Dodge 2000 DURANGO Service Manual page 165

DN
DIAGNOSIS AND TESTING (Continued)
Swollen rubber parts indicate the presence of
petroleum in the brake fluid.
To test for contamination, put a small amount of
drained brake fluid in clear glass jar. If fluid sepa-
rates into layers, there is mineral oil or other fluid
contamination of the brake fluid.
If brake fluid is contaminated, drain and thor-
oughly flush system. Replace master cylinder, propor-
tioning valve, caliper seals, wheel cylinder seals,
Antilock Brakes hydraulic unit and all hydraulic
fluid hoses.
SERVICE PROCEDURES
BRAKE FLUID LEVEL
Always clean the master cylinder reservoir and
caps before checking fluid level. If not cleaned, dirt
could enter the fluid.
The fluid fill level is indicated on the side of the
master cylinder reservoir (Fig. 9).
The correct fluid level is to the FULL indicator on
the side of the reservoir. If necessary, add fluid to the
proper level.
Fig. 9 Master Cylinder Fluid Level - Typical
1 – INDICATOR
2 – RESERVOIR
MASTER CYLINDER BLEEDING
A new master cylinder should be bled before instal-
lation on the vehicle. Required bleeding tools include
bleed tubes and a wood dowel to stroke the pistons.
Bleed tubes can be fabricated from brake line.
BLEEDING PROCEDURE
(1) Mount master cylinder in vise.
(2) Attach bleed tubes to cylinder outlet ports.
Then position each tube end into the reservoir (Fig.
10).
(3) Fill reservoir with fresh brake fluid.
(4) Press cylinder pistons inward with wood dowel.
Then release pistons and allow them to return under
spring pressure. Continue bleeding operations until
air bubbles are no longer visible in fluid.
Fig. 10 Master Cylinder Bleeding
1 – BLEEDING TUBES
2 – RESERVOIR
BASE BRAKE BLEEDING
Use Mopar brake fluid, or an equivalent quality
fluid meeting SAE J1703-F and DOT 3 standards
only. Use fresh, clean fluid from a sealed container at
all times.
Do not pump the brake pedal at any time while
bleeding. Air in the system will be compressed into
small bubbles that are distributed throughout the
hydraulic system. This will make additional bleeding
operations necessary.
Do not allow the master cylinder to run out of fluid
during bleed operations. An empty cylinder will allow
additional air to be drawn into the system. Check the
cylinder fluid level frequently and add fluid as
needed.
Bleed only one brake component at a time in the
following sequence:
• Master Cylinder
• Combination Valve
• Rear Antilock Valve
• Right Rear Wheel
• Left Rear Wheel
• Right Front Wheel
• Left Front Wheel
MANUAL BLEEDING
(1) Remove reservoir filler caps and fill reservoir.
(2) If calipers, or wheel cylinders were overhauled,
open all caliper and wheel cylinder bleed screws.
Then close each bleed screw as fluid starts to drip
from it. Top off master cylinder reservoir once more
before proceeding.
BRAKES 5 - 11