User's Manual

PHASE I – VISUAL
INSPECTION
PHASE II – HYDRAULIC
SYSTEM TESTS
GENERAL
Phase I visual inspection procedures should reveal the most com-
mon problems found in a hydraulic brake system. The inspection
steps are presented in the order in which they are most easily
performed.
INSPECTION
1. Look for signs of fluid leakage at connection points as well as
around wheel cylinder calipers, the master cylinder and
hydrovac. Inspect disc brakes caliper piston boots for tears or
deterioration.
2. Inspect the master cylinder pedal and linkage for binding, bend-
ing or damage. Lubricate rotating and sliding components with
a rubber compatible lubricant.
3. Inspect the foundation brakes for proper adjustment and adjust
if necessary.
4. Start engine and have assistant make several brake applica-
tions while visually inspecting all hydraulic and vacuum lines,
hoses, and clamps for kinking, chafing, damage, corrosion and
signs of collapsing or "ballooning".
5. Remove the master cylinder reservoir cover and check the fluid
level. Refill as necessary. While the cover is off, look for discol-
oration, cloudiness, and "gumming" of the fluid. Also look for
corrosion on any part in contact with the fluid. If any of these
conditions are found, the system should be drained, bled,
flushed and refilled with the proper type of brake fluid for the
application. DO NOT MIX HYDRAULIC FLUID AND BRAKE
FLUID. "GUMMING" OF FLUID AND DAMAGE TO COMPO-
NENT SEALS WILL RESULT.
Federal Motor Vehicle Safety Standard #116 divides brake
fluids into three categories with the primary difference being the
fluid boiling points.
With the master cylinder cover off, have an assistant slowly make
a full brake application while observing the fluid in the reservoir.
CAUTION. Wear eye protection and do not allow fluid to contact
vehicle's painted finish. A small spurt or geyser at the beginning of
the brake application followed by continued fluid turbulence indi-
cates internal master cylinder leakage. Repair or replace. If the
fluid remains calm after initial spurt, continue to Phase II Testing.
Brake Fluid Boiling Point Boiling Point
Type Dry Wet
DOT #3 401°F 284°F
DOT #4 446°F 311°F
DOT #5 500°F 500°F
(silicone)
GENERAL
1. With the engine off and brakes not applied, install a 0-2000 p.s.i.
hydraulic gauge at the wheel cylinder or caliper and bleed air
from the gauge and its connecting line.
NOTES:
A. The gauge can usually be installed by removing the wheel
cylinder bleed screw.
B. When the vehicle is equipped with a dual or "split" brake sys-
tem, a gauge must be installed in each side of the system,
i.e.; one gauge in a front axle brake and one gauge in a rear
axle brake. Alternatively, the tests can be performed twice,
once for the front axle brakes and again for the rear axle
brakes.