Volkswagen Jetta, Golf, GTI 1999, 2000 Brake System 47 Brakes - Hydraulic Components (Page GR-47)

Transcription

1 47 Brakes - Hydraulic Components (Page GR-47) FS III front brake calipers, servicing Front brake caliper piston, removing and installing FN 3 front brake calipers, servicing Front caliper piston, removing and installing Rear brake caliper, servicing Pressure leak test Rear brake caliper piston, removing and installing Brake pressure regulator, mounting Brake pressure regulator, checking and adjusting Specifications for load dependent brake pressure regulator Brake system, bleeding Brake system, bleeding using US1116 pressure bleeder Brake system, bleeding without pressure bleeder Brake master cylinder/brake booster, servicing Vacuum pump for brake booster, removing and installing (vehicles with Diesel engines) Brake master cylinder, removing and installing Brake booster, removing and installing

2 FS III front brake calipers, servicing (Page 47-1) Notes: Install all parts supplied in the repair kit. New brake calipers are filled with brake fluid and are pre-bled. Apply a thin coat of lubricant, Part No. G A2 to brake cylinders, pistons and seals. 1 - Dust cap 2 - Bleeder valve Apply thin coat of assembly lubricant G A2 to threads before installing 3 - Cap Install in mounting bushing 4 - Guide pin, 28 Nm (21 ft lb) Removing and installing Page 47-3

3 FS III front brake calipers, servicing (Page 47-2) 5 - Mounting bushing Install in brake caliper housing 6 - Brake caliper housing 7 - Protective seal Removing and installing Page Piston Removing and installing Page 47-3 Before installing apply a thin coat of assembly lubricant, Part No. G A2, to piston 9 - Piston seal Removing and installing Page 47-3

4 FS III front brake calipers, servicing (Page 47-3) Front brake caliper piston, removing and installing Special tools and equipment required 3409 Wedge Piston resetting tool Removing - Force piston out of brake caliper housing using compressed air. Notes: Place a piece of wood in the recess to prevent damaging the piston.

5 FS III front brake calipers, servicing (Page 47-4) - Remove piston seal using wedge Notes: When removing piston seal make sure that the cylinder bore is not damaged. Installing - Lubricate piston, piston seal and cylinder bore lightly with assembly lubricant G A2 - Install new piston seal in caliper. - Place protective seal with outer sealing lip on piston.

6 FS III front brake calipers, servicing (Page 47-5) - Hold piston in front of caliper and insert inner sealing lip into groove in cylinder using wedge Press piston into brake caliper housing using piston resetting tool. The protective seal outer sealing lip must slip into the piston groove.

7 FN 3 front brake calipers, servicing (Page 47-6) Notes: Install all parts supplied in the repair kit. New brake calipers are filled with brake fluid and are pre-bled. Apply a thin coat of lubricant, Part No. G A2 to brake cylinders, pistons and seals. 1 - Dust cap 2 - Bleeder valve Apply thin coat of assembly lubricant G A2 to threads before installing 3 - Cap Insert in mounting bushing

8 FN 3 front brake calipers, servicing (Page 47-7) 4 - Guide pin, 28 Nm (21 ft lb) 5 - Mounting bushing Insert into brake caliper housing 6 - Brake caliper housing 7 - Brake carrier 8 - Retaining spring Insert with both ends in holes in brake caliper housing 9 - Piston seal Removing and installing Page 47-9

9 FN 3 front brake calipers, servicing (Page 47-8) 11 - Piston Removing and installing Page 47-9 Apply thin coat of assembly lubricant G A2 to piston before installing Piston diameter: 54 mm (2.125 in.) 12 - Protective seal Do not damage when inserting piston

10 FN 3 front brake calipers, servicing (Page 47-9) Front caliper piston, removing and installing Special tools and equipment required 3409 Wedge VAG 1331 Torque wrench or equivalent Piston resetting tool

11 FN 3 front brake calipers, servicing (Page 47-10) Removing - Force piston out of brake caliper housing using compressed air. Notes: Place a piece of wood in the recess to prevent damaging the piston. - Remove seal using wedge Notes: When removing the piston seal make sure that the cylinder bore is not damaged.

12 FN 3 front brake calipers, servicing (Page 47-11) Installing - Thinly coat piston and piston seal with assembly lubricant G A2 before inserting. - Place protective seal with outer sealing lip on piston. - Hold piston in front of caliper and insert inner sealing lip into groove in cylinder using sedge 3409.

13 FN 3 front brake calipers, servicing (Page 47-12) - Press piston into brake caliper housing using piston resetting tool. The protective seal outer sealing lip must slip into the piston groove.

14 Rear brake caliper, servicing (Page 47-13) Notes: When repairing install all parts supplied in repair kit. New brake calipers are filled with brake fluid and pre-bled. Apply a thin coat of assembly lubricant, Part No. G A2, to brake cylinders, pistons and seals. When repairing, it is essential to appropriately pre-bleed the brake calipers (without brake pads) before installation in the vehicle Page Self-locking hex bolt, 35 Nm (26 ft lb) Always replace When loosening and tightening counter-hold on guide pin 2 - Bleeder valve Apply a thin coat of assembly lubricant G A2 to threads before installing

15 Rear brake caliper, servicing (Page 47-14) 3 - Dust cap 4 - Guide pins Grease before pulling on protective cap 5 - Protective cap Pull onto brake carrier and guide pin 6 - Brake carrier with guide pin and protective cap Replacement part is assembled with sufficient grease on guide pins If protective caps or guide pins are damaged, install repair kit. Use grease packet supplied to lubricate the guide pins.

16 Rear brake caliper, servicing (Page 47-15) 7 - Protective seal Pull outer sealing lip onto piston 8 - Piston with automatic adjustment Removing and installing Page Apply thin coat of assembly lubricant G A2 to piston before inserting 9 - Sealing ring Removing and installing Page Brake caliper housing with parking brake cable lever If a leak exists at the parking brake cable lever replace brake caliper housing After repairing, pre-bleed caliper housing Page 47-19

17 Rear brake caliper, servicing (Page 47-16) Rear brake caliper piston, removing and installing Special tools and equipment required 3272 Piston resetting and removal tool 3409 Wedge Bleeder bottle

18 Rear brake caliper, servicing (Page 47-17) Removing - Remove piston from brake caliper housing by turning knurled wheel counterclockwise. Notes: Install special tool 3272 with the collar (arrow) positioned before the piston. If the piston is difficult to move, use a 13 mm open end wrench on the flats (arrow - A-) provided for this purpose. - Remove seal using wedge 3409.

19 Rear brake caliper, servicing (Page 47-18) Installing - Apply a thin coat of assembly lubricant G A2 to piston and seal before inserting. - Place protective seal with outer sealing lip on the piston. - Hold piston in front of caliper housing and install inner sealing lip into groove in cylinder using wedge 3409.

20 Rear brake caliper, servicing (Page 47-19) - Screw piston into housing by turning knurled wheel clockwise. Notes: Install special tool 3272 with the collar (arrow) seated on the brake caliper. If the piston is difficult to move, use a 13 mm open end wrench on the flats (arrow - A-) provided for this purpose. If the piston is pushed back with a piston resetting tool or by operating the foot brake, the automatic adjustment in the brake caliper is destroyed. - Install brake pads. Pre-bleeding brake caliper - Position brake caliper as shown in illustration. - Open bleeder valve (arrow -A-) and fill a standard bleeder bottle with brake fluid until bubble-free brake fluid flows from brake hose connection (arrow -B-). - Close bleeder valve.

21 Rear brake caliper, servicing (Page 47-20) Pressure leak test Special tools and equipment required VAG 1310 A Brake pressure gauge Requirements Brake system (hydraulic unit, brake hoses, brake lines and brake calipers) must function properly and not leak. - Remove bleeder valve at one front brake caliper. Connect pressure gauge from VAG 1310 and bleed. - Apply pressure to brake pedal until the gauge indicates a pressure of 50 bar (725 psi). The pressure must not drop by more than 4 bar during the test period of 45 seconds. Renew master cylinder if pressure drops greatly. Pressure must not drop by more than 4 bar (58 psi) during the test period (45 seconds) - If pressure drops more than specified, replace master cylinder.

22 Brake pressure regulator, mounting (Page 47-21) 1 - Brake pressure regulator Checking and adjusting Page Socket head bolt, 21 Nm (15 ft lb) 3 - Bolt 4 - Nut, 21 Nm (15 ft lb) 5 - Spring 6 - Mounting bracket

23 Brake pressure regulator, checking and adjusting (Page 47-22) Special tools and equipment required VAG 1310 Brake pressure gauge The brake pressure regulator is mounted on a bracket and mounted to the rear axle. The regulator is controlled from the rear axle by a spring. Checking function - Depress brake pedal firmly once and release quickly (vehicle standing on its wheels). Brake pressure regulator must move.

24 Brake pressure regulator, checking and adjusting (Page 47-23) Checking and adjusting Requirements Vehicle emptied of all cargo and passengers Driver (approx. 75 kg [165 lb]) in driver's seat Full fuel tank Full windshield washer / headlight washer reservoir Spare tire, tool kit and jack in place Checking - Lift vehicle and connect pressure gauges to left front and right rear brake calipers. - Bleed both gauges. - Lower and bounce rear of vehicle several times. - Depress brake pedal to obtain specified pressure at front axle, then read pressure at rear axle. - Compare reading with specifications Page and if necessary adjust.

25 Brake pressure regulator, checking and adjusting (Page 47-24) Specifications for load dependent brake pressure regulator

26 Brake pressure regulator, checking and adjusting (Page 47-25) Adjusting brake pressure regulator Rear axle test pressure too high: - Release tension on regulator spring. Rear axle test pressures too low: - Increase tension regulator spring. Notes: Do not adjust with brake pedal depressed. Use the following work sequence: - Read pressure. - Release brake pedal. - Adjust spring. - Depress brake pedal again. - Read pressure and if necessary, readjust. - Remove pressure gauges and bleed brake system Page

27 Brake system, bleeding (Page 47-26) Vehicles with ABS and ABS/EDL When at least one chamber in the brake fluid reservoir is completely empty (e.g. leaks in braking system) the hydraulic unit must be bled using the VAG 1551 scan tool in function 04, "basic setting". WARNING! Do not exceed a filling pressure of 1 bar (14.5 psi) when filling with brake fluid using pressure bleeder US1116. The brake system will not be completely bled if excessive pressure is used. Basic setting Notes: Repair Manual, ABS/EDL On Board Diagnostic (OBD), Repair Group 01 Bleeding the brake system on vehicles with ABS is the same as for vehicles with conventional braking systems. Brake fluid absorbs moisture from the air and must therefore be replaced every two years. Use only new, unused and approved brake fluid that complies with MVSS 116 DOT 4. Brake fluid is poisonous. Also due to its corrosive effect brake fluid must not come into contact with paintwork. Brake fluid must always be stored in air tight containers. Do not use silicone-based brake fluid (DOT 5). Even the smallest trace can cause severe corrosion in the brake system. Rinse off brake fluid spillages using plenty of water.

28 Brake system, bleeding (Page 47-27) Brake system, bleeding using US1116 pressure bleeder Special tools and equipment required US 1116 brake bleeder Notes: Bleeding the brake system on vehicles with ABS is the same as for vehicles with a conventional brake system On vehicles with a brake pressure regulator, move the regulator lever when bleeding rear brakes. - Connect brake filling and bleeding unit. - Open bleeder valves in specified sequence and bleed brake calipers. Bleeding sequence 1-Right rear caliper 2-Left rear caliper 3-Right front caliper 4-Left front caliper

29 Vehicles with ABS or ABS/EDL - Test drive vehicle and perform at least one brake application sufficient to engage ABS regulation.

30 Brake system, bleeding (Page 47-28) Brake system, bleeding without pressure bleeder - Build-up brake pressure in brake system by pumping brake pedal. - Connect hose from bleeder bottle to brake bleeder valve at each wheel in turn (Bleeding sequence Page 47-27). - Open bleeder valve. - Hold brake pedal down, close bleed screw. Notes: The brake fluid level in the reservoir must not fall below the MIN mark during bleeding. - Release brake pedal. - Repeat operation until brake fluid flows without air bubbles. Brake fluid, changing Repair Manual, Maintenance

31 Brake master cylinder/brake booster, servicing (Page 47-29) Notes: Master cylinders and brake boosters can be replaced separately. 1 - Brake booster With gasoline engines vacuum is taken from the intake manifold With Diesel engines a vacuum pump provides the required vacuum. Functional check: - With engine switched off, depress brake pedal firmly several times (to exhaust vacuum in booster). - Depress brake pedal with average foot pressure, hold and start engine. If the booster is working properly, the pedal will give slightly under foot (booster becomes effective). If faulty replace complete. Check valve (in vacuum hose), Functional check Page Separating booster from brake pedal Page Removing and installing Page 47-37

32 Brake master cylinder/brake booster, servicing (Page 47-30) 2 - Cap 3 - Brake fluid reservoir 4 - Sealing plug Moisten with brake fluid and press into reservoir 5 - Retainer pin Insert through brake master cylinder 6 - Brake master cylinder Cannot be repaired. If faulty, replace complete. 7 - Self-locking hex nut, 20 Nm (15 ft lb) 8 - Seal Always replace 9 - Sealing plug

33 Brake master cylinder/brake booster, servicing (Page 47-31) 10 - Vacuum hose Insert into brake booster 11 - Gasket 12 - Self-locking nut, 20 Nm (15 ft lb) 13 - Boot Must be seated correctly or may cause air noise

34 Brake master cylinder/brake booster, servicing (Page 47-32) Vacuum pump for brake booster, removing and installing (vehicles with Diesel engines) Removing - Remove retainer for wiring harness from vacuum pump. - Loosen vacuum hose clamp (arrow -A-) and remove hose from pump. - Remove bolts (arrow -B-) on flange. - Remove vacuum pump. Notes: The vacuum pump cannot be repaired.

35 Brake master cylinder/brake booster, servicing (Page 47-33) Installing Notes: When installing the vacuum pump be sure that the follower engages correctly with the camshaft. - Install bolts (arrows -B-) on cylinder head flange. - Secure vacuum hose with clamp (arrow -A-). - Check function of check valve -A-. Air must pass through in direction of arrow Valve must remain closed in opposite direction - Ensure that check valve is installed correctly.

36 Brake master cylinder, removing and installing (Page 47-34) Special tools and equipment required 3094 Hose clamps or equivalent Additional information Repair Manual, ABS/EDL On Board Diagnostic (OBD), Repair Group 01 Repair Manual, Manual Transmission 02J Removing - Obtain radio code on vehicles with coded radio. - Disconnect battery. - Disconnector connector -1- of Mass Air Flow MAF sensor from air filter tube. - Remove bolts -2- at air filter -3- and move filter to left side. - On vehicles with Diesel engines, remove relay panel above brake booster.

37 Brake master cylinder, removing and installing (Page 47-35) - Spread sufficient lint-free cloths in area of plenum, and on engine and transmission to catch any escaping brake fluid. - Using a bleeder bottle, draw off as much brake fluid as possible from brake fluid reservoir. - Clamp clutch master cylinder supply hose with clamp Remove clutch master cylinder supply hose from reservoir. - Disconnect brake fluid level sensor wiring connector. Vehicles with automatic transmission - Disconnect wiring connectors from pressure sensors -a- and -b-. All vehicles - Disconnect brake lines at brake master cylinder and seal with plugs from repair kit, Part No. 1H A. - Remove nuts securing brake master cylinder to brake booster. - Remove heat shield if installed. - Carefully remove brake master cylinder from brake booster. Installing - Install master cylinder in reverse order of removal.

38 Brake master cylinder, removing and installing (Page 47-36) Observe the following points when installing: - When connecting brake master cylinder and brake booster, be sure that push rod is correctly located in brake master cylinder. - After installing, bleed brakes Page and clutch. Repair Manual, Manual Transmission 02J, Repair Group 30 - Restore basic setting. Repair Manual, ABS, ABS/EDL On Board Diagnostic (OBD), Repair Group 01

39 Brake booster, removing and installing (Page 47-37) Special tools and equipment required 3094 Hose clamps or equivalent Additional information Repair Manual, ABS/EDL On Board Diagnostic (OBD), Repair Group 01 Removing - Note or request radio code on vehicles with coded radio if necessary. - Disconnect battery. Vehicles with manual transmission - Clamp clutch master cylinder supply hose with special tool 3094 or equivalent. - Remove clutch master cylinder supply hose from reservoir. All vehicles - Remove ABS control module and hydraulic unit Page Disconnect vacuum hose from brake booster.

40 Brake booster, removing and installing (Page 47-38) Vehicles with automatic transmission - Remove connector -1- from retainer Separate connector -1-. All vehicles - Remove trim below instrument panel. - Remove bolts Remove cover -A-.

41 Brake booster, removing and installing (Page 47-39) - Remove connecting plate between clutch and brake pedals on vehicles with a manual transmission. - Remove brake light switch Separate brake pedal from brake booster Page Guide brake booster with brake master cylinder out forward and remove. Installing Install brake booster in reverse order of removal. - Adjust brake light switch. Repair Manual, ABS, ABS/EDL On Board Diagnostic (OBD), Repair Group 01 - After installing, bleed brakes Page and clutch. Repair Manual, Manual Transmission 02J, Repair Group 30