Resolved How to properly bleed power steering?

[BLACK'98DSM]

I left the cap off the reservoir and turned the wheels back and forth like I read you should do. I could see some air bubbles coming up through the reservoir, so I know it was working. But I continued this process for 20 minutes an there is still what feels like some air in the system.

Should I do it for longer? Or am I missing something?

 

[silvreclips]

What is the car doing that makes you think there is air in the system?

Last time I unhooked my pump and let the lines drain, I filled the system back and when I started the car the pump started whining like hell and immediately foamed the fluid.

If the fluid it not foamed when your driving it, any air should work it's way out

 

[BLACK'98DSM]

Last time I unhooked my pump and let the lines drain, I filled the system back and when I started the car the pump started whining like hell and immediately foamed the fluid.

That's exactly what is happening.

How do I stop it?

 

[rabenne]

To bleed the system you hold the steering wheel at the lock positions for a few seconds to allow the pump to overcome the pressure relief valve.

So turn the wheel all the way left with the car running. turn until you cant turn any further, and hold for 2-3 seconds. Then do the same all the way to the right. Repeat both sides a couple times.

Then there should be no air in the system, because when the relief valve opens it purges fluid (and any air in the system) into the reservoir.

 

[BLACK'98DSM]

To bleed the system you hold the steering wheel at the lock positions for a few seconds to allow the pump to overcome the pressure relief valve.

So turn the wheel all the way left with the car running. turn until you cant turn any further, and hold for 2-3 seconds. Then do the same all the way to the right. Repeat both sides a couple times.

Then there should be no air in the system, because when the relief valve opens it purges fluid (and any air in the system) into the reservoir.

With the cap off?

 

[rabenne]

Shouldnt matter... I am relatively sure I have never taken the cap off to do so... As the air is displaced in the system the fluid from the reservoir will take its place. Air will be purged into the reservoir. After doing this, open the cap and top it off... if it is totally empty you may need to add some fluid and bleed it again. Keep doing so until you see no fluid level drop (air volume increase) in the reservoir.

Or, it would not hurt to do this with the cap off and top it off as you go... Either should work fine!

 

[BLACK'98DSM]

I will try again in the morning. If I still have air issues then I guess something isn't sealed well.

Thanks guys!

 

[rabenne]

I should also mention that a partially filled system can often cause foaming of the fluid. If you see foamy fluid, let the system sit for a while (30mins-1hour?) to get the fluid and air to separate again. Then continue.

 

[ThunderChild]

Technically, you are supposed to remove the PS belt and spin the pump with a drill at slower speed, with an extended reservoir and have the old fluid go into a catch receptacle till clean fluid comes out while cycling the wheel lock to lock. This prevents aerating (foaming) of the fluid since the pump speed is slower. It takes two people to do unless you're crafty.

I have also done flushes with the engine running, but it generally takes more time to get any air out of the system. Subarus seems especially finicky with this method.

Either way, time could be your biggest factor here, letting the air bleed out. But it will continue to froth the fluid if you drive it regularly as-is.

 

[silvreclips]

@ThunderChild got it right. I unhooked the return line and dumped it into a bucket. The feed line to the pump I connected it to a hose and a transmission funnel hanging from the hood. With the car on jack stands I cycled the wheel back and forth maybe 6 times. Then unplugged the coil and cranked the car over to spin the pump. I did this until the fluid came out clean. Maybe 5 cycles. Hooked it all back up and it was perfect.

 

[609DSM]

https://www.dsmtuners.com/threads/power-steering-noise.525230/#post-153737465 not sure how your situation relates in terms of what issues you're having, mine is working perfectly fine right now.

If your wheel is feeling hard to turn but your fluid is filled, your pump might be going bad. If your pump is cavitating the fluid in your system, you have a broken seal inside the pump allowing it to suck in air into its system and the pumping of said air again and again creates cavitation.

The Turkey baster method works okay, most recommend a vacuum pump to rid the system of all fluid and then refill. Hope some of this information helps.

 

[rabenne]

You should not have to remove hoses unless you are trying to flush the system. If you cant get it to stop foaming... it would be worth a try.

I have bled dozens of hydraulic power steering systems (on at least that many different vehicles) and never once needed to remove any hoses or draw from an aux reservoir. That said, do whatever works!

Best of luck!

 

[BLACK'98DSM]

If your wheel is feeling hard to turn but your fluid is filled, your pump might be going bad.

It is a new pump I installed on Monday.

 

[BLACK'98DSM]

Trying to bleed it right now. I will let you guys know how it goes.

 

[rabenne]

Be patient. Keep it topped off. What fluid are you running in the PS system? Just curious?

 

[BLACK'98DSM]

Be patient. Keep it topped off. What fluid are you running in the PS system? Just curious?

Mercon V

 

[BLACK'98DSM]

They must have given me a defective pump. Good thing it is under warranty

It doesn't work no matter what I do. It whines loud as hell constantly, and if I turn the wheel all the way in one direction at idle it tries to kill the engine. If I drive it above 4k rpm it makes an ear-piercing screeching sound. Even when I have the fluid between the min and max markers it still doesn't work. It acts like there is no fluid at all. In fact, I think it is harder to turn the car with this pump then it is with no power steering at all.

I will be trading this pump in for another new one whenever I find the time.

 

[609DSM]

Definitely sounds like a faulty pump, sorry to hear they sent you a bad one. When you get a good one it should be a breeze to fill the fluid and get it running through the system.

 

[BLACK'98DSM]

When you get a good one it should be a breeze to fill the fluid and get it running through the system.

I sure hope so, this is annoying!

 

[609DSM]

I know man, I had to drive around for almost two weeks with a completely shot rack and pinion. Came home from the movies with the wifey and my system was making some awful bad noises. Thought to myself "oh god here it goes" then it stopped making noise, the rack leaked all over my driveway. Then when I reinstalled a new one I rushed the filling process and it was cavitating a bit but I finally leveled it out and did what another user said to do on an old post and it works like a charm now.

 

[BLACK'98DSM]

I put the new properly built pump in last night. Took only 5 minutes to bleed it, and it works like a charm. Smooth and quiet, I couldn't ask for more.

So for future reference: they might have sent you a bad part!