'99 Grand Cherokee Limited - high pitched whistle

I need some assistance. About a month ago, my JGC began to make a high
pitched whistling sound. At first, it was intermittent and not very often.
Now, it occurs frequently and continues for several minutes, although it is
still intermittent. The whistle seems to be coming from the brake pedal.
When the pedal is depressed, the whistling seems to stop. What in the world
is going on and is it dangerous? Thanks in advance.

Ellie Rose did pass the time by typing:
> I need some assistance. About a month ago, my JGC began to make a high
> pitched whistling sound. At first, it was intermittent and not very often.
> Now, it occurs frequently and continues for several minutes, although it is
> still intermittent. The whistle seems to be coming from the brake pedal.
> When the pedal is depressed, the whistling seems to stop. What in the world
> is going on and is it dangerous? Thanks in advance.

Could be a few things including a leaking break booster. Worst case you would
be left with standard brakes but it takes a looooong time and eventually the
whistle will sound like a diesel trucks air brakes.

You can test the booster with a small vac pump, just remember do NOT exceed
14" of vac, just pull it down to 10" or so and watch. If the needle creeps
up it's leaky and needs to be replaced.

http://www.tooldesk.com/products/pro...il.aspx+id+986
That's the overblown metal one, the plastic version is just fine for
the garage and is about $10 at most auto parts stores.

Have you cleaned the throttlebody and the idle air passage? Just putting
on the brakes changes the idle air motor and could make a whistle. Thing
is whistles are hard to locate.

--
DougW

I know you said brakes related ... but here's a thought ... my old
heating/cooling fan whines a bit now and then in winter on low speed. No big
deal ... yet :-)

"Ellie Rose" > wrote in message
hlink.net...
> I need some assistance. About a month ago, my JGC began to make a high
> pitched whistling sound. At first, it was intermittent and not very
often.
> Now, it occurs frequently and continues for several minutes, although it
is
> still intermittent. The whistle seems to be coming from the brake pedal.
> When the pedal is depressed, the whistling seems to stop. What in the
world
> is going on and is it dangerous? Thanks in advance.
>
>

Check your vacuum lines on the driver side of the engine. Vacuum pulling
through a line will whistle too.

--
HarryS My 2¢
"Ellie Rose" > wrote in message
hlink.net...
|I need some assistance. About a month ago, my JGC began to make a high
| pitched whistling sound. At first, it was intermittent and not very
often.
| Now, it occurs frequently and continues for several minutes, although it
is
| still intermittent. The whistle seems to be coming from the brake pedal.
| When the pedal is depressed, the whistling seems to stop. What in the
world
| is going on and is it dangerous? Thanks in advance.
|
|