Noise,
no power assist and leaks are some of the most common reasons for power
steering pump replacement. But what are the root causes of power steering
failures that lead to a replacement?
The
most significant causes are system contamination, improper pulley installation,
and using the wrong fluid. Following the recommended service procedures during
power steering pump replacement addresses these root causes and helps ensure
the longevity of the new power steering pump while reducing the chances of
premature pump failure.
Flush the System
Flushing the system will
help eliminate any residual contaminants from causing future pump failure.
Dirty or contaminated fluid may cause low or no pressure from the power
steering pump, causing the relief valve to stop functioning. Use the proper
special tools (if applicable) to flush the system. Always follow the
manufacturer's specific instructions on flushing, but remember the following:
·
Flush out the power
steering fluid in the lines before removing the old pump
·
Flushing may require two
or more quarts of OE-approved power steering fluid
Pulley Removal and
Installation
Remove the pulley from the
power steering pump using the proper special tool. Using the correct power
steering pump pulley remover will help prevent distortion of the pulley, which
could damage the bearings on the new pump. Pulley alignment is crucial to
proper pump operation and belt longevity.
During installation of the
pulley onto the new pump's driveshaft, use the installation tools that are
included with each replacement pump or the pulley installer special tool.
Proper pulley installation and alignment are vital for reliable pump operation.
Never use a hammer to install the power steering pulley. Also, the face of the
pulley hub must be flush with the end of the pump driveshaft. (Fig. 2)
To ensure exact pulley
alignment, use a laser alignment tool that mounts to each drive pulley to check
the pulley next to it. Any distortion or misalignment can be easily identified.
New O-rings
Use the new O-rings
included with the new power steering pump. Re-using old O-rings can lead to
leaks. The new reservoir O-ring must be lubricated with OE-specific power
steering fluid prior to installation. Lubricate the control valve O-ring prior
to installation as well.
Position the control valve
O-ring in the proper groove. (Fig. 3, A) It
should not be in the groove with the pressure bypass hole. (Fig. 3, B)
Power Steering Fluid
Check the specific
manufacturer's Service Information for the correct fluid to use. Different
fluids are specified by the manufacturers to meet the operating requirements of
their power steering systems.
ACDelco power steering
fluid part numbers are: 1 quart - #10-5030; 1 pint - #10-5031. (Fig. 4)
On some modern steering
systems, brake fluids or transmission fluids may not be compatible with pump
components. Using the wrong fluid could cause hose and seal damage as well as
fluid leaks.
Keep in mind that
regardless of the original color of new fluid that all fluids will darken in
color during use. Fluid color is not an indication of fluid condition.
Bleed Air Out of the
System
Finally, after servicing the
steering system, always bleed the air from the system and verify proper system
operation. An accurate fluid level cannot be obtained unless air is bled from
the steering system. The air in the fluid may cause pump cavitation noise as
well as pump damage over a period of time.
-
Thanks to Mike Militello
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