No. 1503.1

USA
Advanced Technical Information
1503.1
4651
4
Clicking Noise From Front PCCB Rotors
Revision:		 This bulletin replaces bulletin Group 4, #1503, dated August 1, 2019.
			
Vehicle Type: 		
911 Turbo / Turbo S (991)
Model Year: 		
2014 to present
Information: 		
PCCB Rotors may be making a clicking type noise.
			
NOTE: The clicking noise in no way impairs the performance or safety of the braking system. The
			customer may continue to drive the vehicle without restriction. The clicking noise does not constitute a defect.
			
NOTE:
•
First perform thorough diagnostics of the suspension system. Suspension component 		
		
connections can cause this noise.
•
The information below is an aid in performing diagnostic measurements on the wheel.
•
		
Only submit a PRMS ticket if a root cause can not be determined after performing all 		
diagnostics available to you.
•
FTM involvement is the last option after all other options have been exhausted.			
			
			Due to tolerances on some of the parts connecting the brake disc to the mounting plate, small relative movements between these parts can occur. As a result, a clicking noise can be heard when the
brakes are applied at low speeds.
			The 991-II rotors have a slightly different design for the attachment of the rotor hat to the disc
(Starting in MY 2017). These rotors are retrofittable on the 991 generation I vehicles.
			Pre Checks
			
Wheels - Before rotors are replaced, it is necessary to check the
mating surface of the wheels with a straight edge (12” Starrett
380) to insure flatness of the surface. Imperfections in the surface
may have an influence on the rotor and cause noise.
AfterSales
November 6, 2020
Page 1 of 3
USA
Advanced Technical Information
1503.1
4651
4
Information
(continued):		It is necessary to check for flatness in about 6 different positions around the mating surface
(roughly every 60°), it is ok to do more than that, but not less.
			The mating surfaces at the outer and inner areas of the mounting circle need to be checked for
flatness. The recessed area in between (photo below) is not a part of the measurement.
Measure here
Not here
			Use a feeler gauge that is very thin. The .05mm thickness is probably going to be necessary to find
the uneven areas.
			
Record all measurements; make sure to include photos in PQIS.
AfterSales
November 6, 2020
Page 2 of 3
USA
Advanced Technical Information
Information
(continued):		
			
1503.1
4651
4
 enter locking wheel bolt - Insure that the center locking wheel bolt is properly lubricated in accorC
dance with WM 440519.
Insure that all mating surfaces are clean and free of debris.
			When torquing the wheel bolts, make sure the vehicle is off the ground. Use a torque wrench (that
is properly calibrated) in one sweeping motion, not an intermittent jerky motion.
			Replace the wheel only as a last resort.
			Rotors – The new rotor part numbers are listed below. They are also in PET.
			
991- II rotor part numbers:
			
			
			
			
Front Left Rotor: 991.351.407.06
Front Right Rotor: 991.351.408.06
Rear Left Rotor: 991.352.409.07
Rear Right Rotor: 991.352.410.07
			NOTE: Due to small design changes, 991- II rotors may not be an identical visual match to 991- I
rotors. This is considered normal and does not constitute a defect in workmanship or justify replacement.
Reference: 		
465119 Removing and installing front PCCB brake disc.
Warranty:		 Diagnostic time requires using separate time punches and detailed explanations of the
			diagnostics performed.
Important Notice: Technical Bulletins issued by Porsche Cars North America, Inc. are intended only for use by professional automotive technicians who have attended Porsche service training
courses. They are written to inform those technicians of conditions that may occur on some Porsche vehicles, or to provide information that could assist in the proper servicing of a vehicle. Porsche
special tools may be necessary in order to perform certain operations identified in these bulletins. Use of tools and procedures other than those Porsche recommends in these bulletins may be
detrimental to the safe operation of your vehicle, and may endanger the people working on it. Properly trained Porsche technicians have the equipment, tools, safety instructions, and know-how
to do the job properly and safely. Part numbers listed in these bulletins are for reference only. The work procedures updated electronically in the Porsche PIWIS diagnostic and testing device take
precedence and, in the event of a discrepancy, the work procedures in the PIWIS Tester are the ones that must be followed.
©2020 Porsche Cars North America, Inc.
AfterSales
November 6, 2020
Page 3 of 3