71firebird400

Hi,

My steering rack started leaking out the top so I had my local mechanic install a new AC Delco unit. I picked the car up yesterday from his shop and on the way home I noticed there is an obnoxious hissing sound that is resonating through the steering column. You can hear it under the car, but it is barely audible under the hood. It is most easily heard in the cabin where the noise is obnoxious (easily heard over regular road noise). I haven't had a chance to talk to the mechanic (he won't be back until Tuesday) but I need to get the car back on the road ASAP so I can get to work. I jacked it up today and ran the steering from lock to lock about 30 times, there were a few small bubbles surfacing in the reservoir but the fluid level did not drop appreciably. Test drove the car and it is still making the noise.

Questions-

1. Any idea what is making the hissing noise!? It goes away if I put slight tension on the wheel, but shows up when you're going straight down the road (no steering input).

2. How hot should a power steering pump get? Maybe I'm paranoid, but my pump seems to be getting warmer than I'd expect after a short 5-10 min test drive.

3. The car turns much sharper to the right than it does to the left. This was not the case with the old steering rack.


I need to get this back together as soon as possible because I rely on the car to get me to and from work. I've googled the sh*t out of this and have found people on other forums with similar symptoms, but I have not stumbled across a solution.

Thank You!
Mark

sjsingle1

iTrader: (1)

is the air all bled out?

71firebird400

As far as I know, the air is bled out. I simply ran the car from lock to lock (in the air, with it turned off) about 30 times. Anything else I can do to help bleed it?

Thanks,
Mark

71firebird400

Another thing to add- the power steering pump seems louder than it was before (it is now whining with RPM). This, along with the excessive heat, makes me think that the new rack is overworking the pump....like there's possibly a restriction in it?

This could all be paranoia, but I am just trying to figure out what could possibly be causing the issue.

SS SLP2

iTrader: (8)

try steering lock to lock about 10 times with engine running and full weight on the ground, drive 10 min then repete 10 times should see a improvment.
rack should turn equel both ways if tie rod ends are adjusted correct, you should get a complete alignment with checking the rear thrust line after install the rack
Johnny

wssix99

iTrader: (5)

Maybe - or the rack might be bad. Did you get a new rack or a re-manufactured one?

There is a pressure relief valve in the pump to prevent this from happening.

Odd that you are still getting air bubbles in the system. They usually bleed out pretty easily and quickly. I wonder if your pump may also be going bad... (If the rack is good, that might be the thing.)

71firebird400

This is the AC Delco rack, I believe it was reman (cost about $350 through the dealer). I have swung the wheels back and forth in the air and on the ground and I am not getting anymore bubbles. However, the noise is still there. Pump still seems to be getting hot, and I don't think it was going bad because until the rack was replaced it was silent. Just seems very suspicious to me that as soon as the rack was replaced the pump would start showing signs of going out?

I am planning on getting an alignment, but want to figure out the noise first. I am not driving the car (except for around the block), as I don't want to wear out my relatively new tires.

Thanks for all the help, hopefully I can get a hold of the mechanic today and see what he wants to do.

71firebird400

Talked to the mechanic and he thinks the noise I'm hearing may be from residual air in the lines; he recommended driving it a couple days and see if it gets quieter. He also thinks that the fact I have 1.5 turns to the right, and only 1 turn to the left could be fixed by an alignment but that sounds like a stretch to me. I could understand if it was only off a little bit.

Power steering pump is still noticeable louder than before, and feels HOT to me but I am not sure what is normal temp for them.

wssix99

iTrader: (5)

Sounds to me like your mechanic needs some extra time so he can run and get out of the country before you come for him to replace the faulty reman rack.

Your PS cooler runs around your cooling system, which will bring the two in to equilibrium. If your thermostat is 210*, then you can expect that your PS temperature could get up to that level.

This article describes a stock temperature of 175* as "cool," which would be in line with my statement above: http://www.gmhightechperformance.com...all/index.html

Again, a bad rack could only cause the system to overheat if you have a faulty pump with a bad pressure relief valve.

71firebird400

wssix99- Thanks for the advice. Just out of curiosity, there isn't a special type of PS fluid required is there? I've always assumed PS fluid is interchangeable, but I suppose there could be different types. Just throwing things out there in case I am naive to something.

wssix99

iTrader: (5)

Na - our cars take run-of-the-mill DOT PS fluid.

Just a thought. I assume our units are a rack and pinion type. If so, you theoretically shouldn't have any difference in the rack function if you turn it left vs. right.

I'm wondering if your alignment/toe may be so far off that you are getting the different behavior when you turn left vs. right and that having the toe so far off may be putting the system under additional pressure/stress, causing the noise.

- When the car is idling, standing still - does it make noise?
- When the car is idling with the front wheels in the air - does it make noise?

71firebird400

In the air it was not making the noise, on the ground (at a standstill) the noise is still there but not as bad as when I'm driving. Car tracks straight, but obviously toe-in was "eyeballed". I am having an alignment done ASAP (might not be until the end of this week) to check that measurement, but am also hesitant to waste money if the rack is off a tooth. Kind of puts me in a tough situation.

wssix99

iTrader: (5)

Yes... If you are comfortable adjusting the tie rods, I'd suggest doing a "ghetto alignment" first and see if it improves things.

Just take two boards and clamp them so they sit flat on the outside of the wheel. Then mark the boards at a distance away from the center of the hub, one forward and one rearward. The measurements forward and rearward should be equal and the further they are out from the hub, the more accurate you will be.

Then measure the distance between the passenger and driver side boards. Adjust until the measurements are equal and you should have 0 toe.

71firebird400

Does anyone know how far the rack should move in either direction? I'm thinking of jacking the car up and measuring the distance the rack moves left and right from it being "centered". I assume the measurements should be identical? I think this would nail down if the huge left turn radius is rack induced or something else, would it not?

Just thinking of things I can check before asking the mechanic to put another new rack on it. Talked to an alignment shop this morning and I may have them align the car, still undecided on if I want to blow $70 or not (assuming I'll have to replace the rack in the next couple of days, and have them realign it).

wssix99

iTrader: (5)

Just measure from a common point in the middle of the car to each ball joint. If the sum of the measurements is the same when the wheels are right/left - all is well with the rack travel.

71firebird400

Got it up on stands and measured it from each ball joint to the center of the crossmember. The rack is going 2" to the left, and 2.5" to the right. Measured it several different ways and all the numbers agreed, it is definitely going the extra .5" to the right.

What do you think about that? Bad rack, or 'close enough'?

sjsingle1

iTrader: (1)

hopefully your meckneck.....centered.....the rack before he installed it

71firebird400

Well considering the steering column can only interface with the rack in one position the next "closest" position would be 180 degrees one way or the other....or am I wrong in that assumption?

Thanks!

sjsingle1

iTrader: (1)

when i installed my rack.......i turned the shaft by hand full left and right and found the center............then matched the steering wheel to match the rack center

wssix99

iTrader: (5)

Sounds like a good place to measure from.

Are you measuring to the ball joint on the end of the tie rod end? I'd expect it to move more than 2", but I could be off.

You can't measure left/right like this because if the "center" place is a little bit off to one side, it will double the error you see at the sides.

With the wheels left, you need to measure to the right and left tie rod end. Then add the measurements. Next, turn the wheels right, repeat the left and right measurements and add them together. If the added measurements equal each other, then your geometry is even side-to-side and you should be able to fix any issues with an alignment.


Are you also taking in to account the position of the steering wheel in all this? Its irrelevant and as sjsingle1 points out, it can be fixed by a good alignment. (Beware - I've had some alignments where they didn't center the steering wheel. Real annoying. I always remind the tech to center the wheel and check it first thing when I get the car back.)