Power steering pump problem

[88K5DT]

Yesterday I installed a new power steering pump in my 88 blazer K5. The pump now makes a high pitched humming sound and worsens when wheel is turned all the way. Also when wheel is turned all the way it will make a loud pop sound. I am assuming I need to bleed the pump better but I am not certain?

 

[sandawgk5]

Yep sounds to me like the pump has air in it.

 

[88K5DT]

thanks!
Is it really bad to overfill the pump with fluid as some people say?

 

[R72K5]

well IMHO, with the cap removed i dont see how it could be bad, as all excess fluid will jsut fall out and onto ground anyways,

but.. maybe with the cap installed and too much fluid then POSSIBLY pressure may build up inside the reservoir when fluid is trying to return to it, and cause a problem,

maybe

mi not sure, as i am not a hydraulics/saginaw pump expert


dunno

someone here knows im sure, as i`d like to learn too

 

[dyeager535]

Well, for one thing, I've always been told/heard that turning the steering against the "locks" (extreme travel in either direction) is not a good thing, it puts a lot of pressure on the steering components.

I've overfilled a pump before, don't see how it could hurt unless the fluid somehow froths up and the pump is trying to push bubbles of air. I don't believe you need to worry about windage on these though, I've never seen power steering fluid (or Dexron used in a pinch) froth in a pump. The caps aren't a "tight" fit, they will easily spill/"vent" anything it needs to.

I'm interested to know how these things actually push fluid. Is it a vane pump like later auto trans pumps, or is it a gerotor setup like the engine oil pump? One thing I've not torn into is the power steering pump.

 

[diesel4me]

I disected a few..

I took a few GM pumps apart..they have vanes in them..some other makes use gear pumps,like a regular hydraulic pump on a tractor,only smaller...

One of the wierdest pumps I've seen was on a 1969 Lincoln Continental--with a 460 motor..it is made into the front of the engine!--behind the harmonic balancer,a gerarotor setup is made into the snout of the crankshaft!--and the P/S hoses screw into the timing cover! ---some 50's cars had the P/S pump driven off the rear of the generator,"piggy backed" together!..