2000 DODGE NEON pressure

If the vacuum supply is 12 inches Hg (40.5 kPa) or
more, the power brake booster is defective and must
be replaced. If the vacuum supply is below 12 inches,
continue on with this BASIC TEST.
(6) Shut off the engine.
(7) Connect the vacuum gauge to the vacuum ref-
erence port on the engine intake manifold.
(8)
Start the engine and observe the vacuum gauge.
If the vacuum is still low, check the engine tune
and repair as necessary. If the vacuum is above 12
inches, the hose or check to the booster has a restric-
tion or leak.
Once an adequate vacuum supply is obtained,
repeat the BASIC TEST.
VACUUM LEAK TEST
(1) Disconnect the vacuum hose on the side of the
power brake booster vacuum check valve that leads
to the speed control, then connect a vacuum gauge to
the open vacuum port on the valve.
(2) Remove the remaining hose on the vacuum
check valve that is not the vacuum supply hose com-
ing from the intake manifold. Cap off the open port
on the check valve.
(3) Start the engine.
(4) Allow the engine to warm up to normal operat-
ing temperature and engine idle.
(5) Using vacuum line pliers, close off the vacuum
supply hose near the booster and observe the vacuum
gauge.
If the vacuum drop exceeds 1.0 inch Hg (3.3 kPa)
in one minute, repeat the above steps to confirm the
reading. The vacuum loss should be less than 1.0
inch Hg in one minute time span. If the loss is more
than 1.0 inch Hg, replace the power brake booster. If
it is not, continue on with this test.
(6) Remove the pliers from the hose temporarily.
(7) Apply light effort (approximately 15 lbs. of
force) to the brake pedal and hold the pedal steady.
Do not move the pedal once the pressure is applied
or the test results may vary.
(8) Have an assistant reattach the pliers to the
vacuum supply hose.
(9) Allow 5 seconds for stabilization, then observe
the vacuum gauge.
If the vacuum drop exceeds 3.0 inches Hg (10 kPa)
in 15 seconds, repeat the above steps to confirm the
reading. The vacuum loss should be less than 3.0
inches Hg in 15 seconds time span. If the loss is
more than 3.0 inches Hg, replace the power brake
booster. If it is not, the booster is not defective.
DRUM BRAKE AUTOMATIC ADJUSTER
To properly test the drum brake automatic
adjuster, the aide of a helper inside the vehicle to
apply the brakes will be necessary.(1) Raise the vehicle. Refer to HOISTING in the
LUBRICATION AND MAINTENANCE group for the
proper lifting procedure.
(2) Remove the access plug from the rear adjust-
ment slot in each brake support plate.
(3) Insert a thin screwdriver in the adjustment
slot and push back the adjustment lever. With the
lever in this position, back the star wheel adjustment
off approximately 10 notches. This will eliminate the
possibility that the brake is at full adjustment, and
can be adjusted no further.
(4)
Remove the screwdriver from the adjustment slot.
(5) Watch the star wheel through the adjustment
slot, while a helper applies the brake pedal. As the
brake shoes apply, the adjustment lever should move
downward, turning the star wheel. A definite rotation
of the adjuster star wheel can be observed if the
automatic adjuster is working properly.
If the star wheel does not move as indicated, the
brake drum needs to be removed and further inspec-
tion of the rear brakes is necessary.
(6) If the star wheel is operating properly, readjust
the brakes. Refer to ADJUSTMENTS in this section
of this service manual group.
(7) Reinstall the adjustment slot access plug.
(8) Lower the vehicle.
BRAKE ROTOR
Any servicing of the rotor requires extreme care to
maintain the rotor within service tolerances to
ensure proper brake action.
Excessive runout or wobble in a rotor can increase
pedal travel due to piston knock-back. This increases
guide pin sleeve wear due to the tendency of the cal-
iper to follow the rotor wobble.
When diagnosing a brake noise or pulsation, the
machined disc braking surface should be checked and
inspected.
BRAKING SURFACE INSPECTION
Light braking surface scoring and wear is accept-
able. If heavy scoring or warping is evident, the rotor
must be refaced or replaced. Refer to SERVICE PRO-
CEDURES in this section of this group for informa-
tion on brake rotor machining.
Excessive wear and scoring of the rotor can cause
improper lining contact on the rotor's braking sur-
face. If the ridges on the rotor are not removed before
new brake shoes are installed, improper wear of the
shoes will result.
If a vehicle has not been driven for a period of
time, the rotor's braking surface will rust in the
areas not covered by the brake shoes at that time.
Once the vehicle is driven, noise and chatter from
the disc brakes can result when the brakes are
applied.
5 - 12 BRAKESPL
DIAGNOSIS AND TESTING (Continued)

The in-line proportioning valves used on this vehi-
cle require special pressure fittings to test the pro-
portioning valves for proper proportioning valve
function. The pressure fittings are installed before
and after the proportioning valve being tested to ver-
ify proportioning valve is maintaining the required
hydraulic pressure to the rear wheel brake which it
controls.
The testing of proportioning valves for this vehicle,
if equipped with ABS, can be found in the
ANTILOCK BRAKE SYSTEM section.
PROPORTIONING VALVE TEST
The test procedure is the same for either rear pro-
portioning valve. After road testing the vehicle to
determine which wheel skids first, follow the proce-
dure below for testing the suspect proportioning
valve.
(1) Using a brake pedal holding tool as shown (Fig.
22), depress the brake pedal past its first one inch of
travel and hold it in this position. This will isolate
the master cylinder from the brake hydraulic system
and will not allow the brake fluid to drain out of the
master cylinder reservoir.
(2) Use the figure shown to determine which pro-
portioning valve needs to be tested (Fig. 21).
(3) Remove the hydraulic brake tube from the pro-
portioning valve controlling the rear wheel of the
vehicle that has premature wheel skid.
(4) Remove the proportioning valve from its outlet
port on the master cylinder.CAUTION: Be sure the pressure test fittings being
installed into master cylinder and proportioning
valve, have the correct thread sizes needed.
(5) Install the Brake Pressure Adapters, Special
Tool 8644 and 6805-3 onto the proportioning valve
(Fig. 23).
(6) Install the proportioning valve (with tools) back
into the outlet port on the master cylinder.
(7) Attach a Pressure Gauge, Special Tool
C-4007-A, to each pressure adapter (Fig. 24).
(8) Remove the brake pedal holding tool. Bleed any
air out of the pressure gauge hoses at the pressure
gauge.
(9) With the aid of a helper, apply pressure to the
brake pedal until the reading on proportioning valve
inlet gauge is at the target inlet pressure shown in
the BRAKE PROPORTIONING VALVE APPLICA-
TIONS AND PRESSURE SPECIFICATIONS table
Fig. 22 Brake Pedal Holding Tool
1 ± CLUTCH PEDAL (IF EQUIPPED WITH MANUAL TRANSAXLE)
2 ± THROTTLE PEDAL
3 ± BRAKE PEDAL HOLDING TOOL
4 ± STEERING WHEEL
5 ± DRIVER'S SEAT
6 ± BRAKE PEDAL
Fig. 23 Tools On Valve
1 ± PROPORTIONING VALVE
Fig. 24 Pressure Gauge Set
1 ± SPECIAL TOOL C-4007±A
5 - 16 BRAKESPL
DIAGNOSIS AND TESTING (Continued)

following this procedure. If the inlet gauge pressure
overshoots its target pressure when the pedal is
depressed, release the brake pedal, relieving the
pressure in the system, before reapplying the pedal
to reach the target pressure at the inlet gauge. This
is necessary to get an accurate reading of the outlet
pressure.
(10) Once inlet pressure has been achieved, check
the pressure reading on the proportioning valve out-
let gauge. If the proportioning valve outlet pressure
does not agree with value shown in the table, replace
the proportioning valve. If proportioning valve is
within pressure specifications, the valve is good and
does not require replacement.(11)Reinstall the brake holding tool on the brake
pedal and remove the test equipment from the vehicle.
(12) Remove the tools from the proportioning
valve.
(13) Install the proportioning valve in the master
cylinder and hand tighten until the proportioning
valve is fully installed and its O-ring seal is seated
into the master cylinder. Torque the proportioning
valve to 40 N´m (30 ft. lbs.).
(14) Install the brake tube on the proportioning
valve. Torque the tube nut to 17 N´m (145 in. lbs.).
(15) Bleed the affected brake line. See BASE
BRAKE BLEEDING in this section of this service
manual group.
BRAKE PROPORTIONING VALVE APPLICATIONS AND PRESSURE SPECIFICATIONS
Sales
CodeBrake System Type Split Point Slope IdentificationInlet
PressureOutlet Pressure
BRA 14º Disc/Drum 300 psi 0.34 Black Band 1000 psi 550-650 psi
BRD 14º Disc/Disc 400 psi 0.43 Bar Code Band 1000 psi 600-700 psi
BRAKE FLUID CONTAMINATION
Indications of fluid contamination are swollen or
deteriorated rubber parts. Swelling indicates 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 the fluid sep-
arates into layers, there is mineral oil or other fluid
contamination of the brake fluid.
If the brake fluid is contaminated, drain and thor-
oughly flush the brake system. Replace all the rubber
parts or components containing rubber coming into
contact with the brake fluid including: the master
cylinder; proportioning valves; caliper seals; wheel
cylinder seals; ABS hydraulic control unit; and all
hydraulic fluid hoses.
SERVICE PROCEDURES
BRAKE FLUID LEVEL CHECKING
Brake fluid level should be checked a minimum of
twice a year.
Master cylinder reservoirs are marked, FULL and
MIN, indicating the allowable brake fluid level range
in the master cylinder brake fluid reservoir (Fig. 25).
CAUTION: Use only MoparTbrake fluid or an equiv-
alent from a tightly sealed container. Brake fluid
must conform to DOT 3 specifications. Do not use
petroleum-based fluid because seal damage in the
brake system will result.Although there is a range, the preferred level is
FULL. If necessary, adjust the brake fluid level to
the FULL mark on the side of the master cylinder
brake fluid reservoir.
BASE BRAKE BLEEDING
NOTE: For bleeding the ABS hydraulic system,
refer to ANTILOCK BRAKE SYSTEM BLEEDING in
the ANTILOCK BRAKE SYSTEM section of this ser-
vice manual group.
Fig. 25 Master Cylinder
1 ± POWER BRAKE BOOSTER PARTS IDENTIFICATION TAG
2 ± POWER BRAKE BOOSTER
3 ± BRAKE FLUID PRESSURE SWITCH
4 ± MASTER CYLINDER
PLBRAKES 5 - 17
DIAGNOSIS AND TESTING (Continued)

CAUTION: Before removing the master cylinder
cap, wipe it clean to prevent dirt and other foreign
matter from dropping into the master cylinder res-
ervoir.
CAUTION: Use only MoparTbrake fluid or an equiv-
alent from a fresh, tightly sealed container. Brake
fluid must conform to DOT 3 specifications.
Do not pump the brake pedal at any time while
having a bleeder screw open during the bleeding pro-
cess. This will only increase the amount of air in the
system and make additional bleeding necessary.
Do not allow the master cylinder reservoir to run
out of brake fluid while bleeding the system. An
empty reservoir will allow additional air into the
brake system. Check the fluid level frequently and
add fluid as needed.
The following wheel circuit sequence for bleeding
the brake hydraulic system should be used to ensure
adequate removal of all trapped air from the hydrau-
lic system.
²Left rear wheel
²Right front wheel
²Right rear wheel
²Left front wheel
MANUAL BLEEDING
NOTE: To bleed the brakes manually, the aid of a
helper will be required.
(1) Attach a clear plastic hose to the bleeder screw
and feed the hose into a clear jar containing enough
fresh brake fluid to submerge the end of the hose
(Fig. 26).
(2) Have a helper pump the brake pedal three or
four times and hold it in the down position.
(3) With the pedal in the down position, open the
bleeder screw at least 1 full turn.
(4) Once the brake pedal has dropped, close the
bleeder screw. After the bleeder screw is closed,
release the brake pedal.
(5) Repeat the above steps until all trapped air is
removed from that wheel circuit (usually four or five
times).
(6) Bleed the remaining wheel circuits in the same
manner until all air is removed from the brake sys-
tem. Monitor the fluid level in the master cylinder
reservoir to make sure it does not go dry.
(7) Check the brake pedal travel. If pedal travel is
excessive or has not been improved, some air may
still be trapped in the system. Rebleed the brakes as
necessary.
(8) Test drive the vehicle to verify the brakes are
operating properly and pedal feel is correct.
PRESSURE BLEEDING
NOTE: Follow pressure bleeder manufacturer's
instructions for use of pressure bleeding equip-
ment.
Following the same wheel circuit sequence as pre-
scribed for manual bleeding.
(1) Attach Adapter, Special Tool 6921, to the mas-
ter cylinder reservoir (Fig. 27).
Fig. 26 Proper Method for Purging Air From Brake
System (Typical)
1 ± CLEAR HOSE
2 ± BRAKE CALIPER
3 ± BLEEDER SCREW
4 ± CLEAN BRAKE FLUID
Fig. 27 Special Tool 6921
1 ± MASTER CYLINDER
5 - 18 BRAKESPL
SERVICE PROCEDURES (Continued)

(2) Attach Bleeder Tank, Special Tool C-3496-B, or
an equivalent, to the adapter on the master cylinder.
(3) Attach a clear plastic hose to the bleeder screw
and feed the hose into a clear jar containing enough
fresh brake fluid to submerge the end of the hose
(Fig. 26).
(4) Open the bleeder screw at least one full turn or
more to obtain a steady stream of brake fluid.
(5) After approximately 4±8 ounces of fluid have
been bled through the brake circuit and an air-free
flow is maintained in the clear plastic hose and jar,
close the bleeder screw.
(6) Repeat this procedure at all the remaining
bleeder screws.
(7) Check the brake pedal travel. If pedal travel is
excessive or has not been improved, some air may
still be trapped in the system. Rebleed the brakes as
necessary.
(8) Test drive the vehicle to verify the brakes are
operating properly and pedal feel is correct.
MASTER CYLINDER BLEEDING
(1) Clamp the master cylinder in a vise.
(2) Attach four Master Cylinder Bleed Tubes, Spe-
cial Tool 8358-1, to the four ports of the master cyl-
inder and tighten each in place (Fig. 28). The bleed
tubes for the ports pertaining to the rear brakes are
made to attach to the proportioning valves screwed
into the master cylinder. Position the other end of
the tubes into the master cylinder reservoir so their
outlets are below the surface of the brake fluid in the
reservoir when filled.
(3) Fill the brake fluid reservoir with Mopart
brake fluid, or an equivalent conforming to DOT 3
specifications.
(4) Using a wooden dowel as a pushrod (Fig. 28),
press the pistons inward slowly applying brake pres-
sure, then release the pressure, allowing the pistons
to return to the released position. Repeat this several
times until all air bubbles are expelled out of the
tubes and master cylinder bore.
(5) Remove the bleed tubes from the master cylin-
der and plug the outlet ports.
(6) Install the fill cap on the reservoir.
(7) Remove the master cylinder from the vise.
NOTE: It is not necessary to bleed the entire
hydraulic system after replacing just the master cyl-
inder unless the brake system has been open to air
for an excessive amount of time or air is present in
the lines. Only the master cylinder must be bled
and filled.
BRAKE TUBE REPAIR
Use only double wall 4.75 mm (3/16 in.) steel tub-
ing with Nygal coating for hydraulic brake tube
replacement. Nygal is nylon coated galvanized steel
tubing.
Care must be taken when repairing brake tubing
to avoid kinking the tube. Use the proper bending
and flaring tools. Do not route the tubes against
sharp edges, moving components, or into hot areas.
All tubes should be attached with the recommended
retaining clips.
PREPARING THE BRAKE TUBE FOR FLARING
(1) Use Tubing Cutter, Special Tool C-3478-A, or
an equivalent to cut off the damaged flare or tubing
(Fig. 29).
(2) Make the ends of the tubing to be repaired
square (Fig. 30) to ensure better seating of the flared
end tubing.
(3) Ream out any burrs or rough edges showing on
the inside of the tubing to be flared (Fig. 30).
(4) Strip back enough of the nylon coating at the
end of the length of tubing that will flared so it will
not be in the flare itself. At least 5 mm should be
removed.
NOTE: Place a tube nut on the tubing before flaring
it. It cannot be done after the tube is flared.
Fig. 28 Bleeding Master Cylinder
1 ± WOODEN DOWEL
2 ± MASTER CYLINDER
PLBRAKES 5 - 19
SERVICE PROCEDURES (Continued)

DOUBLE INVERTED TUBING FLARES
After preparing the tubing using the procedure in
PREPARING THE BRAKE TUBE FOR FLARING,
make a double inverted tubing flare using the follow-
ing procedure (Fig. 31).
CAUTION: When using brake tubing with Nygal
coating, always use flare nuts designed for this
coating. They have a larger hole in the center to
accommodate the coating on the tube.
(1) Install the replacement flare nut on the tube so
the threads are facing the flare yet to be made (Fig.
32).
(2) Open the Flaring Tool, Special Tool C-4047 (or
an equivalent), separating the tools vertical posts.
(3) Place the tubing in the jawed hole between the
two vertical posts.
(4) Slowly bring the vertical posts together captur-
ing the tube between the halves. Leave enough tub-
ing sticking through the top of the vertical posts to
allow for flaring. Apply only enough pressure to hold
the tube in place.
Fig. 29 Cutting And Flaring Of Brake Fluid Tubing
Fig. 30 Brake Fluid Tube Preparation For Flaring
1 ± BE SURE ALL BURRS ARE REMOVED FROM INSIDE OF
TUBING
2 ± BE SURE END OF TUBING IS SQUARE BEFORE FLARING
TUBE
3 ± HYDRAULIC BRAKE LINE TUBING
Fig. 31 Double Inverted Brake Line Tubing Flare
1 ± DOUBLE INVERTED-STYLE FLARE
Fig. 32 Double Wall Inverted Flare Connection
1 ± INVERTED FLARE TUBE NUT
2 ± SEAT
3 ± INVERTED DOUBLE FLARE
4 ± TUBE
5 - 20 BRAKESPL
SERVICE PROCEDURES (Continued)

(4) Gently pull back on the brake pedal until the
pedal stops moving. This will ratchet the switch
plunger backward to the correct adjustment position.
(5) Check the stop lamps to verify they are operat-
ing properly and not staying on when the pedal is in
the released position.
MASTER CYLINDER
NOTE: Before proceeding with this procedure,
review SERVICE WARNINGS AND CAUTIONS at the
beginning of REMOVAL AND INSTALLATION in this
section.
REMOVAL
CAUTION: The vacuum in the power brake booster
must be pumped down before removing the master
cylinder to prevent the booster from sucking in any
contamination. This can be done by pumping the
brake pedal while the engine is not running until a
firm brake pedal is achieved.
(1) With the engine not running, pump the brake
pedal 4-5 strokes until the pedal feel is firm.
(2) Disconnect the negative (ground) cable from
the battery and isolate the cable.
(3) Disconnect the positive cable from the battery,
then remove the battery from the battery tray. There
is one nut securing the clamp on the backside of the
battery holding it in place.
(4) Remove the vehicle wiring harness connector
from brake fluid level switch in master cylinder
brake fluid reservoir (Fig. 44).(5) Disconnect the two brake tubes from the mas-
ter cylinder, and two brake tubes from the propor-
tioning valves (Fig. 45). Install plugs at all of the
open brake tube outlets on the master cylinder.
(6) Clean the area around where the master cylin-
der attaches to the power brake booster using a suit-
able brake cleaner such as MopartBrake Parts
Cleaner or an equivalent.
(7) Remove the two nuts attaching the master cyl-
inder to the power brake booster.
(8) Slide the master cylinder straight out of the
power brake booster.
(9) To remove the proportioning valves, unthread
each from the master cylinder.
INSTALLATION
NOTE: The master cylinder must be bled before
installing it on the vehicle.
(1) If removed, install the proportioning valves in
their master cylinder ports. The valves are identical,
so they can be installed in either master cylinder
port going to the rear brakes. Make sure the O-rings
on the proportioning valves are new.
(2) Bleed the master cylinder before installing it
on the vehicle. Refer to MASTER CYLINDER
BLEEDING in SERVICE PROCEDURES within this
section of this service manual group.
(3) Wipe the face of the power brake booster clean
where the master cylinder seal comes in contact
when it's installed. Do not get any cleaner or debris
inside the booster.
Fig. 44 Master Cylinder
1 ± POWER BRAKE BOOSTER PARTS IDENTIFICATION TAG
2 ± POWER BRAKE BOOSTER
3 ± BRAKE FLUID PRESSURE SWITCH
4 ± MASTER CYLINDER
Fig. 45 Brake Tubes At Master Cylinder
1 ± RIGHT FRONT BRAKE TUBE
2 ± LEFT FRONT BRAKE TUBE
3 ± LEFT REAR BRAKE TUBE
4 ± REAR PROPORTIONING VALVES
5 ± RIGHT REAR BRAKE TUBE
5 - 28 BRAKESPL
REMOVAL AND INSTALLATION (Continued)

CALIPER PISTON AND SEALS
CALIPER PISTON REMOVAL
WARNING: UNDER NO CONDITION SHOULD HIGH
PRESSURE AIR EVER BE USED TO REMOVE A PIS-
TON FROM A CALIPER BORE. PERSONAL INJURY
COULD RESULT FROM SUCH A PRACTICE.
NOTE: The safest way to remove the piston from
the caliper bore is to use the hydraulic pressure of
the vehicle's brake system.
(1) Following the removal procedure in DISC
BRAKE SHOES found in this section, remove the
caliper from the brake rotor and hang the assembly
on a wire hook away from rotor and body of the vehi-
cle so brake fluid cannot get on these components.
Remove the brake shoes, and place a small piece of
wood between the piston and caliper fingers.
(2) Carefully depress the brake pedal to hydrauli-
cally push piston out of its bore. Once completed,
apply and hold down the brake pedal to any position
beyond the first inch of pedal travel using a brake
pedal holding tool. This will prevent the fluid in the
master cylinder reservoir from completely draining
out.(3) Disconnect the brake fluid flex hose from the
caliper assembly and remove it from the vehicle.
CALIPER SEAL REMOVAL
CAUTION: Do not use excessive force when clamp-
ing caliper in vise. Excessive vise pressure will
cause bore distortion.
(1) To disassemble the caliper, mount it in a vise
equipped with protective jaws.
(2) Remove the piston dust boot from the caliper
and discard (Fig. 118).
NOTE: Do not use a screw driver or other metal
tool for seal removal. Using such tools can scratch
the bore or leave burrs on the seal groove edges.
(3) Using a soft tool such as a plastic trim stick,
work the piston seal out of its groove in caliper pis-
ton bore (Fig. 119). Discard the old seal.
(4) Clean the piston bore and drilled passage ways
using alcohol or a suitable solvent. Wipe it dry using
only a lint-free cloth.
(5) Inspect the piston bore for scoring or pitting.
Bores that show light scratches or corrosion can usu-
ally be cleared of the light scratches or corrosion
using crocus cloth. Bores that have deep scratches or
scoring should be honed. Use Caliper Hone, Special
Tool C-4095, or the equivalent to hone the bore. Do
Fig. 117 Correctly Installed Guide Pin Sleeve And
Bushing
1 ± CALIPER
2 ± BUSHING
3 ± SLEEVE
Fig. 118 Removing Caliper/Piston Dust Boot
1 ± CALIPER
2 ± SCREWDRIVER
3 ± BOOT
PLBRAKES 5 - 57
DISASSEMBLY AND ASSEMBLY (Continued)