Slight give in steering but only for a few minutes

[N9nefingers]

So here's a problem that I've been having and can't seem to find anyone that's had this issue before. I have what I'll describe as a slight give in the steering of my truck across top dead center of my wheel, or 12 oclock. The wheel will just fall to 10 or 11 oclock then grab. But it'll only do it for a few minutes after start up and driving, then it's fine for the rest of the day. All steering components are new, the steering gear and pump are new but reman units. I've replaced the steering shaft with a Jeep one. The alignment was also just done. Other than the first few minutes of driving the steering is real nice and tight. Anyone have any info? Can point me in the right direction? Thanks guys.


1989 Chevy K1500 350TBI 5 speed No lift No crank

 

[N9nefingers]

Anybody? Ideas? Thoughts?

 

[east302]

With someone turning the wheel through this dead spot, how does the pitman arm react versus the steering shaft?

Was it doing this before replacing the steering gear?

I would think that a power steering pump issue would manifest with hard steering (reduced power assist) when cold, improving as it warmed up.


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[N9nefingers]

The pitman arm moves with the steering shaft. The steering acts almost as if pressure isn't built up in the system and that's what's causing the slip. Then after driving for a few minutes the pressure is where it needs to be and all is well. Is there a check valve of some sort in either the pump or the gear?

 

[east302]

The pitman arm moves with the steering shaft. The steering acts almost as if pressure isn't built up in the system and that's what's causing the slip. Then after driving for a few minutes the pressure is where it needs to be and all is well. Is there a check valve of some sort in either the pump or the gear?

The pump has a spring loaded flow control valve that will relieve flow back to suction if the downstream pressure is too high. Not sure about the gear internals.

If the steering shaft and pitman arm are moving in concert when this happens, to me that would rule out a gearbox issue unless, like you said, there is something internal that is temporarily restricting pump flow until it warms up.

I’m not sure if the TBI gives you better access than the vortec, but there is a metal screen on the end of the internal flow control valve where the pressure line connects. It may not hurt to pull it and see if it’s clogged or if the valve is obviously damaged, but at that point it may be easier to just pull the whole pump.

I suppose you could try flushing and bleeding it again. Maybe that pump flow control valve is sticking.

I guess if I was going to throw a part at it, it would be the pump.


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[N9nefingers]

Hey thanks for the info...that's what I wanted to know. Seems like something is temporarily stopping the flow just didn't know where. I'll give that pump a look. Thanks again for your help. I appreciate it.