Power Steering Cut-out

[tommyt31]

Since I'm on a posting role...Any ideas on how to manually bypass the power steering pump so there is less load on the engine when you don't want to use power steering? I was hoping for a method that would be as easy as a flip of a switch so I could turn it back on in a hurry if I really needed to. I was thinking of a servo actuated hydraulic valve connected to the outgoing oil line. When activated it would re-route the oil back to the oil reservoir. I'm not sure if this would work, though. I am assuming if the oil is not doing any work, then the load is going be very small on the engine. Any thoughts?

[Kemper]

That's a tough one. There would certainly be less resistance, but the engine would still be turning the pulley, pump, etc. I don't know if the gains would be measurable, but every little bit helps. I remember seeing kits for muscle cars to convert water pumps from ICE power to electric. Wonder if there is something like that for power steering? That would be the ideal way to shut it off or turn it on quickly, without replumbing hydraulics.

[abcdpeterson]

I think the AC system may have what you’re looking for. I believe the AC in most cars use’s a clutch of some kind in the pulley. The belt is always turning the pulley, but the pulley only turns the compressor when switched on.

Keep in mind I think this will be a safety issue, and I would not recommend it.

[trackermpg]

Originally Posted by abcdpeterson

The belt is always turning the pulley, but the pulley only turns the compressor when switched on.

Keep in mind I think this will be a safety issue, and I would not recommend it.

I'm with abcd. You could possibly(?) fit an electric AC compressor clutch to the power steering pump and turn it on/off at will.

However, 25 years of teaching and evaluating pilots in simulators during emergencies and several years of conducting experimental flight test, and you gain a certain realistic perspective of people actually perform during the stress of an emergency compared to how we think we can or will before the fact. Aircraft designers have continued to make emergency systems that are needed in a time critical manner for control more automated, requiring less actions to be performed immediately during an abnormal situation. Aviation has continued to grow safer for it. In cases when automation is involved in an accident, more often than not is is due to misuse or mismanagement of that system in a manner other then what the designer or manufacturer intended. In the rare cases of a pure system failure, the failed automation is usually considerably more complex than the systems we are talking about with cars. Disabling safety systems that improve the stability, control, stopping capability, or crashworthiness of a vehicle for any amount of time while driving is unnecessarily giving away available safety margins. Believing you will always know when they will be "needed" or not, or that you will simply turn them on during an emergency itself is less than realistic thinking.

Even if you did have the presence of mind and available time to turn the system back on during an evasive maneuver, you would then cause a large and immediate change in the force gradient required for a given steering request (you were applying a certain force to your wheel to steer and suddenly the same force results in a larger reaction), and that in itself could easily lead to a negative outcome.

[kwj]

Good points Tracker. Ones worth ruminating on.

[tommyt31]

Your probably right, tracker and abcd. My first car was an 84 pontiac sunbird with manual steering. It took a little getting used to, but I never considered it unsafe. At faster speeds it was easy to turn the wheel. It was just when you were going less than 5 miles an hour that the wheel was difficult to turn. However, power steering may be harder to steer with no power than a manual steering car (different steering rack).

[WriConsult]

Tracker, I agree with your point that the DIFFERENCE between manual and power-assisted steering could cause a danger, because it would be easy to forget that it's on and in an emergency it would be easy to apply the wrong amount of force.

But I disagree that the lack of power assist on your steering is in itself a safety issue. Maybe you're young. Maybe you haven't been driving long enough to have experience behind the wheel of a car without power steering. But the idea of power steering being standard on all cars is only about a decade old: even on the very nicely engineered Honda Civic, PS was not standard across the line until the 2001 model year.

In fact, I have owned 4 cars ('85, '87 and '90 Civic Wagons, plus a '93 Civic VX) that lacked power steering. I have performed high speed evasive maneuvers in them numerous times, and the lack of assist was never a handicap. In fact, the only real disadvantage was the difficulty of parallel parking. Come to think of it, I would consider the excessive power assist of many US-spec cars to be more dangerous.

If you want to disable your power steering, I think the safe way to do it is to do it permanently.

[Shrek]

I believe this is the major motivation that modern power-assist are electrical. They do not run all the time, only when you apply force to the wheel.

Your car might already have this in place?

[tommyt31]

Not my car...it's a 96 Saturn. I rebuilt the power steering pump, once, so I know it's hydraulic. I have shut my engine off when pulling into a parking spot and have noticed it is difficult to steer (especially with my wider summer tires). At speeds of 10 mph or more I think the steering effort is easily manageable. Although, it would be better to have a manual steering rack for several reasons, I'm not up to that amount of fabrication.