Hello new to the forum and have done several searches regarding my issue.

1997 K1500 with EVO power steering; replaced the pump last week due to light hissing during operation but worked fine (old pump), really wish I hadn't. Replaced the pump and bled system using lock to lock method, and new orings etc.

1st pump (A1Cardone), 2nd pump in a week and I am getting knocking noise from that pump also (AC DELCO), little or assist at idle and when knocking starts it continues to escalate with RPM.

It will work fine for 5mins until engine is warmed up, then total crap!

Pulled the serpentine off and no noise at rpm (definitely the PS pump). Apparently the EVO has been deleted from GM and others have deleted it with 1996 and older pressure valve and pressure line. I have these and will probably install tomorrow for the (4th time pulling the pump out this week).

Seems funny that the EVO valve went bad upon pump replacement, something else is going on and I can't figure it out!

Really tired of pulling it apart,

Please help, and thanks...

BD

 

I had a similar problem on my 96...found a partialy collapsed pressure hose. I would only collaps after it warmed up. Just a thought. You're probably right re: the valve.

Charlie

 

Well the pulley wasn't pressed on quite far enough and the belt was slapping (sounds like a bearing in the pump). Still lose pressure/assist at idle after warm. Omitted the EVO and used the 96 pressure line, no real difference. It works but after a few cycles lock to lock I lose 75% of assist. POS!

Probably going to have LEE Powersteering build a custom pumpm (Not cheap) with increased assist at idle and alter the valve in the box or maybe the pump for more road feel. Maybe the fluid is contributing (ATF) too thin?

Pressure fitting is leaking at the back of the pump, torqued it to 45ft/lb? spec is 37-55 might try to tighten a little more?

not pulling the pump again unless somebody offers a solution or it takes a complete Dookie, or gets a lot worse!

Thanks for the help, SS.

 

I would flush out the system and put a a pint of Lucas Power Steering fluid in( It's thicker) and top off with a quality power steering fluid such as Quakerstate ,Castrol,ect.

Is the belt routed correctly? I would look for the simple things first as we all over look the "dumb stuff" in our haste to complete the job. Just some thoughts...

Charlie