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90 sierra power steering box


junk_jivin38
07-26-2009, 09:53 AM
i have a 90 sierra 4x4 w/ 4.3 auto...got it last fall,and parked it...everything worked great,except the power steering,which had a blown hose and pump was about dry...recently towed it to garage(private,not repair shop)...i replaced the bad hose with a temporary 50 psi fuel line... 1st attempt-blew the line off the end...put it back on,double-clamped and torqued...now on jackstands w/tires off....topped off fluid,turned wheel back and forth,topped again,started engine and turned wheel again to bleed air,each time i turned the wheel the replaced hose moved in an arc...finally split the hose wide open...

questions are: what is the working pressure of the p/s system? 50 psi hose not enough?
am i looking at a new steering box?
is there a way to check the steering box for obstruction?
could the pump be overpressurizing from running dry?


it acts like the steering box is plugged...getting plenty pressure from pump,but when it hits that hose it seems to stop there...till the hose lets loose...
i have other issues to address,but this is one i've not seen before...i've owned several 1500's over the years and done all my own work,but never seen this before...any suggestions greatly appreciated! Thanks

2000CAYukon
07-27-2009, 02:58 PM
The high pressure side of the pump can go pretty high, 800 - 1000 PSI so you should use a proper replacement hose for the high pressure hose.

If the pressure is too high, the pressure relief valve could be bad or the gear box is plugged.

//2000CAYukon

junk_jivin38
08-05-2009, 04:02 AM
thanks for the info....kinda figured that hose wouldnt work...

question now is how can i test the steering box and/or pump to determine if there is blockage?

i dont wanna put in a new hose just to have it blow apart...i have a used steering box off a z-71 out in the yard,but would rather not go through replacing it unless i know its bad...remember,the high-pressure hose was blown when i got the truck

2000CAYukon
08-05-2009, 08:44 PM
thanks for the info....kinda figured that hose wouldnt work...

question now is how can i test the steering box and/or pump to determine if there is blockage?

i dont wanna put in a new hose just to have it blow apart...i have a used steering box off a z-71 out in the yard,but would rather not go through replacing it unless i know its bad...remember,the high-pressure hose was blown when i got the truck


You need something like this to really troubleshoot power steering pressure problems: http://www.etoolcart.com/powersteeringpressuregaugehoftu22a.aspx

//2000CAYukon

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