How do I fill and bleed a completely dry power steering system?

[ShooterMcGavin]

I have a bent power steering hard-line under the truck. I want to replace it with a new one... Taking the bent line off will result in the power steering fluid draining out of the ps system, to some extent at least. I am fine with letting it all drain out, or maybe that's exactly what I shouldn't do? (Try to do it real quick and keep fluid in the lines? ...as one option?)

Assuming that a lot/most of the the fluid drains out when I replace this hard line, what special steps do I need to take in order to fill the power steering fluid, from dry, without causing wear to the ps pump before it has fluid in the lines?

Everyone likes pictures, so...

 

[pluton]

I don't think there's any special procedure. The fluid drains out, you put it back. I've had the P/S pump become starved of ATF during my normal fluid exchange. It makes a bit of noise, you add more ATF, and eventually it doesn't make any noise. My P/S pump was 16 years old when I did this, BTW.

I had a shop install a brand new steering rack, and when I dropped the 4Runner off I supplied them with a quart of Dexron ATF to top off any loss.
When I picked up the car, they said they had used the whole quart, which means it completely drained out, and was then refilled without incident.
Still fine 1.5 years later.

 

[99Runnr]

I believe you just take the weight off the wheels, and turn it lock to lock to burp the system. Top off the reservoir as required. That's how I did mine and it worked like a charm at least.

 

[ShooterMcGavin]

I believe you just take the weight off the wheels, and turn it lock to lock to burp the system. Top off the reservoir as required. That's how I did mine and it worked like a charm at least.

I know that's the process for flushing the system when it's full. Should it also be the same for a newly drained system? Maybe I'm making a bigger deal than I should... Maybe filling the fluid before bleeding it will get most of the air out?

 

[joe.greenhalgh1]

Remove your damaged line and let the fluid drain into a suitable container. Then replace the line with new or hand bent hard line. Fasten the line to specifications (like a brake line, hand tight, not Arnold tight).
Clean up any mess at this point.

Now fill your power steering fluid reservoir to the MAX or HOT area on the dipstick. It will settle some air out as you fill it. Then start the engine and top up as necessary but this time just keep fluid up to at least the cold, don't want to have to suck fluid back out if it's super full. Now turn the steering wheel back and forth from lock to lock, and top up the system as necessary.

The pump will make noise as it runs dry, not really going to do any damage as you're going to be topping it up right away anyways. Hence filling it to max before you start the engine.

Finish adjusting your fluid level once you're confident most of the air has come out, clean up any mess or excess fluid, and then double check for leaks before calling it a day.

 

[ShooterMcGavin]

Remove your damaged line and let the fluid drain into a suitable container. Then replace the line with new or hand bent hard line. Fasten the line to specifications (like a brake line, hand tight, not Arnold tight).
Clean up any mess at this point.

Now fill your power steering fluid reservoir to the MAX or HOT area on the dipstick. It will settle some air out as you fill it. Then start the engine and top up as necessary but this time just keep fluid up to at least the cold, don't want to have to suck fluid back out if it's super full. Now turn the steering wheel back and forth from lock to lock, and top up the system as necessary.

The pump will make noise as it runs dry, not really going to do any damage as you're going to be topping it up right away anyways. Hence filling it to max before you start the engine.

Finish adjusting your fluid level once you're confident most of the air has come out, clean up any mess or excess fluid, and then double check for leaks before calling it a day.

Thanks! That was a perfect description of the process. I really appreciate all the tips.

 

[joe.greenhalgh1]

Thanks! That was a perfect description of the process. I really appreciate all the tips.

Anytime! Glad to help!

 

[TorqueOfTheDevil]

As above old stuff out new stuff in.

it helps if you can leave it to settle before starting, but weight off the front wheels and lock to lock before starting the engine will help.

It usually gets pretty stirred up at first with lots of tiny air bubbles but settles down eventually... (usually on next start up after sitting).

Keep an eye on the level as you'll be surprised how much it drops, and you don't want to run the pump dry.

 

[TheDurk]

I am a big fan of RTFM. Here are the FSM instructions on bleeding. They say nothing about filling a dry system. If I were doing a dry system, I'd fill first to level, doing the lock-to-lock with engine off until it would not take any more, as described in thew first part of the link below. Then I would drop it and continue with engine on also as described in the link below:

http://tacoma.site40.net/4Runner_96-02_Repair&Wiring/techinfo.toyota.com/ileaf/02toyrm/02toypdf/02rmsour/2002/024runne/sr/psf/blee.pdf

 

[Unner]

I wouldn't over think it. Fill it up, have someone start it and be ready to pour more in because it's gonna suck that right up, then to bleed run the wheels back and forth until it sounds/feels smooth again. I think you're supposed to go almost full lock when doing this, but not quite.

 

[T5RUNNER]

If you start the engine it will suck it all up really fast. In the past I've either had a friend crank the engine and turn the steering wheel back and forth, or primed the pump slowly using a drill/driver while adding fluid (belt has to be off). You don't want the pump to run dry, the bearings can be damaged quickly.

 

[nevada]

I am a big fan of RTFM. Here are the FSM instructions on bleeding. They say nothing about filling a dry system. If I were doing a dry system, I'd fill first to level, doing the lock-to-lock with engine off until it would not take any more, as described in thew first part of the link below. Then I would drop it and continue with engine on also as described in the link below:

http://tacoma.site40.net/4Runner_96...toypdf/02rmsour/2002/024runne/sr/psf/blee.pdf

THIS.

do it this way. it is the fastest way to get all the air out.

when its running, the pump will be moving the fluid, and it will be pushing some of the air through the system. microscopic air. it then takes a lot longer to get it all out of the system.

when its off, the rack/gear box is moving the fluid, it wont aerate the fluid like the pump does.

 

[ShooterMcGavin]

THIS.

do it this way. it is the fastest way to get all the air out.

when its running, the pump will be moving the fluid, and it will be pushing some of the air through the system. microscopic air. it then takes a lot longer to get it all out of the system.

when its off, the rack/gear box is moving the fluid, it wont aerate the fluid like the pump does.

Great info. I totally agree with your method, both of you. Thanks!