Yep inline V45, lives in front of the pedal box (RHD) , yes tracked all the lines and yes definitely only fronts, and it's only boosts the front line from a tandem master. I did consider removing it but I figured Id try it before removing it. And it only puts in a small amount of boost, and it could have been installed due th brake balance being out and I also learnt a lady used to drive the car and I can only gather it was at here request. It could be depriving the force to the rear and hence the fronts are getting hotter than they should, food for thought. Might try taking the vacuumed off and doing some test brakes, to see it the rear lock first.