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Old 10-18-2015, 03:27 PM   #10 (permalink)
oil pan 4
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Quote:
Originally Posted by OilFilter View Post
This is the pump I was thinking about:
edit: Sorry, can't post link, I don't have enough posts yet. It's available at Surplus Center for $200. 1.4 GPM at 2500 PSI, more GPM at less PSI. 1 min on/5 min off duty cycle. 200 amps at 12v. (for 2500 PSI)

If the PS required 1000 PSI or less, it would probably be enough to power it for turns and such. Duty cycle is questionable. Probably puts out more flow than an economy car pump does.

BUT...

If I hooked that pump up to a small hydraulic accumulator, with a pressure switch to turn the pump off when full, will hydraulic fluid continue to flow through the steering box? Would I need some kind of valve to turn the box "off" when I'm not turning?

Just forget about the accumulator. The power steering system works completely opposite of what you would need to make an accumulator work.

The pump curve for these pumps looks something like 2.5gpm at 0psi, 2gpm at 1500psi and 1.5gpm at 2500psi.

Should draw around 100 amps at 2gpm and 1500psi.
I have a fluke325 amp clamp so I will know precisely how much power its using.
Bailey pumps has the perfect pump 2.1gpm with a relief set at 1,400psi.

You do not want to turn the box off. The steering box is just like every other kind of actuator, when its full of fluid and it gets moved by out side force, it starts to pump fluid. You actually want to open the hydraulic connection between the pressure and return lines when your electric pump is "off".
When you turn the wheel the box is still trying to move fluid around. That is why I am getting a "single acting pump". I am going to try to convert the "dump" valve to normally open. "On" will turn the motor on and close the valve so that all the fluid is forced through the box. "Off" will kill power to the pump and open the valve allow all fluid to bypass.

I found this out when I pulled the power steering pump off my Camaro years ago. I removed the P/S pump and drove down to the parts store because I was 17 (which means I was broke) and had just enough $ to get the pump but not cover the core charge.
I noticed after removing the pump the wheel was easier to turn, I figured fluid was going everywhere, then sure enough when I got to the parts store the disconnected lines had spewed fluid all over the drives side under the hood.
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