler simply won't fix it? Follow me...

I purchased a 2000 Chevrolet Camaro Z28 specifically as an auto-x and track toy. Yeah, I drive it on the street, but I bought it expressly because it's relatively cheap, has huge aftermarket support, is fitted with a good size tire (with the option to go MUCH bigger), and is fast enough.

This is what happened the first time I auto-x'd it:
SmW6cKKh.jpg


That was only after two runs, less than 2 minutes of angry driving. It didn't get better. I didn't have a temp probe with me, but I'd guess temps were well past 350 degrees F. Here's the thing: This is a normal outcome for GM power steering systems! Most just live with it or try to fix it with a cooler, but a cooler is just treating the symptom, not the cause.

Besides puking fluid all over, overheating the power steering fluid has the secondary effect of quickly deteriorating all the seals in the system, particularly in the steering gear or rack. No surprise, my rack was also leaking.

I did mention a cooler. My car, like many 4th gen. F-bodies, has a cooler from the factory. It's fitted to the upper radiator hose and uses engine coolant to cool (or in most cases, warm) the power steering fluid:
xknU0tyh.jpg


GM installed the cooler on the early SS and WS6 models, which were equipped with 275/40-17 tires up front. In 2000, they added the cooler to all V8 cars.

So yeah, it has a cooler, but the fluid will always only be as cool as the coolant temperature. This trips people up and leads them toward thinking a big air cooler will fix it. After all, the fluid is already sitting at 210 degrees because of the factory cooler. Again, a bigger cooler is just treating the symptom, not the cause.

Enter: Turn One Steering

Now, I'm only a customer of Turn One and am in no way affiliated with them. It's just cool to find a shop that is so specialized in one area that they are the de-facto experts. A real part of their business is with NASCAR. Their customer list is a who's who of Cup and Xfinity teams. It's even cooler that they're local to me (relatively local, at least). They're based in Saginaw, MI, former home of GM's Saginaw Steering division. That's not a coincidence.

Anyway, they have some great tech explanations of why GM power steering systems are so prone to overheating. You can read about them here and here, but the short answer is GM pumps flow A LOT (GM used the same pump on dump trucks that they used on Chevettes!) and most of that flow is simply diverted right back into the reservoir by the flow control valve. This constant cycle of pressurization and recirculation allows heat to build and build until it expands and pukes out the pump.

Turn One rebuilds pumps with a close eye on managing flow, reducing recirculation, and ultimately controlling temperature. The downside is less assist, especially at low speed. The upside is you get to keep all your power steering fluid. Fair trade.

As a bonus, Turn One also rebuilds steering racks. So the pump and rack came off and I drove them up to Saginaw for a refresh. Looking at the top picture, you'll see the composite plastic pulley on the pump. Beside being totally cheesy, it completely blocks access to the blots securing the pump. The pulley has to be removed and reinstalled every time the pump goes off and on. Lame. Turn One also makes a sweet billet pulley that has opening that allow easy pump removal and installation. Worth it.

Now comes the bad news: My pump was junk. When I removed it, I noticed there was a remanufacturing sticker on the back. It was also painted black instead of the natural aluminum finish it left the factory with. I noted this when I dropped off the pump and sure enough, I got a call that the pump failed its dyno test (yeah, a power steering pump dyno... sweet!). Something about excessive flow past the pressure relief valve and no way to correct it. They also noted the oil feed port for the shaft bushing was in the wrong location, meaning the pump likely wasn't even an F-body pump in the first place! Of course, all of this may have just made a system already prone to overheating even worse.

So I had to buy a new pump from Turn One. All it takes is money.

New pump in-car:
hGWbrLDh.jpg


You'll also notice an AN fitting on the return port in the reservoir. I re-plumbed the return side of the system with push-lock AN-fittings. The return port fitting is super slick piece offered by Turn One. They also supplied the AN adapter for the return out of the steering rack. It's totally possible to plumb the pressure side with AN, but it requires specialized higher pressure line and fittings ($$$) and there was nothing wrong with my current high pressure hose: It wasn't leaking.

I also ended up replacing the cooler:
jLqVUqph.jpg


Turn One says most applications of their pumps don't require a cooler. I wanted to get the factory cooler removed on the off chance it were to rupture and either allowed coolant into the power steering fluid or power steering fluid into the coolant. If I was going through the effort to re-plumb the return line, I figured I may as well add the cooler now. It's an 18" Derale unit mounted just behind the factory air dam. Yeah, it's not in a direct airflow path, but space in front of the radiator is awkward and remember the part about Turn One saying a cooler likely would not be required. I'm not worried.

Since this is BITOG, I filled it with Red Line power steering fluid. Sorry, you get a stock photo for that:
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Why Red Line? Pretty much because of this: https://bobistheoilguy.com/forums/ubbthreads.php/topics/4472551/1

As a cherry on top, I got rid of the wire thin factory steering wheel with integrated pillow:
u5fgTJAh.jpg


So that's it, stem to stern, a completely rebuilt steering system. I haven't had an opportunity to really give it a work out, which is kind of a let down for the purposes of this post. I can report that the "less assist" trade-off is barely noticeable, but I think that is mostly because it is a manual transmission. With an auto, I think it's much easier to simply idle at parking lot speeds while turning the wheel. With a stick, you're constantly modulating the throttle and clutch, which provides enough revs to keep the pump spinning just that much faster.
 
That looks sharp. I have the stock GM setup on my WS6, but have never really had a problem. I have replaced the pump because of a failed hose once, but got it at the dealer.

Anyway nice job! I do like the steering wheel... A LOT!
 
Looks like a great aftermarket part. Are you monitoring the temps with a gauge at all?

Your powersteering cooler looks very similar to what the 4.6L ford's have out of the factory, only yours is about twice as large. That should keep it plenty cool.

I believe my tbird had it in the exact same location on the car from the factory.
 
Very cool! I don't own a GM product but that was an enjoyable read.

How about some pics of the exterior?
 
Originally Posted By: JustinH
Are you monitoring the temps with a gauge at all?


No gauge. I dipped a temp probe into the reservoir after a normal drive and was reading in the mid-140 degree area.

Originally Posted By: mclasser
How about some pics of the exterior?


damOIjOh.jpg
 
I've gotten the power steering temps under control on my GMs by installing a transmission cooler behind the primary electric fan to cool the power steering.

After a really nasty romp, I can stick my bare finger comfortably into the fluid reservoir.
 
Great write up - and nice car.
I was surprised to first see a similar PS (air) cooler under my small truck - but two years later the PSF was black - and since then been swapping partial fluid once a year via a 200cc syringe ...
 
It's great you have your car set up for the track pounding you want to give it, no I'm not being sarcastic.
But for everyday highway use I think it's overkill. Sure, GM (or whoever) could build a bombproof system for all their cars, how much would that raise the sticker price?.
Mostly people don't drive their cars to its limits and the compromise set-up they leave the factory with works just fine.

But if you want to rip round a race track, pound down a drag strip, or see how far you get off road, anyone who has done it will know a heap of money will be needed to keep it together.
Here's wishing you luck at the track, seems to me you know what takes to do well and will stump up the $$$ to get there.
smile.gif


Claud.
 
Nice Upgrades!! Really like the pulley, Can I ask how much they charged you to rebuild the Rack? I need mine rebuilt.

Are those Hooker Blackheart Headers?
 
Originally Posted By: clinebarger
Nice Upgrades!! Really like the pulley, Can I ask how much they charged you to rebuild the Rack? I need mine rebuilt.

Are those Hooker Blackheart Headers?


$250 for the rack rebuild.

Yes, those are Blackheart headers. They're the mid-length version. I also did the matching true-dual exhaust. I really wanted to do the long-tube, but they weren't available when I ordered and the cost was about 50% more for the headers and exhaust. I'll probably kick myself later for not waiting for the long-tubes.
 
That's nice. I have to say all of my Alfa's had factory fitted PS coolers (long plastic or metal pipe in S that is located in front of a radiator) that worked wonderfully. BMW and FIAT had something similar before everybody went electric.
 
Originally Posted By: MrHorspwer

Yes, those are Blackheart headers. They're the mid-length version. I also did the matching true-dual exhaust. I really wanted to do the long-tube, but they weren't available when I ordered and the cost was about 50% more for the headers and exhaust. I'll probably kick myself later for not waiting for the long-tubes.


I thought so, I have the same system on my car & absolutely love it. I installed a set of 1 7/8" Super Comp's & 3" sections of straight pipe on both collectors for a "Dyno Day" & gained 7 RWHP at 6,000 RPM over the Blackheart 1 7/8" Mid-Length & full exhaust.
My restriction is in the Air Intake, Removing the Air Filter, SLP Lid, & Mass Airflow Sensor netted a 18 RWHP gain at 6,200 RPM running in Speed Density, Injector Duty Cycle hovering around 90%.
Best pull with long tubes, No air intake......431hp/458tq
Best pull with mid lengths, air intake intact....406hp/444tq

I under-cammed my car! But with the Air Intake & Injector upgrades along with a converter re-stall that would have to be done to take advantage.......I'm going to leave it alone, I'm tired of working on the [censored] thing!!

Not trying to de-rail your thread.....I just believe Hooker did an excellent job designing the mid-length's, They would probably out flow many sets of long tubes like Pacesetter & BBK.
 
Originally Posted By: clinebarger

Not trying to de-rail your thread.....I just believe Hooker did an excellent job designing the mid-length's, They would probably out flow many sets of long tubes like Pacesetter & BBK.


No worries on that. Like you said in your audio thread, ls1tech is full of a bunch of cliques. I'd much rather talk about headers and cams with someone here.

It's nice to hear your opinions on the headers. They fit well and seemed well constructed. For the price with the exhaust, I am happy. I like the sound too. Much more Corvette-like with the true dual and x-pipe than the typical Y-pipe 4th gen. It's just so easy to second guess and psych yourself into regretting not buying a different part because some guy on the internet got better numbers or whatever. I'm over it.

The only plans I have left this year is to install a 3.90 gear. Hopefully I can get that done before the next auto-x. There's a slight pinion bearing howl and the pinion seal is leaking all over. Figure now is as good a time as any to swap the gear.

Next year I'll do the cam. I'll probably land somewhere in the 220 degree area on a 114 LSA. I don't want anything radial. I don't plan on touching the heads and unless the very unfortunate happens, it'll stay at stock displacement. I want crisp throttle and a knot of torque at 2,000 RPM.

How much cam did you end up going with? I know it's not apples to apples, since you have more displacement and a much better flowing head. Just curious.

I just started doing some tuning with HP Tuners, getting my MAF curve dialed in before I start on the VE table. It runs pretty well now, certainly on the safe side though. It's intimidating at first, but working on it methodically seems to be netting results. I don't really feel anything, but the numbers are tightening up and coming to where they should.
 
Cam Motion stage 2 LS3
Duration - 220/230
Lift - .578"/.561"
LSA - 114
ICL 110
The torque production is phenomenal....To the point I was blowing through my loose 278mm converter, I now have a tight 245mm Billet Converter & wish I had a little more on the top end.....But as we both know, Once you get used to whatever power your making, You want more & more. And there is always someone faster with deeper pockets!


Specs on the Cam Motion Titan 3 LS1 camshaft are similar to what your after, I instaledl one of these in a LS1/T56 out of a '04 GTO installed in a '69 Camaro.....Longtubes & 4.11's. Runs very strong with a dirty street tune using a wideband. Without dyno numbers to confirm, It "feels" like....It get's up on top of the cam around 2600 & peaks torque around 3400-3600.

Duration - 224/228
Lift - .603"/.595"
LSA - 113
ICL - 109

Not sure it actually meets your torque output at 2,000 RPM criteria, You may have to widen the LSA a bit, Retard the ICL/Installed & lower the duration especially on the Intake.....I wouldn't go under 224 degress for the exhaust on any untouched-production LSx cylinder head.

Cam Motion LS1 Torque Titan V2.....
Duration - 218/226
Lift - .595"/.587"
LSA - 116
ICL - 113

I'm by no means a camshaft expert & urge you to call Kip @ Cam Motion, I've been around LSx engines since they came out & like the SBC's before them.....Folks tend to Over-Cam them for the intended use.

I really like your ride, But I hate you because my steering wheel looks ugly now!!
 
Originally Posted By: clinebarger

Cam Motion LS1 Torque Titan V2.....
Duration - 218/226
Lift - .595"/.587"
LSA - 116
ICL - 113


This is a very intriguing grind. I started down the rabbit hole looking up details on some of the Cam Motion grinds and found myself overwhelmed with intake and exhaust flow theory that I can't say I quite understood, not that I'm an expert or anything. It seems to be a specific grind for a specific purpose.

I will certainly give them a solid look and discuss my needs when the time comes. They seem very well regarded.
 
Always interested to hear what others are doing with their 4th gen LS1's. I removed the factory PS cooler 2 years ago. With it on I saw temps in the summer of 185-190 deg at the reservoir. With the cooler removed, now I see 185-195 deg F on a hot summer day. But, that's just normal driving around. In the winter, it doesn't get above 145-165 deg F now. I didn't want to experience a cooler leak so even at 16K miles on the car it was coming out.

Most of the PS cooler mods I see mount the heat exchanger closer to the air stream. Some have even cut a small hole in their air dam to get some direct flow on the HX....though at a slight degradation to air flow up to the radiator. I keep my PS level at the "fill" line because it will tend to spit out when it gets to 190 deg. Someday I may get around to adding a cooler. For now I change the PS fluid every year just to keep it fresh/durable.
 
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