Removing and Installing Pressure-Operated Switch

Removing and installing pressure-operated switch (tire pressure warning system)

Important note/preparation

The tire must be removed from the rim before removing or installing a pressure-operated switch. The following points must be observed under all circumstances when dismounting or mounting the tire:
- Clean dirty wheels before removing the tire Mark the position of the tire on the rim for reassembly.



- Apply the forcing blade of the tire mounting unit at the central point between both pressure-operated switches. The deflector (arrow) must remain fitted while removing and fitting the tire to protect the pressure-operated switch.
- The diaphragm of the pressure-operated switch must not come into contact with grease, tire assembly paste or similar under any circumstances.
- Always replace the fastening nuts and torroidal sealing rings for the pressure-operated switches.
- The tire inflation pressure must not exceed 6 bar in order to present damage to the pressure operated switch.


Removing and installing pressure-operated switches

1. 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 new fasten nut by hand.

Call on the services of a second mechanic to counter the pressure-operated switch while you tighten the fastening nut. Tightening torque for the fastening nut 20 Nm (15 ftlb.)

Note: The pressure-operated switch must not turn while tightening the fastening nut. (Damage to the seal/leak).




1 Tool to counter (9273)
2 Pressure-operated switch with seal. Specified pressure front 2.5 bar / rear 3.0 bar or 2.5 bar
3 Fastening nut
4 Tool to tighten (9274)

4. Remove protective foil from the diaphragm side if necessary. Press deflector onto the fastening nut and adjust. Check for secure fitting.

5. Mount tire (max. 6 bar tire pressure) and balance wheel.

6. Mount wheel onto hub and carry out quick test for tire pressure warning system.