I would almost gurantee that your water leak is behind the fuse box or even the brake booster, the only reason I say this is because I have repaired five that were rusted behind the fuse box, rusted at the fire wall The only way to fix this properly is to remove the parking brake assembly foot pedal assembly and the underdash insulation now you can see your problem, if you unfasten the wire harness strap holders you can now go under the hood and remove fuse box cover and unscrew the fuse box blocks do not remove the wires from the blocks unless you make a schematic so you know where the wires go, but what i recomendis gently pulling blocks out of fuse box now go inside and remove the four nuts that fasten the fuse box to your fire wall now go back outside and thread the fuse blocks back through the box you will have to cut one or two wires just remember where they go. see the rusted fire wall thats your water leak you can take a peice of sheet metal cut to size and rivet it in place use a good sealent to seal it up, good luck a lot of work but well worth the effort you proably have rusted floor board on driver side too all cuased by leak behind fuse box, Jerry, Master Mechanic