Conventional adjustment of tire pressure

If the Pressure Loss fault display appears, tire pressure at the affected wheel must be increased by 0.3 bar or at least to the specified pressure at that wheel. Since diffusion losses are approximately the same at the two wheels on any one axle, the tire pressure at the other wheel should therefore be increased by the same amouint. But do not reduce the tire pressure if too high a value is measured. The specified tire pressures at 20C are front 2.5 bar, rear 3.0 bar 2.5 bar for 17 summer...

Checking and correcting tire pressures

When tire pressures are corrected, a distinction has to be made between the conventional method (method A) and the more accurate method in conjunction with the 9288 system tester (method B). Do not check tire pressure by the conventional method (method A) unless pressure loss has been Indicated on the Instrument panel. By using the 9288 system tester, however, tire pressure can be checked and accurately adjusted at any time (method B). This is practicable during wheel and tire fitting work or...

Important notes on the diagnosis and assessment of RDK faults

When the RDK control unit plug Is disconnected, the display panel shows RDK SHUT DOWN after the engine has been started. This display is supplied from the instrument panel. If a wheel without a pressure sensing switch is fitted to the car, TIRE PRESSURE LOSS appears on the display panel after a short time, and the affected wheel is Indicated by an arrow. The system fault display takes precedence over the pressure loss display (in the event of pressure loss and an RDK fault, the RDK system is...

Tire pressure warning system

Two pressure-sensitive switches are allocated to each wheel, fitted to the rim well, 180 apart. The pressure-sensitive switches are subjected to the tire inflation pressure and act as switches for a resonant electric circuit, integrated into the pressure- sensitive wjtch- The resonant circuit remains closed as long as the tire inflation pressure remains above a specific setpoint value for the switch. If the inflation pressure drops below the setpoint value, the pressure-operated switch opens...

Tire pressure warning system General General

A tire pressure warning system is fitted to 928 S 4 vehicles as standard, from Mod. 1989 onwards, initially excluding USA and Canada, however. The tire pressure warning system is another development which constitutes a significant contribution towards road safety. The tire inflation pressure is monitored by the control system, which - monitors the correct Inflation pressure with a greater degree of accuracy and reliability than any pressure tester in the on-board tool set, at the garage or in...

Bear In mind that it is possible to get even better results from the point of view of smooth running in some cases

Cast tight-alloy disk wheels must not be fitted to the vehicles with four-piston fixed calipers (as from Model 86). Club Sport version wheels (larger cutouts) have a different rim offset (see Page 44-01). New tires should always be fitted to the front axle wherever possible (if the same wheels are fitted to rear and front axles), as 1. the rear axle is more critical with regard to stability, and 2. in wet conditions, the front wheel must first steer a course which the rear wheel can follow to a...

Always use new rubber valves when replacing tires

Attention When fitting tires, always comply with any Instructions on the side walls with regard to direction of rotation or side-specific assembly (e.g. arrow or outer Inner) When fitting tubeless tires, check that the sealing areas of the tire and the disk wheel are clean and look for any damage. With regard to this, always bear in mind that a tubeless tire is sealed by the bead base. If the side wall of the bead were used for sealing, it would be possible for air to escape under extreme...

Track difference

It is not possible to adjust the track difference (can only be affected by replacing steering arms). Refer to drawing for lateral and radial runout measuring points on inside of rim. Max. permissible lateral and radial runout on aluminum rims 1,0 mm Max. permissible lateral and radial runout on rim with tire 1,25 mm (also refer to page 44 - 8) Damaged rims should never be straightened. Check flanges of aluminum wheel rims for wear. The inside rim flange is more subject to wear. Use a standard 8...

If vehicles have aluminium joint carriers

Always turn the caster eccentric from small values towards large caster values, i.e. if the caster value is too high, first turn the eccentric back completely and then adjust to the correct value. This guarantees that the camber and caster values are always maintained, even under extreme operating conditions. If it is not possible to achieve the prescribed caster value, adjust the other side to the higher value if necessary (up to 4 degrees 30' is acceptable). Preparation Center steering gear...

Checkadjust height Note

The adjustment facility is used to correct differences between left and right wheel loads. If the height is correct, the differences in wheel load are within a permitted tolerance as long as the coil springs on each axle are the same length spring pretention). Tolerance 1 mm. It is possible to keep the differences in wheel load as low as possible if wheel-load scales are used. The tolerance between right and left on front and rear axles less than 20 kg. 2a) If spring struts are not adjustable...

Specimen measuring chart4

Rims and tir (damage and lr ad C'fte'en fl ongle ol 20 turning radiui Vefiicle Empty wsiqht according JIN 7C020 (wilh full fusl larw, apa 16 wheel and Rims and tir (damage and lr ad C'fte'en fl ongle ol 20 turning radiui Ca a heighl * noninai value 173 10 mm Ca a heighl * noninai value 173 10 mm load in kg* Max. difference oefween left arlO right 20 kg k Refer to instructions m Repair Manual * The caster adjustment setting has been changed for 1991 models on to 4' + V (previously 3 30' + 30')....

Specimen measuring chart

Diffsrertca angla ot 20 turning radius 0 2 10 tOe-in Vehicle Empty weight according 1c- DIN 7CO20 (with full fuel lank, spare wfr* i and loots) Diffsrertca angla ot 20 turning radius 0 2 10 tOe-in 20 right turn-in measured I ell Vehicle Empty weight according 1c- DIN 7CO20 (with full fuel lank, spare wfr* i and loots) Car's he g hi (nominal valui 190 - 20 mm Car's he g hi (nominal valui 190 - 20 mm * Refer to instructions in Repaie Manual * Refer to instructions in Repaie Manual * The caster...

Fitting and tightening procedures of all other wheel types 16inch Design 90 etc for stationary balancing remain

This means Coded stud, valve and locking wheel nut are located on the same side. When tightening, valve must point up (same position as on balancing equipment). It is recommended to add an extra refer-enceto the modified assembly in the Wheel balancing and General notes on fitting tires chapter. If required, mark the wheel stud located opposite the valve before removing the wheel. For stationary balancing of the wheels (with step rings), turn the wheel in such a manner that the valve points to...

Tire and wheel overview tire specification character

For a tire and wheel overview for summer and winter tires, refer to the relevant Technical Information (T ), Group 4. When replacing summer tires, check for the correct tire specification character. The specification characters N 0, N 1, or N 2, respectively, help to distinguish summer tires approved by Porsche from other versions of identical tire type and the same tire size. The tires approved by Porsche are also identified in the corresponding Tl. NO, N1 and N2 tires must not be mixed on one...

Tire pressure of cold tires approx 20C summer and winter tires 15 and 16 inch

2.5 bar pos. pressure 2.5 bar pos. pressure 2.5 bar pos. pressure 3.0 bar pos. pressure front and rear 2.5 bar pos. pressure for 8 PR 89 P 92 P tires front only 2.2 bar pos. pressure for 4 PR 83 P tires * Due to changes in standards and legislation, V and ZR tires require tire pressures that deviate from the values indicated in the Owner's Manual. Always use the new tire pressures indicated above. Relevant adhesive labels are available from all official Porsche dealers. ** In some cases, only...

Info

- The exploded drawing shows the front-wheel bearing arrangement of cars with sliding calipers. - If the front axle is equipped with floating calipers, brake caliper, brake disk, guard and steering knuckle are of different appearance and size. - The following components of four-piston fixed-caliper brakes differ in appearance and size brake disk, brake caliper, mounting bolts for caliper, outer wheel bearing, wheel hub, guard and steering knuckle. Mounting bolt (hex bolts for sliding and...

RDK Possible causes if a fault is indicated

Increase tire pressure at indicated wheel by 0.3 bar. Increase pressure at wheel on opposite side of same axle to the same pressure. Or Adjust tire pressures exactly with 9288 System-Tester (to 0.3 bar above the pressure-sensing switch trigger value). Tire wheel damage Display reappears at frequent intervals Leaking wheel rim or tire valve slow puncture in tire, damaged sealing ring at pressure-sensing valve. Fit the temporary spare wheel. Take car to Porsche dealer tire repair as soon as...

Accurate adjustment of tire pressures with the 9288 system tester

In view of tire pressure gauges' display tolerances and the difficulty of measuring the temperature of the air in the tire accurately, cars with what appear to be correctly adjusted tire pressures are very often only just above the switching threshold of the diaphragm-pattern pressure sensing switches. When a slight centrifugal force acts on the diaphragm at high speed, an entirely justifiable tire pressure warning is displayed. To avoid this problem, tire pressures in the workshop should...

Removing and installing relay General

The anti-lock system is fitted with three relays. The ABS relay (power supply for electronic control unit and scavenge pump motor relay) is located on the Central Electrical System. The relay for the solenoids and the relay for the pump motor are located below the cover of the hydraulic unit. 1. Flip up cover of Central Electrical System in the passenger's footwell. 2. With the ignition off, pull out and insert ABS relay, respectively (electronic relay with overvoltage protection). The relay is...

Psd

Possible fault displays via system tester 9288 DTC Fault type System allocation 11 Transverse lock valve PSD 12 Lateral acceleration sensor - PSD short circuit discontinuity 13 Lateral acceleration sensor - PSD signal implausible 14 Transverse lock - deviation PSD 15 Control unit - defective ABS PSD 21 Wheel speed sensor, front left ABS PSD 22 Wheel speed sensor, front right ABS PSD 23 Wheel speed sensor, rear right ABS PSD 24 Wheel speed sensor, rear left ABS PSD 31 ABS valve, front left ABS...

Checking Hydraulic Function of Steering Pressure Test Printed in Germany XXXIV 1994

REMOVING AND INSTALLING STEERING WHEEL 2. Mark position of steering wheel to steering shaft for reinstalling. 1. Install steering wheel with road wheels pointing straight ahead or according to disassembly mark in such a manner, that steering wheel spokes are horizontal. 2. Install hexagon nut with spring washer and tighten to specified torque. 3. Mount horn wires on impact pad and press impact pad on to retaining pins. 4. Check function of horns and direction indicator switch. X. Pull impact...

Tire pressure warning system RDK diagnosis General

- The system tester 9288 will be used for PORSCHE DIAGNOSIS from Mod. 89 onwards. PORSCHE DIAGNOSIS can be used for all systems capable of self diagnosis. Capable of self diagnosis means the control unit can detect, store and output system errors. Read out tire pressure loss event memory from control unit version R02 on introducing during 1991 model year . As the number of systems capable of self diagnosis will be increasing in the forseeable future, diagnosis of the relevant system will be...

Wheel alignment measuring data

The following values apply at empty weight in accordance with German DIN 70020 standard car with full fuel tank, spare wheel and tools . Measuring surface on rear control arm pivot Toe-out on turns at 20' steering lock Can only be varied by renewing steering arms From wheel contact patch to measuring surface on lateral subframe Height adjustment settings apply to new cars. After cars have been driven for a period the height may be max. 10 mm less, in other words the downward tolerance can vary...

Removing and installing pressureoperated switches

Turn the rim and clamp onto mounting unit. Remove the deflector from the pressure-operated switch. 2. Remove pressure-operated switch with Special Tool 9274 9273. Hold the pressure-operated switch with Special Tool 9273 while undoing fastening nut. 3. Fit the correct pressure-operated switch marked with specified pressure 2.5 - or 3.0 bar as follows Apply pressure-operated switch with new seal. Apply a film of Vaseline to the seal before fitting. Center pressure-operated switch and tighten...

Note

Use only brake fluid or brake cylinder paste as an aid to installation. Substances containing mineral oil will destroy the rubber elements In the brake system and cause brake failure. In the case of stepped brake master cylinders, there is a washer under the front sealing plug intermediate piston brake circuit . 4. Bleed the brake clutch with the filling and bleeding device. Check for leaks and for correct operation. 5.Remove cover and unscrew mounting nuts of brake booster. REMOVING AND...

Checking the ABS operation

If service operations not directly related to parts of the ABS have been carried out on the brake system, a simple functional check is sufficient. I.e. after starting the engine, the warning lamp in the instrument cluster must go off if the ABS system is o.k. Operations of this type include replacement of brake pads, brake hoses, brake discs, brake booster, tandem master cylinder, brake cables and components of the parking brake as well as brake pipes that are not screwed into the hydraulic...

Runout of removed

If the brake disc runout exceeds 0.1 mm, remove the brake disc and check runout of the wheel hub. Mark position of disc with regard to wheel hub. 3. Engage dial gauge holder, e.g. Ate Part No. 03.9314-5500.3 01, into brake caliper, determine center position and fit by turning the wing screw. If required, fit dial gauge holder with Ate conversion kit, Part No. 03.9314-5510.3 01 longer wing screw and bracket for dial gauge if required . Four-piston fixed...

All former steering gear versions are to be replaced with the current version 92834701027

The elastic steering stop, 928.347.329.03, for left and right sides is replaces by a solid steering stop, 928.347.329.04, for improvement in quality. At the same time it was necessary to replace the dust cover, 928.347.191.02, with a new version dust cover having a supporting lip, Part No. 928.347.191.03. Only the new steering stop 928.347.329.04 and the new bellows 928.347.191.03 are supplied for steering gear 928.347.010.24. The bellows 928.347.191.03 and the steering stop 928.347.329.04 are...

Dia left and right 23 mm

928.347.010.24 928.347.010.26 928.347.010.27 The steering gears with Part No. 928.347.010.22 former version and interim solution are no longer available. They should be replaced with the new current version. The steering gears of the new version 928.347.010.24 and 928.347.010.26 indicated in brackets have since been deleted as well status as of December, 1994 .

Installation

REMOVING AND INSTALLING SPEED SENSORS ON FRONT AND REAR AXLES 1. Take off front wheel. Remove intake hose on air cleaner. 2. Turn off ignition, take wire plug out of holder in engine compartment and disconnect. 4. Unclip wire on side member and in holders on steering knuckle. Loosen socket head screw and pull speed sensor out of steering knuckle. 3. Remove front exhaust shield to make procedures easier . Unclip wires on wheel housings and pull out with rubber grommet in direction of wheel. Also...

Important information on troubleshooting and ABS test program

Abs Led Tester

After certain repairs to the ABS system refer to functional check on page 45 - 07 , a test program using an ABS tester must be run. The ABS test plan, Print No. WKD 493 720, is required for this test operation and for troubleshooting. Following repairs affecting the ABS system cf. page 45 - 07 , a functional test using the ABS 2-LED tester must be run. 2 55-pin ABS 2-LED adapter lead. Same lead as for ABS testing on the 911 Carrera 4. Manufacturer and supplier Bosch. For address and order no.,...

If the 9288 system tester is connected make quite sure that no speed range is selected at the automatic transmission

Not all system faults are identified by the RDK control unit as faults. This applies to the RDK control unit itself. If the fault display RDK SHUT DOWN appears and no fault is stored in the control unit, the following points must be checked or confirmed before the RDK control unit is replaced a. Is the control unit plug attached correctly and are the connection contacts between the plug and the control unit in good condition b. When the ignition is switched on, a voltage higher than 9 Volt must...

Important notes for alignment

The following must be observed during alignment 2. Height setting alteration in wheel load Corresponds to the specified value. The tolerance range may be used to reduce the difference in wheel load. Should be within the tolerance range for the specified vehicle height. Is lost if the vehicle or front axle have been raised. Is recovered after a longer journey or longer operating period. Exact value can be achieved by pulling the front axle downward in a precisely defined way. Description in the...

Quick test of RDK

Whenever a wheel or tire is changed, it is essential to perform a quick test of the tire pressure control system. If only one wheel was removed, the quick RDK test need only be performed at this wheel. A short test drive for a distance of at least 20 meters, at a road speed of between 5 and 40 kph and at the following tire pressures is sufficient 1. Tire pressure 0.5 bar below nominal value front 2.0 bar rear 2.5 bar 2.0 bar for 17 summer tires The relevant arrow s must flash on the instrument...

Procedure for optimizing the wheels

The complete procedure is subdivided into 4 working steps 2. Stationary balancing of the wheel eliminating static and dynamic imbalance with optimization of smooth running 3. Fitting the wheel to the vehicle 4. Electronic fine balancing static balancing of the wheel on the vehicle after stationary balancing if required - not usually necessary Further to 1 Fitting the tire to the rim - Clean the rim above all, remove residua rubber and dried-on tire paste from the bead seat and the hump. -...

Technical Data Rear Axle

Wheel suspension Independent wheel suspension with lower diagonal suspension links and upper wishbones, coil springs and interna dampers. double-action hydraulic dampers page 42 - 18 d 0 22.5 x 3.5 mm tubular stabilizers modified in course of model year 1981 standard up to end of MY '91 Club-Sport-Version standard as of MY '92 Light alloy casting suspension link bearing for lower control arm 86 models onward to body Lower suspension link to transverse member camber eccentric Lower suspension...

Workshop Manual

Porsche 928 Lower Control Arm Bushings

PORSCHE Aktiengesellschaft TECHNICAL DATA Front Axle Suspension until end of model year 79 80 models onward 86 models onward control arm with coil spring and internal Double-action hydraulic dampers See page 40 - 51 dia. 28 mm x 4 tubular stabilizer with modified knuckle Spring strut and stabilizer linkage to lower control arm Stabi1izer clamp to longitudinal member Upper and lower control arms to steering knuckle Rubber bushing of piston rod of spring strut Ball joint,...