Power Steering working only sometimes?

[absintheisfun]

I'm guessing that my pump is failing, but would like to ask some of the more knowledgeable folks here before I replace it for possibly no good reason.

There is zero power assist at idle, but if I get up over 1000 RPM I get full assist. It's an 04 Silverado,A tech buddy of mine at the dealership I work at says that the racks on these things are bulletproof and he has never seen one fail.

Thanks for the help!

[oestek]

It sounds like the bypass valve is stuck. I'm guessing it's a Saginaw pump - they still use a variant of the old p pumps in some trucks. Check out this link to see the valve - sometimes you just have to take the fitting off and pull the valve out, make sure the o-ring is happy, and that there is no burrs or garbage hanging up the valve.

http://www.pozziracing.com/camaro_steering.htm#PS%20pumps%20and%20brackets

[absintheisfun]

got an early start today (Cowboys game started at noon, so I had a deadline!). It was the pump. Swapped a new one on and it works like a charm!

[David Pozzi]

What I have read is. If a pump goes out, and you don't flush the rack, then metal from the pump failure will take out either the rack or the new pump. Might take a while but there's likely metal in the system now.
Adding an inline filter might help. A lot depends on exactly what the pump failed from.
David

[monteboy84]

We had a similar problem on our late model stock car, but the fix was only temporary by by replacing parts, the problem only completely went away when we installed a Magnefine filter in the low pressure return line, as alluded to by Mr Pozzi. Even if it's working fine, the filter would be good for the system anyway.

I know there was also a fluid replacement needed on a lot of those trucks, but that was mainly in cold weather, the fluid would foam up.

-matt

[John Wright]

Were your brakes hard to use as well?(before the pump replacement)