buzzing noise coming from front usually while braking

[GPdriver1986]

I have a wierd buzzing noise that I hear usually when I push on the brake could it be this:

 

RATTLE/BUZZ NOISE FROM I/P DURING BRAKE APPLY/RELEASE #92-5-12 - (01/24/1992)

Subject: RATTLE/BUZZ FROM INSTRUMENT PANEL DURING BRAKE APPLY/RELEASE (INSTALL NEW VACUUM CHECK VALVE)

 

Models Affected: 1990-91 TRANS SPORT 1988-92 GRAND PRIX MODELS ----------------------------------------------------------------------------

 

This bulletin has been revised to clarify the application and add the Grand Prix model. This bulletin cancels and replaces bulletin 91-5-6 issued 2/91. Please discard bulletin 91-5-6.

 

Condition:

 

---------- Some 1990-91 Trans Sport models may experience a rattle or buzz type noise which seems to come from the instrument panel area in front of the driver.

 

In addition, some 1988-1991 Grand Prix models with J65 brakes and all 1992 Grand Prix models may experience rattle or buzz type noise which seems to come from the instrument panel area in front of the driver.

 

Cause:

 

------ A vibration in the vacuum check valve on the power brake booster.

 

Correction:

 

----------- To eliminate this noise, a revised vacuum check valve has been released. This new check valve is on all vehicles built after VIN breakpoint MT210360 for the 1990-91 Trans Sport.

 

For vehicles built prior to these breakpoints, and for 1988-92 Grand Prix models install a new vacuum check valve and rubber grommet kit, P/N 18018978.

 

Parts are currently available from GMSPO.

 

TRANS SPORT GRAND PRIX

 

Labor Operation Number: H1240 T1812

 

Labor Time: 0.2 Hour 0.2 Hour