Measuring The Brake Disc Thickness Tolerance - Porsche 996 TT Repair Manual

• Lateral runout of the removed brake disc: max. 0.03 mm!
Wheel hub lateral runout: max. 0.03 mm!
•
• The permissible lateral runout of the installed brake disc is max. 0.06 mm!
• Do not damage the brake hoses or brake lines during removal/installation of the brake caliper!
5. If the brake disc lateral runout exceeds 0,06 mm, mark the position in relation to the wheel hub and
remove the brake disc. Check the wheel hub lateral runout.
6. Check the wheel hub lateral runout as described below: Measure 1 x outside −arrow− and 1 x
inside −arrow− of the wheel bolt area (5−point measuring procedure) on the front face of the
wheel hub. Fasten the dial gauge using a commercially available universal dial gauge holder (refer
to Workshop Equipment Manual, Chapter 2.4, No. 147−1).
Wheel hub lateral runout is too large:
Replace the wheel hub.
Wheel hub lateral runout OK:
Clean the levelling and centring surfaces on the brake disc and wheel hub. Next, apply a thin coat
of Optimoly TA to the centring surface on the wheel hub. Fasten brake disc on the wheel hub in a
different position than before
measurement with adapter plate 9510/1 fitted. If the lateral runout is still greater than 0.06 mm,
replace the brake disc.

Measuring the brake disc thickness tolerance

Measure the brake disc thickness deviation within the brake surface at approx. 8 points by using the
micrometer. Thickness tolerance of the brake disc max. 0.02 mm (new condition: max. 0.01 mm).
996420, 996421, 996450, 996451, 996620, 996621, 996650, 996651
Measuring the front brake disc lateral runout
einordnung
radially offset with respect to the wheel hub. Repeat the
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