My 2005 Cayenne 4.5S has ABS/PSM fault code 1276. I had the ABS pump unit checked over and it got the all clear about 8 months ago for a different issue. However, I now have fault 1276 but also, without any sign of brake fluid at any calliper or any sign of a leak there is a reasonably quick brake fluid drop. I have filled the reservoir from warning light to full three times in the last six months or so.
Combining these two issues, can anyone direct me to what parts need changing? Struggling to work out if master cylinder, vacuum servo assist or the ABS pump bl