900 L4-1985cc 2.0L DOHC (1986)
Brake Rotor/Disc: Technical Service Bulletins
Brake Rotors - Resurfacing/Replacement Guidelines
FILE IN
VOL.
S.I. Man.
I
SEC.
PG.
A-5, B-5
34, 3
Issue:
11/89-1190
Subject:
Brake Rotors, Resurface vs. Replace
Application:
All 900 and 9000 Models
Brake rotors we often replaced needlessly even though they we within specified service limits. Unnecessary rotor replacement results in excessive
warranty and customer costs. Likewise, imprecise machining may result in excessive costs by causing repeat repairs or shortened rotor life. This bulletin
provides guidelines for:
^
Determining when a rotor should be resurfaced
^
Determining when a rotor should be replaced
^
Proper resurfacing techniques
When deciding whether to replace or resurface, the first step should be to visually inspect the rotors for severe heat and other damage. Measure the rotor
thickness and lateral run-out. On 900 models, the hubs may also need to be measured for lateral run-out.
An on-car brake lathe is the best method for refinishing brake rotors. On-car lathes resurface the rotor while compensating for any variation that may
exist in the wheel hub, wheel bearing, or brake rotor. Off-car lathes often machine-in variations that do not exist on the car because of imprecise
centering of the rotor on the lathe.
Figure 1 - Measuring Brake Rotor Lateral Run-out.
Tools Required:
Brake rotor micrometer (with conical anvil)
Dial indicator and fixture
On-car brake lathe (self-powered or vehicle-driven)
Wire brush
