Dodge Nitro. Manual — part 352

2007 BRAKES

Base - Service Information - Nitro

BASE - SERVICE INFORMATION

DESCRIPTION

BRAKE SYSTEM

ESP and Power assist four wheel disc brakes are standard equipment. Front disc brake components consist of
single piston calipers and ventilated rotors. Rear disc brakes use a drum in hat design for the parking brake
which is activated by brake shoes pressing against the inside of the drum in hat rotor.

The parking brake mechanism is lever and cable operated. The cables are attached on a equalizer on the lever
cable. The parking brakes are operated by a hand lever.

The vehicle is equipped with ESP (Electronic Stability Program). There are four wheel speed sensors, one
sensor at each wheel to monitor input.

A dual diaphragm vacuum power brake booster is used for all applications. All models have an aluminum
master cylinder with plastic reservoir.

Factory brake lining on all models consists of an organic base material combined with metallic particles. The
original equipment linings do not contain asbestos.

WARNING

WARNING

WARNING:

DaimlerChrysler does not manufacture any vehicles or replacement parts
that contain asbestos. Aftermarket products may or may not contain
asbestos. Refer to aftermarket product packaging for product information.
Whether the product contains asbestos or not, dust and dirt can
accumulate on brake parts during normal use. Follow practices
prescribed by appropriate regulations for the handling, processing and
disposing of dust and debris.

CAUTION: Never use gasoline, kerosene, alcohol, motor oil, transmission fluid, or

any fluid containing mineral oil to clean the system components. These
fluids damage rubber cups and seals. Use only fresh brake fluid or Mopar
brake cleaner to clean or flush brake system components. These are the
only cleaning materials recommended. If system contamination is
suspected, check the fluid for dirt, discoloration, or separation into
distinct layers. Also check the reservoir cap seal for distortion. Drain and
flush the system with new brake fluid if contamination is suspected.

2007 Dodge Nitro R/T

2007 BRAKES Base - Service Information - Nitro

2007 Dodge Nitro R/T

2007 BRAKES Base - Service Information - Nitro

DIAGNOSIS AND TESTING

BASE BRAKE SYSTEM

Base brake components consist of the brake shoes, calipers, rotors, brake lines, master cylinder, booster, and
parking brake components.

Brake diagnosis involves determining if the problem is related to a mechanical, hydraulic, or vacuum operated
component.

The first diagnosis step is the preliminary check.

PRELIMINARY BRAKE CHECK

1. Check condition of tires and wheels. Damaged wheels and worn, damaged, or underinflated tires can

cause pull, shudder, vibration, and a condition similar to grab.

2. If complaint was based on noise when braking, check suspension components. Jounce front and rear of

vehicle and listen for noise that might be caused by loose, worn or damaged suspension or steering
components.

3. Inspect brake fluid level and condition. Note that the brake reservoir fluid level will decrease in

proportion to normal lining wear. Also note that brake fluid tends to darken over time. This is normal
and should not be mistaken for contamination.



If fluid level is abnormally low, look for evidence of leaks at calipers, brake lines, and master
cylinder.



If fluid appears contaminated, drain out a sample to examine. System will have to be flushed if
fluid is separated into layers, or contains a substance other than brake fluid. The system seals and
cups will also have to be replaced after flushing. Use clean brake fluid to flush the system.

4. Check parking brake operation. Verify free movement and full release of cables and hand lever. Also note

if vehicle was being operated with parking brake partially applied.

5. Check brake pedal operation. Verify that pedal does not bind and has adequate free play. If pedal lacks

free play, check pedal and power booster for being loose or for bind condition. Do not road test until
condition is corrected.

6. Check booster vacuum check valve and hose.

7. If components checked appear OK, road test the vehicle.

CAUTION: Use Mopar brake fluid, or an equivalent quality fluid meeting SAE/DOT

standards J1703 and DOT 3. Brake fluid must be clean and free of
contaminants. Use fresh fluid from sealed containers only to ensure
proper antilock component operation.

CAUTION: Use Mopar multi-mileage or high temperature grease to lubricate caliper

slide surfaces, drum brake pivot pins, and shoe contact points on the
backing plates. Use multi-mileage grease or GE 661 or Dow 111 silicone
grease on caliper slide pins to ensure proper operation.

2007 Dodge Nitro R/T

2007 BRAKES Base - Service Information - Nitro

ROAD TESTING

1. If complaint involved low brake pedal, pump pedal and note if it comes back up to normal height.

2. Check brake pedal response with transmission in Neutral and engine running. Pedal should remain firm

under constant foot pressure.

3. During road test, make normal and firm brake stops in 40-64 km/h (25-40 mph) range. Note faulty brake

operation such as low pedal, hard pedal, fade, pedal pulsation, pull, grab, drag, noise, etc.

4. Attempt to stop the vehicle with the parking brake only and note grab, drag, noise, etc.

PEDAL FALLS AWAY

A brake pedal that falls away under steady foot pressure is generally the result of a system leak. The leak point
could be at a brake line, fitting, hose, or caliper. If leakage is severe, fluid will be evident at or around the
leaking component.

Internal leakage (seal by-pass) in the master cylinder caused by worn or damaged piston cups, may also be the
problem cause.

An internal leak in the ABS or junction block may also be the problem with no physical evidence.

Pedal fall-away can also be caused by the vacuum level building in the booster. This is common, especially in
vehicles equipped with a vacuum pump, and is not an indication of malfunction. To differentiate between a leak
and vacuum build, turn off the engine, and pump the pedal 4-5 times (until the vacuum is depleted), then press
and hold the pedal with constant force. If the pedal still falls away, pursue root causing leaks. If the pedal
remains firm under this condition, leaks are not the issue.

LOW PEDAL

If a low pedal is experienced, pump the pedal several times. If the pedal comes back up worn linings or rotors
are the most likely causes. The proper course of action is to inspect and replace all worn components.

SPONGY PEDAL

A spongy pedal is most often caused by air in the system. However, substandard brake lines and hoses can also
cause a spongy pedal. The proper course of action is to bleed the system, and replace substandard quality brake
hoses if suspected.

HARD PEDAL OR HIGH PEDAL EFFORT

A hard pedal or high pedal effort may be due to lining that is water soaked, contaminated, glazed, or badly
worn. The power booster or check valve could also be faulty.

Hard pedal is also a symptom of a vacuum leak - check hoses and connections.

PEDAL PULSATION

Pedal pulsation is caused by components that are loose, or beyond tolerance limits.

2007 Dodge Nitro R/T

2007 BRAKES Base - Service Information - Nitro

The primary cause of pulsation are disc brake rotors with excessive lateral runout or thickness variation. Other
causes are loose wheel bearings or calipers and worn, damaged tires.

BRAKE DRAG

Brake drag occurs when the lining is in constant contact with the rotor or drum. Drag can occur at one wheel, all
wheels, fronts only, or rears only.

Drag is a product of incomplete brake shoe release. Drag can be minor or severe enough to overheat the linings,
rotors and drums.

Minor drag will usually cause slight surface charring of the lining. It can also generate hard spots in rotors and
drums from the overheat-cool down process. In most cases, the rotors, drums, wheels and tires are quite warm
to the touch after the vehicle is stopped.

Severe drag can char the brake lining all the way through. It can also distort and score rotors and drums to the
point of replacement. The wheels, tires and brake components will be extremely hot. In severe cases, the lining
may generate smoke as it chars from overheating.

Common causes of brake drag are:

Seized or improperly adjusted parking brake cables.

Loose/worn wheel bearing.

Seized caliper piston.

Caliper binding on corroded bushings or rusted slide surfaces.

Loose caliper mounting.

Drum parking brake shoes binding on worn/damaged support plates.

Mis-assembled components.

Long booster output rod.

If brake drag occurs at all wheels, the problem may be related to a blocked master cylinder return port, or faulty
power booster (binds-does not release).

BRAKE FADE

Brake fade is usually a product of overheating caused by brake drag. However, brake overheating and resulting
fade can also be caused by riding the brake pedal, making repeated high deceleration stops in a short time span,
or constant braking on steep mountain roads. Refer to BRAKE DRAG for causes.

BRAKE PULL

Front brake pull condition could result from:

NOTE:

Some pedal pulsation may be felt during ABS activation.

2007 Dodge Nitro R/T

2007 BRAKES Base - Service Information - Nitro