# No power steering after gearbox replacemen



## busaben (Oct 30, 2008)

Alright guys, I have a 67 Lemans with hydro boost from a 76 caddy and a Jeep power steering box. I replaced the steering box due to leaks, topped the fluid, started it up, turned the wheels and topped the fluid again, all worked as it should. Two weeks later I go to drive the car and the steering is horrible, almost can’t turn it. 

I jacked the front end up today, turned the wheel a few dozen times with the engine off, then again with the engine on, still extremely hard to turn when running. I’m at a loss, only other thing I know to do is use a vacuum pump on the hydro boost return line to possibly suck any air out. 
What happened?


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## O52 (Jan 27, 2019)

Flow valve is stuck inside the pump. Remove high pressure hose and tap the valve with a 6" extension. It's spring loaded and should pop out. Then clean pump and reservoir and completely flush your system with Delco Power steering fluid. 
Doesn't take much dirt or debris to cause the valve to stick. I had a dog hair in mine. 
I've also had rebuilt pumps that the flow valve bore was slightly oversized causing the flow valve to become cocked inside.


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## busaben (Oct 30, 2008)

Thanks!! I have a few questions though, do I tap inside the pump? I’m not sure where that valve is, Does it matter if I unhook the high side from the gearbox or pump side? I’m guessing it’s to depressurization the pump. I’ll give it a try next off day. I also plan to add a filter on the return line.


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## O52 (Jan 27, 2019)

Pressure side. remove the hose and the valve should just pop out. But occasionally they stick in the "Bypass" position (no assist to gear). 
For a good overview of the GM power steering system, read the Jim Shea Steering Papers. 

BTW. Make sure the valve goes back in with the nut and screen first. O ring to the rear.



Jim Shea’s Steering Papers


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## busaben (Oct 30, 2008)

Forgot to share the fix, turns out that the replacement steering box was at fault. Replaced it again, bleed it, now all is well


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## O52 (Jan 27, 2019)

Good to know, thanks for the update.


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