hum/groan in steering column

Our 2002 Chrysler Town & Country minivan with 42K miles has an
occasional humming noise that seems to be coming from the steering
column. it is not audible once i step out of the van or when i raise
the hood to listen. Steering remains normal and turning doesn't
change
the sound, but the pitch does change when I accelerate. The sound
usually begins after driving for at least a half hour and then
stopping at a stoplight. I haven't had a mechanic look at it yet. I

just want to ask first if that sound is something to be concerned
about, or what to expect if I have a shop look at it. I would guess
it
would be hard for them to duplicate it.

 

My WAG - the brake booster is making the noise (acceleration => vacum
changes, noise starts when stopping at a stoplight). When DC boosters
go bad (and they do go bad), they make a high pitched whistling or
squealing noise that changes with application/release of the brakes.
Does putting varying amounts of pressure on the brake pedal change the
noise at all?

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

The biggest problem we are seeing at the dealer concerning P/S noises are
low fluid due to leaks at the cooler and the rack itself or just having the
old fluid flushed out and new fluid added. This noise is normally in the
morning or cold days.

Glenn Beasley
Chrysler Tech

 

On my 2003 (long out of warranty) I'm getting a hydraulic sound from the
steering after driving at high speed for long periods (hours plus Min of 75
mph). It's goes away after a some time of slow driving.
The dealer flushed the fuid after the first complaint and it seems to goawa
for a few months and now its back. It's happened again after a long trip and
it starting to be a little niosy all the time.
Is this the pump or the rack, or should flushthe fluid again?

Kevin