Disc: Other Jaguar X-type I

BRAKE SYSTEM

The braking system is a diagonally split, dual circuit design featuring front and rear disc brakes. The hydraulic system provides separate circuits for each pair of diagonally opposed wheels (left front, right rear and right front, left rear). The front and rear calipers are a single piston floating caliper design. The pads, both front and rear, are asbestos free. The parking brake control is located between the front seats and operates the rear brakes through a cable system. The cable has a manual adjust mechanism incorporated into the parking brake control. See PARKING BRAKE under ADJUSTMENTS. The master cylinder is a tandem design and is mounted to a brake booster to reduce the brake pedal effort. The tandem design will make sure that in the event of one brake circuit failure, the other circuit will remain fully operational. The booster operating rod is connected directly to the brake pedal.

The front disc brake system consists of brake pads, single piston floating disc brake calipers, brake discs, brake caliper anchor plates and brake hoses. (Scheme 64) The brake caliper has 2 retaining bolts that attach it to the brake caliper anchor plate. The brake caliper anchor plate is attached to the wheel knuckle with 2 retaining bolts. The hydraulic system provides separate circuits for each pair of diagonally opposed wheels (i.e. left front, right rear and right front, left rear). The brake disc is manufactured from cast iron, is of the vented type and is retained on the wheel hub studs by the wheel and wheel nuts. The front brake calipers are mounted on the wheel knuckles. Front brake calipers are a single, sliding piston type that ensures equal effort is applied through both brake pads.

Scheme 64

The rear disc brake system consists of brake pads, single piston floating disc brake calipers, brake discs, brake caliper anchor plates, brake hoses, and parking brake cables. (Scheme 65) The caliper has 2 retaining bolts that attach the caliper to the anchor plate. The anchor plate is attached to the hub carrier with 2 bolts. The hydraulic system provides separate circuits for each pair of diagonally opposed wheels (i.e. left front, right rear and right front, left rear). The brake disc is manufactured from cast iron, is of the solid type and is retained on the hub by the wheel and the wheel studs. The rear brake calipers are mounted on the hub carrier. Rear brake calipers are a single, sliding piston type that ensures equal effort is applied through both brake pads. The rear brake caliper incorporates the parking brake which is self adjusting according to brake pad wear.

Scheme 65

PARKING BRAKE

The parking brake control system is cable operated and controlled by an independent, hand operated parking brake control lever. (Scheme 66) The parking brake control lever activates the rear brake calipers through a cable and rear caliper lever with a ball-in-ramp mechanism. The rear calipers self adjusts to compensate for pad wear through hydraulic operation. The parking brake cables are either self-adjusting or manually adjusted. For parking brake cable adjustments, see PARKING BRAKE under ADJUSTMENTS.

Scheme 66

BLEEDING BRAKE SYSTEM

Note. Ensure the brake fluid level does not fall below the fluid reservoir MIN (minimum) mark when bleeding the brake system.

Note. The system consists of separate circuits for each front and diagonally opposite rear wheel. Each front to rear circuit and each wheel circuit can be bled individually of each other. The ABS hydraulic control service unit is supplied pre-filled with brake fluid. Therefore, a conventional bleed procedure should be adequate to remove all the air from the brake system.

BLEEDING PROCEDURE

1. Raise and support vehicle. Open engine compartment hood and fit paint protection covers to fenders.
2. Remove the master cylinder reservoir filler cap. Fill fluid reservoir to the MAX (maximum) mark.
3. Install a bleed tube to the right rear brake caliper bleed nipple.
4. Bleed the circuit by: Making sure the bleed tube is firmly attached to the bleed nipple. Submerging the end of the bleed tube in a bleed jar containing a small quantity of approved brake fluid. Positioning the bleed jar base at least 11.8" (300 mm) above the bleed nipple to maintain fluid pressure and prevent air leaking past the bleed nipple threads. Open the bleed nipple one half turn. Slowly apply the brake pedal to its maximum travel (this will force brake fluid into the bleed jar). Close the bleed nipple. Return the brake pedal to rest position. Wait 2 seconds to allow the brake fluid to replenish the system. Fill up the master cylinder reservoir to the MAX mark as necessary. Continue to bleed the circuit until air free brake fluid is pumped into the jar. Fully tighten the bleed nipple.
5. Ensuring that fluid level in master cylinder reservoir does not fall below the MIN mark, repeat procedure for each brake caliper in proper sequence. See «BRAKE BLEEDING SEQUENCE»(ref-163547-S39264163742004070200000) table. Fully tighten the bleed nipples.
6. Ensure that brake fluid level is at the MAX mark on reservoir and fit cap. Start the engine and check for correct brake pedal travel and pressure. Apply the brakes and check the system for leaks. Top off brake fluid as necessary, bringing fluid level to the MAX mark.

BRAKE BLEEDING SEQUENCE (1)

Scheme 67

Note. Parking brake may be equipped with a self-adjusting parking brake cable or a manually adjusted parking brake cable. To determine if the parking brake cable is self-adjusting or manually adjusted, the manually adjusted cable will have a parking brake cable adjuster that is visible from underneath the vehicle. (Scheme 69)

Vehicles With Self-Adjusting Parking Brake

The rear calipers self adjusts to compensate for pad wear through hydraulic operation. To adjust the cable, operate the parking brake control lever several times.

Vehicles With Manually Adjusted Parking Brake

Note. Special tool required: Parking Brake Cable Adjuster Socket (206-087). see scheme 66

1. Release the parking brake. Raise and support vehicle.
2. Using suitable feeler gauges, measure the gap between the parking brake lever and the parking brake lever stop. (Scheme 68) If the parking brake lever gap measurement is: Between.004" (0.1 mm) to a maximum of.039" (1 mm) no further action is required. Not between.004" (0.1 mm) to a maximum of.039" (1 mm), continue with the adjustment procedure.
3. Using Parking Brake Cable Adjuster Socket (206-087), adjust the parking brake cable to obtain the required measurement. (Scheme 69)
4. Lower the vehicle. Operate the parking brake lever to maximum travel 5 times to allow the parking brake cables to stretch.
5. Raise and support vehicle.
6. Using suitable feeler gauges, measure the gap between the parking brake lever and the parking brake lever stop. (Scheme 68) If the parking brake lever gap measurement is: Between.004" (0.1 mm) to a maximum of.039" (1 mm) no further action is required. Not between 0.004" (0.1 mm) to a maximum of 0.039" (1 mm), repeat the adjustment procedure.

Scheme 68

Scheme 69

Possible Causes

1. Fluid level low. Fill system to specification and check for leaks.
2. Brake fluid level sensor failure. Install a NEW brake fluid reservoir. See «BRAKE FLUID RESERVOIR»(ref-163547-S13926928992004070700000) under REMOVAL & INSTALLATION.
3. Parking brake control out of adjustment. See «PARKING BRAKE»(ref-163547-S23898690452004070200000) under ADJUSTMENTS.
4. Electrical circuit failure. For 2002 models, see «INSTRUMENT CLUSTER»(ref-151246-S00916435412002121200000) in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. For 2003 models, see «INSTRUMENT CLUSTER»(ref-159326-S15832097972003112600000) in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. For 2004 models, see INSTRUMENT CLUSTER in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. For 2005 models, see INSTRUMENT CLUSTER in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.

BRAKE BOOSTER

Note. Road test vehicle for proper operation after completion of any repairs. See ROAD TEST .

1. Check all hoses and connections. All unused vacuum connectors should be capped. Hoses and their connections should be correctly secured and in good condition with no holes and no collapsed areas. Inspect the valve on the brake booster for damage.
2. Check the hydraulic brake system for leaks or low fluid.
3. With the transmission in PARK (automatic transmissions) or NEUTRAL (manual transmissions) position, stop the engine and apply the parking brake. Pump the brake pedal several times to exhaust all vacuum in the system.
4. With the engine switched off and all vacuum in the system exhausted, apply the brake pedal and hold it down. Start the engine. If the vacuum system is operating, the brake pedal will tend to move downward under constant foot pressure. If no motion is felt, the vacuum booster system is not functioning.
5. Remove the vacuum hose from the brake booster. Manifold vacuum should be available at the brake booster end of the hose with the engine at idle speed and the transmission in PARK or NEUTRAL. Make sure that all unused vacuum outlets are correctly capped, hose connectors are correctly secured and vacuum hoses are in good condition. When it is established that manifold vacuum is available to the brake booster, connect the vacuum hose to the brake booster and repeat step 3 . If no downward movement of the brake pedal is felt, install a NEW brake booster. See «BRAKE BOOSTER»(ref-163547-S29690510722004070700000) under REMOVAL & INSTALLATION.
6. Operate the engine for a minimum of 10 seconds at a fast idle. Stop the engine and allow the vehicle to stand for 10 minutes. Then, apply the brake pedal with approximately 20 Lbs. (89 N) of force. The pedal feel on application should be the same as that noted with the engine running. If the brake pedal feels hard (no power assist), install a NEW valve and then repeat the test. If the brake pedal still feels hard, install a NEW brake booster. See «BRAKE BOOSTER»(ref-163547-S29690510722004070700000) under REMOVAL & INSTALLATION. If the brake pedal movement feels spongy, bleed the brake system. See «BLEEDING BRAKE SYSTEM»(ref-163547-S36542288862004070200000) .

BRAKE MASTER CYLINDER

Note. Road test vehicle for proper operation after completion of any repairs. See ROAD TEST .

Usually, the first and strongest indicator of anything wrong in the brake system is a feeling through the brake pedal. In diagnosing the condition of the brake master cylinder, check pedal feel as evidence of a brake concern. Check for brake warning lamp illumination and the brake fluid level in the brake master cylinder reservoir.

Normal Conditions

The following conditions are considered normal and are not indications that the brake master cylinder is in need of repair.

1. New brake systems are designed to produce a pedal effort that is not as hard as in the past. Complaints of light pedal efforts should be compared to the pedal efforts of another vehicle of the same model and year.
2. The fluid level will fall with brake pad wear.

Abnormal Conditions

Note. Prior to carrying out any diagnosis, make sure the brake system warning indicator is functional.

Changes in the brake pedal feel or brake pedal travel are indicators that something could be wrong in the brake system. The diagnostic procedure and techniques use brake pedal feel, warning indicator illumination and low brake fluid level as indicators to diagnosing brake system concerns. The following conditions are considered abnormal and indicate that the brake master cylinder is in need of repair

1. Brake Pedal Goes Down Fast - This could be caused by an external or internal leak.
2. Brake Pedal Goes Down Slowly - This could be caused by an internal or external leak.
3. Brake Pedal Is Low Or Feels Spongy - This condition may be caused by no fluid in the brake master cylinder, reservoir cap vent holes clogged or air in the hydraulic system.
4. Brake Pedal Effort Is Excessive - This may be caused by a bind or obstruction in the pedal/linkage, a faulty non return valve, booster or insufficient booster vacuum.
5. Rear Brakes Lock Up During Light Pedal Force - This may be caused by damaged brake pads, an incorrectly adjusted parking brake, a partially applied parking brake, a damaged ABS sensor or bearing failure.
6. Brake Pedal Effort Erratic - This condition could be caused by the brake booster or incorrectly installed brake pads.
7. Brake Warning Indicator Is On - This may be caused by low fluid level or float assembly damaged.

Non-Pressure Leaks

Any reduced fluid volume in the brake master cylinder reservoir condition may be caused by non-pressure external leaks.

1. TYPE 1 An external leak may occur at the master cylinder reservoir cap because of incorrect positioning of gasket and cap. Reposition cap and gasket.
2. TYPE 2 An external leak may occur at the reservoir mounting seals. Repair such a leak by installing NEW seals and make sure that the reservoir retaining pin is correctly installed. See «BRAKE FLUID RESERVOIR»(ref-163547-S13926928992004070700000) under REMOVAL & INSTALLATION.
3. TYPE 3 An external leak may occur in the manual transmission clutch operating system. See appropriate MANUAL TRANSMISSION article in TRANSAXLE/TRANSMISSION.