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Service bulletin GRP4/9310

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id39626
Published by NHTSA1995-11-01
Manufacturer's numberGRP4/9310
Manufacturer's date1993-08-01
NHTSA componentSERVICE BRAKES, HYDRAULIC:FOUNDATION COMPONENTS

NHTSA's summary

BRAKE VIBRATION DAMPER APPLICATION - NEW DAMPING PLATE WITH STEEL CLIP. *TW

The document

No address for NHTSA's copy can be built for this communication. Ask the dealer for it by the manufacturer's number.

Components

Brakes

Vehicles listed
PORSCHE 9111989, 1990, 1991, 1992, 1993
PORSCHE 9281988
PORSCHE 9281989, 1990, 1991, 1992, 1993
PORSCHE 9441987, 1988, 1989, 1990, 1991
PORSCHE 9441992 to 1993
PORSCHE 9681992, 1993

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Recalls for the same vehicles and component
19940051994-01-13. Brakes
93V2050001993-12-07. SERVICE BRAKES, HYDRAULIC:POWER ASSIST:VACUUM:HOSES, LINES/PIPING, AND FITTINGS

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
No. 1801.42022-04-05. Service bulletin. Advanced technical information for a brake squeal.
ATIALL416052021-06-28. Service bulletin. Understanding and addressing brake squeal complaints.
122-L5E2R-042018-04-23. Service bulletin. Subject: Replacing brake booster during repairs Information: If the brake booster on the 911 Carrera 2/Targa/Speedster (964) needs to be replaced, the replacment brake booster will be a 911 (993) version. During conversion, the brake master cylinder, mounting saddle and (push rod) joint screw must be replaced (? Figure 1). The power steering pressure and return linesmay also have to be replaced.