The likely candidate for rogue brake fluid in the centre after a pad change is simply fluid displacement from pushing the pistons back in to the calipers as it will over flow from the reservoir then run down the scuttle drains on to the gearbox and drip off in the middle, but that wouldn't cause a soft pedal.
How far did you have to push the pedal to seat the pads? Its not uncommon to find corrosion inside the master cylinder on older cars which haven't had a fluid change in a long time. Moisture builds up in the fluid and eats the inside of the cylinder, then when you push the pedal past its normal position the rubber seals are torn up by the corrosion and no longer hold pressure.
Concievably it could be a combination of displaced fluid and a failed master cylinder.
It may also be a split hard line. The two outputs from the master cylinder to the ABS unit and the line from the ABS to the driver's front caliper all run underneath the bulkhead. I'd say the most likely culprit is one of the two front caliper hard lines where they attach to the flexi hoses in the wheel arches as they suffer from corrosion at the union. A leak from those would be obviously on one side though rather in the centre.
Hmm, just re-read and a press of the pedal giving a new puddle does still suggest a hard line.
|