I have a 2004 corsa life with a wet carpet in the drivers footwell, front and rear. The most obvious leak point is the servo backing plate. This is the large black plate that bolts onto the bulkhead. the answer is to re-seal this plate. it is first done when the car is built, but after 5 years the seal perishes and lets water in during heavy rain, even when the car is parked. You can clean out the drain holes in the compartment beneath the scuttle plate, but that isnt really the problem. Remove the windscreen wipers.Lift the bonnet. Disconnect the battery leads for safety. Then remove the scuttle plate, it is the black plastic vent at the bottom of the windscreen.To remove the scuttle, take out the retaining screws, then pull the unit back, and lift up in the same movement. After that, its a case of removing the washer bottle, it just lifts up and out, but take the plug lead off first, it just unclips. Then suck out the brake fluid in the plastic reservoir, and then remove the reservoir. After that it is the turn of the servo. I am going to have a go at this myself, but it will require the servo being disconnected from the brake pedal inside the car. This requires the removal of a retaining clip and a return spring. Lets be honest, this isnt a job for just anybody, but THIS IS where the water is getting in, in the drivers footwell. A mechanic can do this job, but I would not go to a main dealer. Shop around, cos it is a relatively easy job for a mechanic. Once the servo is off, you will see a large black backing plate on the bulkhead, with sealant around the edge. This will be perished, and THIS IS where the water gets in. Scrape the old sealant off, and thoroughly clean the edges. Then apply a rubberised sealant or underseal, liberally, don't skimp. When it is dry, try spraying a hose over it for half an hour, and see if it is still leaking. I have been assured that if sealed correctly, it WILL stop the leak. I must stress, I have yet to do this myself, but in a few days I will have a go when I'm off work. I am planning to cover the seal with a waterproof gaffer tape when it is dry, as a further defence. Hope this explanation at least sheds some light on the problem. might save you from spending a bomb at a dealer to be fobbed off and still end up with wet carpets. lovely little car if sorted. Balls to Vauxhall, they know what the fault is, its been there for years and they have done nothing to try and cure it
stevieboy, January 2013