Somerset V6-181 3.0L (1986)
Vacuum Reservoir HVAC: Customer Interest
HVAC Vacuum Reservoir - Noise
Bulletin
87-6-18
Date
Aug. '87
Ref.No. 87-164-6
Corp. Ref. No. 771206
SUBJECT:
HVAC VACUUM RESERVOIR NOISE
MODELS AFFECTED: 1986-87 SOMERSETS AND SKYLARKS
Subject vehicles built prior to February, 1987 (below VIN HM051662) may exhibit a noise condition similar to a steering stop or bushing squawk. This
noise may be deceptive in that it can be quite loud and appear to be coming from the dash panel area of the car. The noise is actually the check valve and
diaphragm inside the HVAC vacuum tank located on the right end of the HVAC case in the passenger compartment.
To diagnose the condition, with the engine running, operate the A/C control through its modes and listen for the noise. If the noise is present, then
disconnect the vacuum source from the vacuum tank. The reservoir should hold vacuum for at least one mode change. If the reservoir leaks down or it is
quiet when mode is changed, then replace the vacuum tank assembly.
The noise may be described as a whistle, a moan, a squawk, a hiss, a vacuum leak or a squeak. The correction is to replace the vacuum tank assembly
with a service replacement, Part Number 10000669, from GMSPO.
WARRANTY INFORMATION
Labor Operation Number:
D1740
Labor Time:
0.3 Hours
Trouble Code:
92
