Brake pedal adjustment.

[riothamos@gmail.com]

Hello All..this mite seem a simple question.
Symptom. My brake lights are on constantly due to the brake pedal having alot of slack.The brakes work fine,no other faults.
Q. Is there adjustment for the brake pedal (auto) on my S Type R as it causes the switch to be on all the time.
If you hook your foot under it the switch releases (switch works fine).
Cheers
R

[J44EAG]

The slack is probably caused by wear which needs to be cured before you look at switch adjustment. The fault requires attention before looking at the symptom. That said, pedal switches can also be problematical given age and mileage. The two issues should perhaps be investigated to find the root cause.

Mike K

[riothamos@gmail.com]

Re: S Type brake pedal adjustment.
Upon further examination,despite the brakes working fine it seems there is more to it than pedal adjustment as you guessed.
The pedal is hard until you start the engine, the pedal dips, rises again but then slowly drops again until it rests on the switch (activating the brake lights)..I would guess it is a servo issue but that is about the limit of my mechanical knowledge.
A new Servo? Servo repair kit? Something else?...your thoughts please.
Regards
R

[J44EAG]

That sounds rather like master cylinder pressure loss possibly due to worn seals. With worn seals, one has to be certain that the cylinder bore is also not scored or worn. Most people would replace the complete master cylinder with a new component rather than attempt a repair. A new unit is likely to be vastly more reliable than a high mile old component even when fitted with a new seal kit...and you need good brakes more than anything else. A sinking brake pedal implies a worn master cylinder.

Mike