DISCLAIMER2020 Porsche Boxster S (986) F6-3.2L Technical Service Bulletin # 6/01 Date: 020308
Brake Booster - Firewall Seal Modification
Boxster
6/01 4770
Binder - Group 4 Running Gear
Date:
3/8/02
Brake Booster Seal at the Firewall Changed
Vehicle Type:
Boxster / Boxster S
Model Year:
From 1997 (V) to 2000 (Y)
Concern:
Brake booster seal at firewall has changed.
Information:
Due to a modification in the body firewall, the brake booster bellows and seal at the body fire wall was changed during model year '00 (Y).
Replacement brake boosters are only available with the latest style bellows.
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The vehicles that will require modification when replacing the brake booster were produced before September 13, 1999, starting with the VIN
numbers shown.
In order to install the brake booster with the latest style bellows in these vehicles, you must order the parts listed below (in bold). When performing
the modification to MY'97 vehicles, the brake pedal will also have to be replaced.
Part Numbers
Working Time
Literature:
Boxster Technical Manual, Groups 4 and 9:
Repair: 47 70 31 - Converting brake booster (Supplement 51)
Repair: 46 05 19 - Removing and installing the brake pedal.
Group 9 - Work instruction after disconnecting the battery.
Attachment:
Excerpt from Boxster Technical Manual:
47 70 31 - Supplement 51 Converting brake booster (bellows)".
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DISCLAIMER
Work Procedure
When installing a brake booster (996 355 923 00) with new bellows and seal in a vehicle produced before the introduction date specified, the
vehicle must be converted to the new seal.
The procedure is outlined in (soon to be released) supplement 51 for the Boxster Technical Manual, in Group 47 70 31.
The corresponding chapter in the Technical Manual (included in supplement 51) is enclosed with this Technical Information. Please use that for the
bases of the repair.
Note:
The following applies to MY'97 (V) Boxsters only:
In addition to the parts listed, in cases where the new brake booster with new seal is installed in vehicles of the model year '97 (V) for the first time,
the brake pedal (Fig. 2 shown item 14.1) must also be replaced.
The installation of a new brake pedal in the '97 model is necessary, as it is connected to the push rod by a self aligning bolt (Fig. 2 item 16) with a
diameter of 12 mm and a tab washer (Fig. 2 item 15).
As of model year '98 (W), the connection is made using a threaded pin (Fig. 2 item 16.1) with a diameter of 13 mm and a threaded bushing (Fig. 2
item 15.1).
The clip (Fig 2 item X) is no longer used in the new connection.
The following procedure is a short overview of the work to be carried out. Use the enclosed work procedure from supplement 51 to perform the
repairs.
1. Position vehicle on lifting platform and raise.
2. Remove all wheels (after conversion, the brakes must be completely bled).
3. Remove battery.
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4. Remove brake booster (Fig. 1 shown item 4) with brake master cylinder. To do so, the hydraulic unit, and in the case of vehicles with PSM,
the booster pump must also be removed.
5. Remove bellows and rubber grommet (Fig. 2 item 1, 2, 3), brake push rod (Fig. 1 item 9) and intermediate piece (Fig. 1 item 11).
6. If necessary, completely remove the sealing ring at the opening in the body firewall.
7. Insert the sealing ring (Fig. 1 item 7.2) without lubricant in the opening in the body firewall.
8. Insert the connecting piece (Fig. 1 item 7.1) with rubber lubricant into the sealing ring (Fig. 1 item 7.2).
9. Mount the sealing ring (Fig. 1 item 7.3) onto the connecting piece (Fig. 1 item 7.1).
10. Install the intermediate piece (Fig. 1 item 11).
11. Install new brake pedal in vehicles of model year '97, if necessary.
12. Install a new brake push rod (Fig. 1 item 9.1), using a new pin and a new threaded bushing. The brake push rod must be replaced because the
double rib (Fig. 2 item 9, arrow) for the grommet uptake on the previous brake push rod brushes against the new seal.
13. Mount the new push rod (Fig. 1 item 12.1) with hexagon nut M6 (Fig. 1 item 13.1) on the brake booster (Fig. 1 item 4). It is only necessary
to replace the push rod (Fig. 1 item 12) when the tab washer (Fig. 1 item 13) is installed. Set the push rod on the brake booster to the basic
setting.
14. Install brake booster (Fig. 1 item 4) and brake master cylinder with mounted bellows (Fig. 1 item B) and tightly fastened clamp (Fig. 1 item
6).
15. Connect the brake push rod (Fig. 2 item 9.1) and the push rod (Fig. 1 item 12.1). To do so, mount the hexagon nut (Fig. 1 item 13.1).
Overview of work to be carried out (ctd.; Fig. 2 item nos.):
16. Check or adjust the position of the brake pedal. Check the stop light switch setting.
17. Position the bellows (Fig. 1 item B) on the connection sleeve (Fig. 1 item 7.1) and secure with the hose clamp (Fig. 1 item 6.1).
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18. Install hydraulic unit and booster pump (in vehicles with PSM).
19. Install battery.
20. Bleed brake, ensure that the vehicle is correctly re-equipped, and perform the necessary tests (Boxster) Technical Manual or details in the
enclosure to this TI, Group 47 70 31, Supplement 61.
21. Perform the work made necessary by disconnection of the battery (Technical Manual = Repair Group 9: Work instruction after disconnecting
the battery).
22. Remove vehicle from the lifting platform.
23. Perform function test on brakes before leaving the lift vehicle hoist area.
Information
^ 2 bellows variants have been installed as standard in the Boxster, (first version -A- and new/current version -B-).
^ The bellows variant of the first version -A- is no longer available as a spare part. The version must be installed in the event of repair -A1-
(conversion described as shown).
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Note!
The conversion described as shown only applies for vehicles in which the bellows first version A (with 2 rubber bellows -1 and 2-) is installed!
Overview of Bellows Conversion
^ To convert the bellows variant -A- to version -A1-, the hydraulic unit, the brake booster -4- with brake master cylinder and the intermediate
piece -11- must be removed.
^ The assembly of the brake master cylinder with the brake booster -4- must not be disconnected for removal and installation if both parts should
be continued to be used!
^ To remove the intermediate piece -11-the battery must be removed! This will prevent damage of the components in the surrounding area.
^ The following parts must be exchanged or replaced for first installation of variant -A1- (replacement):
- Remove short bellows -2- on the brake booster and the long bellows -1- on the firewall.
- Remove the grommet (rubber groove ring) -3- for mounting the long (former) bellows (not replaced).
- The following parts are used in place of the removed parts -1 / 2 / 3-: Bellows -B- (already mounted on new brake boosters), connection
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sleeve -7.1- with sealing ring -7.3- the seal for the firewall -7.2- and the hose clamps (clamps) -6 and 6.1-.
- The two push rods -12 and 9- are to be replaced with the modified version -12.1 and 9.1-.
- Additional assembly - Boxster model '97: The brake pedal must be replaced in addition to the new push rod -9.1- in Boxster model year '97
--> "Additional assembly - Boxster model '97" in 47-6.1.
Difference in the push rods:
^ Push rods -12.1- with thread and fastening nut -13.1- in place of push rod -12- with retainer -13-.
^ A guide for the bellows -arrow- is present in the previous push rod -9-. A guide is not present and not permissible in the new push rod -9.1-!
Removal
1. Switch off ignition. Remove cover -A + B- and battery cover.
2. Remove spare wheel.
3. Remove brake booster -C- --> 47-6 Removing and installing brake booster".
Note!
^ The brake master cylinder -B- and the hydraulic unit -D- must be removed to remove and install the brake booster -C-.
^ The assembly of the brake master cylinder -B- with the brake booster -C- must not be disconnected for removal and installation if both parts
should be continued to be used!
4. Remove battery -1- (necessary to remove intermediate piece -11-). Remove alarm horn on the intermediate piece -11-.
5. Undo intermediate piece -11- -arrow- (2 M8 nuts and hexagon socket head bolt) and remove in the direction of the battery. Unclip
air-conditioning line -2- from the holder.
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6. Remove the bellows -1- on the fire wall and the bellows -2- on the brake booster. Pull off the grommet (rubber groove ring) -3-.
Note!
The grommet -3- is not replaced!
7. Undo brake pushrod -9- on the brake pedal and remove.
Note!
The former brake pushrod -9- with guide (double rib) -arrow- is to be replaced with the brake pushrod -9.1- without guide!
Additional assembly - Boxster model '97
^ Brake pedal -14- must be replaced by -14.1- in addition to the new push rod -9.1- in Boxster model year '97. The figure shows 1 brake pedal
with old -14- and new -14.1- push rod connection.
Note!
^ Installation of the new brake pedal -14.1- is necessary as the connection to the push rod in model '97-9-is made with a pin (self-aligning
bolt) -16- with a mechanical locking device -15-. Connection as of '98 model: Threaded bolt -16.1- with threaded bushing -15.1-.
^ The new brake pedal -14.1- is fitted with a bearing (pressed in) (at the connection to the push rod) while the brake pedal of model '97 -14-
tin this area) is fitted with a bushing.
^ The clip -X- on the push rod of model '97 -9- is not included!
- Remove the brake pedal and install new brake pedal --> 46; Rep. Gr. 46 05 19; Remove and install brake pedal. Allocation/ part numbers
are to be referred to in the Technical Information notice, Gr. 4 number 6/01.
Fitting
Caution!
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Material damage to the connection to the brake pedal if the tightening torque used on the connecting pin is too great!
^ It is essential to observe the specified tightening torque on the connection thread bushing/pin!
1. Install new brake pushrod -9.1-. Tighten the threaded bushing -arrow- of the pin to 10 Nm (7.5 ft.lb.) (Please observe)!
2. Insert seal -7.2- (without lubricant) into the firewall. It is essential to ensure correct seating! Then insert (push in) the connection sleeve -7.1-
into the seal -7.2- using rubber sliding compound for example Capella or tyre mounting paste. Recheck that it is seated correctly and correct
if necessary!
3. Mount seal -7.3- and coat with Capella or tyre mounting paste.
4. Mount intermediate piece -11- (2 M8 nuts and hexagon socket head bolt). Tightening torque of the 2 M8 nuts = 23 Nm (17 ft.lb.)
5. Install battery.
6. Install new pushrod (if not already present) -12.1 - in place of -12-. When doing so, observe installation dimension X (138 mm).
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Basic setting of the push rod -dimension X- is 138 mm (set in new brake boosters)! If necessary, correct during the relevant work!
7. Install brake booster and brake master cylinder with mounted bellows -B- and tightened clamps -6-.
Note!
Before using the brake booster, push the screw clamp -6.1- onto the bellows -B- or onto the brake pushrod!
8. Tighten fastening screws of brake booster (Torx T 45) -arrow- to 23 Nm (17 ft.lb.). Fit the vacuum line for the brake booster.
- If the brake master cylinder has been removed, tighten the fastening nuts (M14) to 49 Nm (36 ft.lb.).
9. Connect the 2 push rods. To do so, mount the fastening nuts -arrow-.
Note!
^ Adjusting the brake pushrod length changes the position of the brake pedal.
^ Perform a fine adjustment of the brake pushrod if the correct position of the brake pedal is not given!
^ After the brake pushrod is adjusted, check the brake light switch adjustment!
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10. Check the position of the brake pedal -Dimension X 45 + 5 mm-. Perform measurement between the centre of the brake pedal plate and the
accelerator. Perform a fine adjustment of the brake pushrod if the correct position of the brake pedal is not given.
- Precise adjustment of brake pushrods: Undo the lock nut for this purpose and the turn the push rod accordingly at the hexagon -arrowuntil -dimension X 45 + 5 mm- has been achieved. Subsequently re-tighten the the lock nut.
11. Check the setting of the brake light switch -1-.
The pedal must move a perceptible distance of approx. 5 to 10 mm before the brake light, lights up. At the same time, check (make sure) that
the brake light, lights up before the pedal meets perceptible resistance or before brake pressure builds up. If necessary, set.re-adjust --> Rep.
Gr. 46; Check brake-light setting.
12. Fit the bellows -B- to the connection sleeve -7.1- and secure with the screw clamp -arrow-.
13. If necessary, fit the alarm horn to the intermediate piece and clip in the air-conditioning line.
14. Install hydraulic unit.
15. Bleed brake Serv. No. 47 01 07 (vehicle with and without TC).
Note!
^ First bleed brakes as usual!
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^ Only after the conventional bleeding should the return pump actuation be performed (continue bleeding) with the Porsche System Tester 2
in vehicles with TC (Traction Control)! If this is not observed, damage can occur to the return pump/booster pump!
^ To bleed at rear on right with running return pump motor (TC), the bleeding device should remain connected and switched on! Bleeding
pressure approximately 2.0 bar!
16. Bleed the clutch in manual transmission vehicles --> 30; Rep. Gr. 30 01 07; Bleed the clutch system.
17. When replacing the hydraulic unit in vehicles with ABS/TC (4- channel system), code the control module (manual transmission or Tiptronic).
18. Carry out the following tests:
- Check the system (brake lines and connections) for leaks.
- Read out and erase the fault memory of the ABS control module with the Porsche System Tester 2 (PST 2). Additionally, perform the
static test in the system.
- Check electrical and hydraulic lines (brake lines) for incorrect assignment using the PST 2.
Note!
The exchange test checks that the brake lines/solenoid valves are assigned to the correct brake calipers (wheels)!
- Then start the engine. The ABS or ABS/TC related lights in the instrument cluster must go out when the engine is running.
- Carry out a function check of the brakes. Then perform a short test drive and perform at least one ABS control operation, taking the road
conditions into consideration. Read out the ABS fault memory again. There must not be any stored faults.
19. Perform the work which is necessary due to disconnecting the battery --> Rep. Cr. 9 ; Work instruction after disconnecting the battery.
20. Fit cover -A/B- and spare wheel.