96 Impreza power steering gone/weak after pump rebuild

[lowbreaker]

*Tried searching forums for anyone with a similar problem/solution and couldnt find it, sorry if i overlooked one*

PS pump on my girlfriends 96 Impreza EJ22 was leaking pretty bad so i resealed the whole pump with a factory reseal kit while i had it apart. Otherwise PS was working fine and not making any noises. Got it back together and it took a minute to work all the air out after reinstalling but otherwise it was working great for the first day/10 miles of driving. Next day the gf said the ps wasnt working and sure enough there was practically no power in it at all. if you hold pressure against the steering steering wheel to one side you can feel the pump very weakly trying to kick in and turn the wheels ever so slowly, but realistically it might as well be doing nothing at all while you're driving.

Popping the hood i see that the PS pulley is spinning fine, belt tension is good, and theres no noises, vibration, leaks, or bubbling inside the resevoir. In fact, i look inside the resevoir with the pour filter removed and the fluid doesnt appear to be moving at all, its just totally still except when someone is actively turning the wheel for me - then i see movement in the fluid, and still no bubbles.

I removed the pump and broke it down again to see if i could notice any glaring issues...shredded rubber, metal shavings...obviously misinstalled or missing vanes? everything looked totally fine. Vanes where definitely installed correctly - round side out.

one thing i noticed was that the pulley did not turn very freely. i could spin it by hand but there was definitely resistance - both before and after my second time tearing down the pump.

Is that normal? should the pulley spin easily and freely - whether it's dry or filled with PS fluid?

Another concern of mine is that I allowed dirt or old o-ring crumbles to fall into the pump body on the initial reseal attempt, and maybe a valve is clogged somewhere down the line? anyone have pointers of where or how to check beyond cleaning the body out?

any info or pointers are appreciated! 

 

[idosubaru]

Where was the old pump leaking? Front seal, rear gasket or reservoir oring? 
And how badly was it leaking?

I assume there’s a new oring between the reservoir and pump body?

Are you sure it was totally bled of air?  I’m suspicious if more air was introduced? Seems unlikely for sure, but hate to diagnose a pump or valve body without checking. 

I’d be tempted to toss a used one on to differentiate between pump or some other issue.  I don’t think I have any 90s pumps left. 

[lmdew]

I have several used pumps.  $20 + shipping.  Flat rate Large box.

[lowbreaker]

Mostly was leaking from resevoir o ring, though potentially the the main gasket as well. 
Did the rebuild because there’s oil leaking on exhaust and trying to track down what’s all causing that. There was def PS puddles on top of engine.

im about as sure as one can be? I know when it definitely was not bled or air because of the loud obvious  noise the pump was making ans all the turbulence/foaming inside the resevoir.  None of that is present now and again, by all appearances inside and out the pump Functioning fine.

and remember, the first day or so after initial rebuildthe PS was operating perfectly fine.

today driving the impreza with my gf she remarked it felt like the PS was getting stronger and i reached over (parked) to turn the wheel and it did feel much more functional.

She’ll continue driving it and maybe just some gunk stuck somewhere? 
still curious to hear ppls ideas tho!
i really don’t enjoy problems mysteriously solving themselves, ha. 

[heartless]

i know it is a very different pump/setup, but we had to replace the ps pump on the other half's 06 Outback.. that was a pain in the backside to get all the air out of that one..
turns out, he had buggered an o-ring on the return line when reassembling everything and it was sucking air into the system.. once he found that and replaced it, it bled out fine...

but the instructions for bleeding it were very specific in stating that after the initial bleeding, to let it sit for 4-6 hrs, and do it again to make sure all the air is out.

Edited October 19, 2021 by heartless