power steering hissing
 

ok guys, who knows what's up? i have a hissing noise for about 10 seconds after start up and every time i tap the gas after that. i've isolated this hissing noise to the power steering pump/resivoir area so i figured o-ring, but that did not fix it. i'm not losing any fluid and the level seems good. next replaced both belts and tensioner bearings, still no relief. i'm not sure how to tell if the pump is bad, any ideas? also the pump pulley seemed to spin smooth by hand, with no play. i'm going to add more fluid to see if that might help. should i try the o-ring again? i don't have bubbles in the tank does that mean o-ring is good? please give me your 2 cents, cause i'm out of ideas. thanks.

Use a piece of tubing as a stethoscope and see if you can pin it down more closely. Possibly a leaking valve within the rack assembly. :confused:

find out soon, three days ago mine was making noise then it went all tohgether, there was power steering fluid all over the engine, but the resivior (cant spell) was full:eek: so i start it back up and the belt burned off because the pump had completly locked up, so no alternator either, luckly i was close to home:D

I have replaced the O-Ring before and still had problems with it. I found that sometimes the O-Rings at the pressure switch are bad as well. The switch is on the line under the tank and 2 wires come off of it. Be very careful if you work with it, because the wires break off very easily. That may be the problem, unless the pump is bad. I have not heard of many pumps actually going bad. They are usually replaced instead of doing the O-Ring fix. Let us know what you find out. :)

well, i used a real stethoscope to narrow it down the first time, i guess i could take the head off the scope and get in there further. this really makes me cringe though, this car has already ate my right index finger a couple years ago messing around the belts while it was running, i'll just tell my wife you told me to..HAHAHA!

oh, one more thing before i go get my face sucked into engine. wouldn't there be some kind of leaking if this was air sucking in through an o-ring? hey nightrider, do you know what caused/symptoms yours was presenting before...before....well you know what, we just won't say those bad words anymore.

well a few symtoms i noticed were no power steering under 1200 rpms, and it would be hard, then soft, then hard then soft, ect, ect, as i turned the wheel, and once in a while it would sound like an angry hornets nest when i was sitting at idle with the wheels straight

ok, good news/ bad news and more bad news. good= i still have my face and..well...9 1/2 fingers still. bad= filled resivoir to top, no change. repaced o-ring 2 more times, no change. poked around with a more specific tip on my stethoscope, seems like sound is coming from resivor, not so much pump block, not pulley, not hoses/fittings going in to res. so naturally i was thinking o-ring still which is why i replaced it 2 more times. so if it's the o-ring sucking air would there be bubbles in the tank though? is it possible i did this wrong 3 times?

An O ring is properly used when in a fitting, whereby the ring is constrained on all of four sides, across flat surfaces so that it expands into a limited free spaces, and therefore is maintained under constant pressure, in all of four directions.

The troublesome O ring is fitted in an application which correctly requires a gasket which can be compressed in only one direction. With nothing stopping radial expansion, the ring expands and flattens to the extent that sealing pressure is lost. This was bad engineering by Subaru. :(

Consider these aspects and make sure the O ring is being compressed so as to make an airtight seal against smooth clean surfaces. If in doubt, make yourself a gasket from some suitable impervious, compliant material to ensure a proper seal. ;)

Such a gasket might be a good stock line for on of our commercial members. :)

P.S. When mine was leaking there was no visible evidence in the form of bubbles or frothing.

When my p/s pump went...
 

...it was basically a catastrophic failure, i.e. fluid blown out through the front bearing/seal assembly behind the pully. Other than the 15 year age I truly believe it was related to the previous crank pully failure and the resulting strain it must have imparted to the p/s pully & shaft.

As previously indicated the lifetime guaranteed p/s assembly from Rockauto.com was a direct replacement but does not include the "connector", the switch, reservoir, cap, screen, etc. but does include a couple packages of O-rings. Mine works very well and would seem to be appropriate for both types of p/s systems. From all that I can determine the material differences are in the rack assembly itself, none are on the top of the engine.

Cheers!

hey good idea trevor, a gasket. you think i could try like gasket sealer RTV? or could that have negitive effects if it dissolves in the pump?

I'm not convinced that your O ring is the actual issue here. It "sounds" like the PS pump itself is freaking out. If you indeed had a leak where air is going in, wouldn't there be fluid leaking out? Furthermore, if your res is sucking in air and then pumping it throughout the PS system, wouldn't you be experiencing cavitating and subsequent loss of power steering?

I believe I have the same sound you're experiencing and waiting for the PS to take a total dump. If this unit is rebuildable, then perhaps I should look into it. My only real indication was when I lost steering effort below 1500 rpm on couple of occasions. The rack has been rebuilt so that's eliminated.

Just thinking out loud...

alia, you got my sound too? hissing when you start up for about 8 seconds, no hissing when idle, continuous hissing when throttle increased even a lil' bit, and hissing when a/c on(prob. bec/ idle goes up) i can't really hear it from in the car, but with the hood open there's no mistaking it.

The noise due to air in the system, as a result of the O ring leaking, is usually dependent on the pump exerting pressure, e.g. when the steering wheel is turned, car stationery, engine running. In my case it was more of whine than a hiss, and more than likely involved a valve chattering on its seat, due to bubbles of air within the fluid.