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:
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:
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
, 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:
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:
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:
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:
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.