On Tue, 5 Jan 1999, Henning, Eric wrote:
> hear a faint hissing noise (vacuum?) coming from under the dash (brake
> booster?).  Will not hear again until the next morning.  Is this a bad
> sign or did my hearing just improve 1000% and this is normal noise.
>
> eric.henning@bailey.com

i'm probably wrong, but i think that you might have a small leak in the
master cylinder cap and when the brake fluid is sitting in the morning and
you use your brakes it sucks in a small quantity of air from under the
dash, but when the van heats up, the part expands and the leak is sealed
until the van cools down completely... just my $.02 worth

Sudhir H. Desai          1984 VW Vanagon 3.4 liter Chevy V-6
desa4622@kettering.edu   sudhir_desai@geocities.com
ICQ# 17014903 & 8255956  http://www.geocities.com/MotorCity/Speedway/1889
Purgatorio, Canto XI, lines 1-24