Problem bleeding power steering system

[NocalFJ60]

hey kevin,What's happenin bro?i was going to pm you for some help on hooking up a kill switch,that's another time.i wish that i have seen this post much earlier coz i would have loaned you my fluid extractor,it would have save you you time and some grief.i saw something similar on Griot's Garage.com,they call it a brake fluid extractor for under 70 bucks.this is similar to what i used when i rebuilt my pump and bleed the system it only took me less than 15 min and 2 quartz of atf.i'll pm you later. john

Sounds good. I have heard of those power bleeders for like helping bleed your brakes it sounds like this is for doing your power steering system. That would be very nice. Hopefully I will not have to bleed the system for a long time.

 

[bigbertha]

Thanks

Thanks for the responses.

Nocal... yeah, I figured it out this afternoon. The truck had been sitting for a day or two so most of the foam had settled. It takes a CRAZY long time to get all the air out. I was rockin and lockin for like 2 hours with the engine off and watching bubbles gurgle up into the res. My arm was all sore and cramped. The pump os groaning a bit even when warm so I think it is getting to be time for a new pump.

Once the ps pump is replaced this engine will be 100% new oem as of last year.

Later.

 

[fj40pinobilt]

I have an older version of the Chasis & Body that came with the land cruiser. It's on SR-34: Replacement of Power Steering Fluid. I did this step. Then I went to the Bleeding step on SR-35. Never could get it to not foam. Had to go back to SR-34 and make sure the reservoir never went empty. Then when I went to the Bleeding step it worked.

Hey ducks,

thanks for posting the pics, I just got a new steering box and when I went to fill it up got a lotta air in the system. I'm planning to take another crack at it this weekend with all the info I have got from this thread.

Thanks Again!

Btw can you post the pics of page SR 35 the bleeding?

Regards,

fj40pinobilt

 

[ntsqd]

Something that I keep seeing mentioned is to "turn the wheel lock to lock." If you go all of the way to lock that would be bad. The reason is that going to lock will cavitate the pump. Cavitation is air bubbles. May as well shoot yourself in the foot. So stop *just* short of full lock, you don't want to ever feel the steering hit the limits in either direction.

Another thing that may help is to 'bump' the steering wheel. I used successive short, rapid, partial turns of the wheel rather than smooth, continuous turning of the wheel last weekend. Seemed to help with that system.

 

[NocalFJ60]

Something that I keep seeing mentioned is to "turn the wheel lock to lock." If you go all of the way to lock that would be bad. The reason is that going to lock will cavitate the pump. Cavitation is air bubbles. May as well shoot yourself in the foot.

Can you explain this more? Where does the air come from?

 

[ntsqd]

My understanding is that the vacuum of the pump causes what could be described as a localized boiling of the working fluid. When you hit the limit stops in the steering the pump tries to push past that and goes to it's maximum demand, then it pulls the most vacuum on the supply side. It's the reverse of using a pressure cap on a radiator to increase the boiling point, the pump's vacuum decreases the boiling point.

The collapse of the bubbles when they move into a higher pressure part of the pump is damaging to the parts around them. I have seen "cavitation erosion" and it looks like little rust pits that have been bead blasted smooth.

 

[NocalFJ60]

I could see how a lot of air in the system with the engine running (high pressure) could cause the bubbles to break down which could cause damage over time. I have done it and you get a lot of air in the fluid and it makes a foamy mess. At the locks is where I would get bubble coming up from the gearbox in the reservoir when getting the air out of the new box.

I just don't believe the pressure would be high enough by just turning the gearbox and using the power piston to boil the fluid without the engine running.

Next time I do this I am going to just put the right top bolt in and then connect both lines and the steering shaft. Then tilt the box so the lines are at the highest point. Then slowly turn the wheel lock to lock and keep the fluid level in range and let all the air out. Then put in the 4 bolts to the frame and tighten them. Then bolt the relay rod to the pitman arm and take it for a test drive and check the fluid.

 

[ntsqd]

Something that I just realized might be misunderstood, my initial comment only applies when the engine is running. With the engine not running hitting the limit stops would make no difference.

 

[Ducks]

Hey ducks,

thanks for posting the pics, I just got a new steering box and when I went to fill it up got a lotta air in the system. I'm planning to take another crack at it this weekend with all the info I have got from this thread.

Thanks Again!

Btw can you post the pics of page SR 35 the bleeding?

Regards,

fj40pinobilt

I loaned out my FSM. I'll try and post it up on Friday.

 

[Eporter]

Ducks, thanks for the pic. I installed a reman PS pump yesterday, followed their "Toyota PS directions", and it was still noisy.

The reman company didn't really cover the need to thouroughly flush the old fluid out. Thus, I was getting lots of air and foam.

I used the Toyota technique and then turned the wheels lock to lock SLOWLY. I think all this really helped.

Fired it up and it was totally silent!

 

[60wag]

To solve the frothy fluid problem, here's my fix - it's easy and has worked on both my FJ60s and FZJ80:

Unplug the coil wire going to the distributor. Crank the engine.

The cranking speed of the motor will pump fluid through the steering pump but not so fast that it foams up. You should be able to get the air out in less than three minutes.

 

[ntsqd]

IME frothy PS fluid is due to going all the way to the steering limits. If you hear the pump make a noise you've cavitated the fluid and it is frothy. Going not quite to the steering limits means no cavitation.

 

[GLTHFJ60]

When I replaced my box and pump, I was able to bleed the system entirely with the tires on the ground turning almost all the way from lock to lock a number of times. Makes no noise and is leak free.