Derf00

Removing the fuse disables the fuel pump which means the engine won't run after it is starved of fuel. It will just crank over.

After you have the fuse put back in, you will probably have air in your fuel lines or not enough pressure to start the car. By putting the fuse back in and turning the key to 'On' but not starting it, you are priming the fuel system. Just like you stated. When you've starved the engine of fuel, it can take a couple of priming cycles to get the fuel system properly primed.

P.S. There's more than one way to disable an engine and allow it to crank without starting. I generally prefer to remove fuel from the scenario because if you turn the engine over too much and there is fuel, you can flood the motor which can make it harder to start when you are ready to.

kevsgt

Okay, I see. But why don't I want the engine to run? Is it because the power steering pump would be operating after faster RPM, while if the engine is just cranking it would pump at a slower rate?

In other words, couldn't I drain the PS fluid while simultaneously filling it with fresh fluid all while the car is running normally?

kevsgt

Bumping. Still have this question.

kevsgt

Welp, I could not get the metal clamp off the return line. The tabs are on the underside, so I can't squeeze them together. Tried prying, no luck. Tried unscrewing the reservoir so that I could manipulate it to get a better angle. No luck. And in the process I tilted the reservoir sideways such that I probably introduced air into the line.

So I siphoned some fluid out and refilled. I'll do that 3-4 times this week and hope that helps. When I took the siphon tube out, I noticed some crud on the tip.

Derf00

You want the engine off and just crank it because even though the PS return line is low pressure, there's still pressure there and the fluid will flush our really fast. If you leave the engine running and try to flush out your system like that one of two things will happen Either A giant mess from getting PS fluid everywhere or B you run the system dry because you're not refilling fast enough or run out of fluid before you cut the engine. That could lead to PS pump or Rack & Pinion failure.