For 1990-2009 cars

# VACUUM REGULATOR VALVE SERVICE REPLACEMENT

#### MODELS AFFECTED: 1984 CENTURY, REGAL, LESABRE, ELECTRA & RIVIERA WITH 3.0L, 3.8L & 4.1L ENGINES

Figures A & B show both first and second type EVRV's. The EGR vacuum diagnostic control switch shown in Figures A & B is serviced separately. Should the diagnostics procedure lead to the replacement of this switch, Part Number 25519370 listed in Group 3.670 should be ordered.

The filter for second type valves (Figure B) will also be serviced by Part Number 25520267 listed in Group 3.670 beginning approximately Novmber, 1983.

If service of the filter is required on type 1 EVRV's (Figure A) the complete valve assembly must be replaced.

Second type EVRV's (Figure B) went into production beginning October, 1983. Recommended service interval on the EVRV filter assembly is 30,000 miles.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.