71firebird400

Had the steering rack replaced in my car over a year ago and it was flawless for the first 10 or so months. Now I've noticed a distinct "whirring" noise when I turn the wheel at slow speeds; kind of like running a zipper up and down quickly. Checked the fluid and there are miniscule bubbles in it; so small they are hard to see but it makes the fluid look cloudy. I looked at the obvious plumbing on the rack and don't see any leaks; where could the air be getting sucked in? I don't know much about how this thing is plumbed but what connections should I check?

Thanks in advance!

LS6427

iTrader: (2)

Do you have a factory power steering fluid cooler...?

They leak all the time....

.

71firebird400

Forgive my ignorance, but I'm not sure. The car is a 2000 Z/28; I do not see any lines heading towards the radiator or anything that appears to be a cooler. I will do a google search and get you a better answer.

_JB_

iTrader: (33)

Look on one of the radiator hoses for a silver pipe about a foot long. That's the stock cooler.

There's a picture in this thread: https://ls1tech.com/forums/pontiac-f...ng-cooler.html

71firebird400

Thanks for the picture! My car does not have the cooler. Must be getting sucked in at one of the lines between the rack and the pump, or one of the smaller lines on the rack itself. I assume that air can't get 'sucked' into the high-pressure side; is that a correct assumption?

Just to clarify; after the car sits overnight it is perfectly quiet in the morning. Not until I've been driving for 10 minutes or so does it start making noise. I believe it's leaking an incredibly small amount of air into the system.

wssix99

iTrader: (5)

Can you post some pictures? If air is indeed being sucked in, I'd expect your reservoir to overflow, which should come with a corresponding fluid level drop. If your impeller in the pump has broken, you could be seeing the effects of cavitation. http://en.wikipedia.org/wiki/Cavitation

How old is the pump and how many miles are on it?

The fluid is under much higher pressure than the outside air, so having air sucked in would be really difficult to do, unless its at the pump shaft seal. (I did have this happen to me on a failing water pump, as have had other members here but I haven't seen anyone post a similar problem related to the PS pump.)

GToe

maybe a line has a little leak

wssix99

iTrader: (5)

If that were the case, fluid (under pressure) would be squirting out instead of air sucking in.

LS6427

iTrader: (2)

^^^ True......it's not like a tiny coolant system leak where air can get sucked in during cooling.

Cavitation sounds like a possibility.

.

71firebird400

Pump is original to the car (2000) and has 125k miles. The noise gets dramatically quieter on gravel (when there is less load on the steering) and disappears each morning....only to return again as things warm up. What would you like pictures of?

wssix99

iTrader: (5)

I honestly can't remember what I was thinking when I asked that...


Lots of signs here that it could be the pump. I'd put a metal rod or mechanics stethoscope to it in order to confirm that's where the noise is coming from. If so, then its time for a new one or a rebuild of what you have.

71firebird400

Thanks. I think I'll give it a 'hail mary' bleed this weekend (wheels off ground; lock to lock 20 times) just in case but I know it won't do anything. I may invest in the Turn One pump; I've heard too much bad stuff about the rebuilt ones and hate how loud the stockers can be.

wssix99

iTrader: (5)

I called TurnOne and they did a great stock rebuild on my original unit and turned it around in a week with their custom pulley - no more PS pulley removers needed!

(I wanted a stock rebuild to keep pressure up for all my city driving.)

71firebird400

One thing I still can't wrap my head around is that it only makes noise after being warmed up. Hate to throw the time/money into a new pump and have it not fix the thing.

wssix99

iTrader: (5)

Does it only bubble when the fluid is warm and when its making noise?

ws6ta99

I have similar issue. The dealer had my car, went through two pumps, new hoses, power steering cooler. Noise still comes back after car is hot. It is quiet for a while, then gets noisy when hot. Embarrassingly loud. I have heard theories of pully/bearings and intake manifold sucking air when it gets hot. I will probably pull my car out of storage next week and dig into it again. If anyone learns or knows anything, please post up! Thanks!

71firebird400

Fluid does not "bubble"; there are extremely tiny bubbles held in suspension (they barely rise to the surface). Pump does not make any strange noises when not turning the wheel, only when I go to turn the wheel does the noise present itself. You can "feel" the noise through the steering wheel as though the air is causing the rack to cavitate. Very difficult to explain thoroughly, but definitely points towards something disturbing the steering fluid. Noise then dissapears once things are allowed to cool down; I believe this has to do with the bubbles making their way to the surface (but this is just a wild *** guess). No loss of fluid; haven't had to top it off in the year and a half I've had the new rack.

wssix99

iTrader: (5)

That's exactly the problem. Once gases separate from the fluid, it will give you an effect of a system that is not blead.


That would continue to point to the pump, but I'd first verify the noise is coming from it before doing a replacement/rebuild.