I just purchased a complete power steering rebuild kit from VBP. The kit comes with rebuilt control unit, piston, and new hoses. My question is: what are the tricks to get the air out of the system after installing the new parts?

 

I just raise the front wheels off of the ground, make sure the pump is full of fluid and slowly turn the wheels left to right, lock to lock about four times . Works for me.

 

I agree. I rebuilt my system just to freshen it up due to age. All that should be needed is to fill the system & cycle it from stop to stop slowly with engine running. Check the fluid level after each cycle and after the level stops dropping you've got all the air out. The system is good about purging it's self of air.

 

I recommend that you stroke the system full lock to full lock with the wheels in the air and the engine OFF. Since you are starting with a new assist cylinder it will be filled with air. You may need to do the lock to lock turns a couple dozen times before air bubbles stop rising in the pump reservoir. Refill the pump reservoir as the oil replaces the air and the oil level drops.

With the engine off, the assist cylinder will act as a piston pump. It will move the oil and large air bubbles through the system.

If you start the engine with large quantities of air in the system, the air gets pushed into the pump where it is whipped with the oil into a froth. Some people report that their pump overflows when they start up the engine. Foam takes up a lot more space than plain oil. Foam in the system also makes for very erratic power assist. The very small bubbles in the foam will eventually work their way out after a couple days of driving and sitting.

Don't even think about trying to balance your control valve until all the air is out of the system. If you try to balance it with air or foam in the system you will only be doing it again later.

BTW, I also recommend that you fill the system with genuin GM power steering fluid. It is the only fluid that is specifically formulated to operate with the Saginaw power steering pumps. The fluid is available at GM dealers.

Jim

 

Thanks for the info. The control valve is supposed to be pressure tested and zero balanced. It should arrive today.

 

Just to be safe!!!! After getting the air out and you are ready to start your engine for the first time:

At this point, NEVER, NEVER, NEVER reach through the steering wheel rim to turn your ignition key to start your engine. If by some chance the valve was not correctly balalanced, after engine start the valve has been known to whip the steering wheel all the way to full lock. Some people have reported a badly bruised forearm from the steering wheel spoke hitting them.

This may never happen with your valve, but it pays to play it safe.

Jim

 

True statement. I've been told the same thing over the years. Never seen it happen though.