Brake Pedal Assy: Service and Repair
Removing and installing brake pedal
Important notes
The description below applies to left-hand drive vehicles with manual transmission or Tiptronic. On Tiptronic vehicles, start removal with No. 7 (stop light switch/area B). Pedal bearing axle (No. 13) is shorter because there is no clutch pedal lever.
On right-hand drive vehicles, the clutch pedal lever is located directly next to the brake pedal (separated by the steering outer tube in the case of left-hand drive vehicles).
Assembly/disassembly for right-hand drive vehicles is similar to the procedure for left-hand drive vehicles.
Before the start of disassembly work on the pedals, the clutch boost spring must be fixed with a cotter pin (arrow at No. 5) in the case of vehicles with manual transmission.
Important: secure the cotter pin (bend it over).
Pedal-group versions (distinction)
1. The pedals of Boxster vehicles as of Mod. '98 (as of Mod. W) are identical to the 996 pedals, with the exception of the boost spring and boost-spring bracket.
2. The Boxster pedals before Mod. '98 (before Mod. W) differ from the pedals as of Mod. '98 in the following respects:
- Bracket for clutch boost spring cannot be unscrewed. Consequently, the boost-spring bracket cannot and need not be adjusted. Furthermore, the distance between the bearing pins of the boost spring is 3 mm less
- Pedal bearing axle with different fastening method >arrows< (clamping of the steering outer tube and fixing of the pedal-bearing axle)
- No return spring on the brake pedal
Part 1 Of 3:
Part 2 Of 3:
Part 3 Of 3:
Illustration and notes for brake pedal removal and illustration
Removal
Warning Danger of injury and damage during disassembly and assembly work! Clutch boost spring can disassemble automatically!
> Before the start of disassembly work in the area of the clutch pedal lever (exception: clutch pedal switch), the clutch boost spring must be fixed with a cotter pin (refer to illustration at step 10).
1. Disconnect battery ground cable.
2. Remove driver's seat (to facilitate work).
3. Remove air duct (A). The air duct is plugged in.
4. Detach diagnostic socket.
5. Detach relay carrier, unclip and lower into the footwell.
Note Continue with Step 11 for Tiptronic vehicles.
6. Release clutch pedal switch by turning it 90° and pull it out of the installation opening.
7. There is an assembly bore in the guide rod for the clutch boost spring. Insert a 3 mm cotter pin in this bore, and bend over the ends (securing: refer to illustration for step 10).
8. Remove pin between the clutch push rod and clutch pedal lever.
9. Remove retainer (1) on the pedal bearing axle.
10. Undo fastening nuts from boost spring bracket (arrows).
Requirement: Boost spring secured with a cotter pin.
Remove clutch pedal lever together with boost spring and bracket. The bracket is not removable on the Boxster before Mod. '98.
11. Release stop light switch by turning it 90° and pull it out of the installation opening.
12. Disengage return spring for brake pedal at the body (not present on vehicles before Mod. '98).
13. Remove pin between the brake push rod and brake pedal.
14. Undo lock nut (2) for fastening the steering outer tube C; (refer to illustration at step 9). Undo hexagon nut (3). Unscrew (remove) pedal bearing axle (4).
15. Pull out brake pedal. To do this, turn the brake pedal and/or brake push rod accordingly.
Installation
1. Inspect all bearing bushings X for clutch pedal lever and brake pedal and replace them if necessary. Lubricate sliding surfaces of the bearing bushings X and the pedal bearing axle with Optimol, Optitemp LG 2, part No. 000.043.203.37.
2. Fit brake pedal and stop light switch. Tightening sequence of the pedal bearing axle (refer to illustration).
No. 4 = Pedal bearing axle (8 ... 10 Nm (6.0 ... 7.5 ft. lbs.) No. 3 = Hexagon nut (10 Nm (7.5 ft. lbs.)
No. 2 = Lock nut for steering outer tube (20 Nm (15 ft. lbs.) / before Mod. '98 = 30 Nm (22 ft. lbs.)
Note Stop light switch installation and stop light switch adjustment.
3. Assemble boost spring, bracket and clutch pedal lever. Description in 3.1 or 3.2.
3.1 Boxster Mod. '98 / partly Mod. '99
3.2 Boxster from current Mod. '99
Note
Different types of boost springs can be fitted in the Boxster. Observe proper allocation when replacing the boost spring and/or the bracket.
In some cases, a modified (optimized) clutch pedal must also be used when replacing the boost spring.
Lubricating the boost spring bearing surfaces is sometimes necessary and sometimes prohibited (according to boost spring version).
3.1 Boxster Mod. '98 / partly Mod. '99
Identification/distinction:
Boost-spring push rod open on one side, boost spring components not coated.
Grease pin for boost spring (arrow) with mating bearing on the boost spring push rod, the boos spring bearing (arrows) and the bearing pins on the boost spring with Optimal, Optitemp LG 2, part No. 000.043.203.37.
First remove old grease with solvent naphtha.
3.2 Boxster from current Mod. '99
Identification/distinction:
Push rod closed / boost spring components coated.
The date of introduction for this boost spring is contained in the Parts Catalogue.
Engage the hexagon-socket bolts of the boost spring into the hexagon on the clutch pedal (arrow).
Important: Do not lubricate since the sliding surfaces of this boost spring version are coated. 'Do not lubricate' applies to all sliding surfaces (boost spring pins, boost spring bearing in the bracket, bearing pins on the boost spring, and the boost spring in the boost spring pot).
Note Silver bracket (986.423.571.00) and boost spring with white marking (986.423.081.08 Mod. '98 / partly Mod. '99 or 986.423.081.11 from current Mod. '99) must be used only in this combination and installed only in the Boxster.
4. Installation and adjustment specification for boost spring bracket. Install preassembled boost spring bracket with clutch pedal lever. Valid only for Boxster vehicles before Mod. '98 (bracket cannot be unscrewed or adjusted).
To do this:
Step 1: Tighten the three fastening nuts (arrows) only slightly (the bracket must still be movable).
Step 2: Tighten the clutch master cylinder to 10 Nm (7.5 ft. lbs.) (if the clutch master cylinder was detached).
Step 3: Press the clutch pedal against the direction of travel until the pull stop in the clutch master cylinder is reached.
Step 4: Remove cotter pin (retaining pin) on the spring cup so that the clutch pedal is pressed against the rubber stop in the boost spring bracket.
Step 5: The bracket is screwed down with the clutch pedal pressed back (to make full use of the slots). Tighten hexagon nuts (arrows) in the prescribed sequence. Tightening torque: 7.5 Nm (5.5 ft. lbs.).
Sequence: 5a / 5b / 5c
Note The push rod of the clutch save cylinder should not be lubricated in general (for all versions).
5. Fit new retainer on the pedal bearing axle. On vehicles as of Mod. '98, subsequently secure the retainer by wedging it with a mandrel.
6. Install clutch pedal switch. First pull operating plunger out of the switch as far as it will go. By means of its self-adjustment function, the switch then compensates for tolerances in the pedals.
7. Check the interlock switch adjustment on vehicles with interlock.
Adjustment specification for interlock switch:
The switch must be aligned so that, with the clutch pedal depressed, it is operated approximately 1 to maximum 2 mm before the limit stop of the clutch slave cylinder is reached.
8. Install relay carrier, diagnostic socket and air duct.
9. Perform a function test on clutch and brake operation.