C 3500 Truck 2WD V8-305 5.0L (1986)
Brake Caliper: All Technical Service Bulletins
Brake - Pulsations
Number:
86-84
Section:
5
Date:
May, 1986
Subject:
BRAKE PULSATIONS
Model and Year:
ALL MODELS
TO:
ALL CHEVROLET DEALERS
Brake pulsations are normally the result of uneven rotor thickness or an out of round condition in a brake drum. Pulsations can also
be caused by a rust build up on the rotor. Under certain conditions, the exterior of the rotor may rust. This would normally not occur
unless vehicle was parked for a few days and corrosive conditions were present. If the rotor exterior does rust, the area under the
brake pads usually remains rust free. The difference in friction between the rust and unrusted areas can cause pulsation for several
stops, but will improve as the linings scrub the rust off the rotor.
Normally, two or three stops will return the system to normal. Under adverse rust conditions, as many as five or six stops may be
required. Usually this condition will correct itself. It is, however, important that the customer understand what is happening should
you receive a comment on this condition.