When Z4Mariner requested more details regarding the inside bore measurements of the Pagid discs, I remembered that I’d taken a couple of photos of the Brembo discs prior to fitting, with a ruler across them in case I needed to reference them later on.
Both discs had the same measurement.
161mm.
So, why did the handbrake have virtually no effect, and was able to be more or less pulled fully up after fitting the Pagids yet the bore size was the same as the Brembos?
When I went to pick up the car after fitting the Brembo discs, my mechanic said yes, they fitted on beautifully but, unfortunately he had “popped” the handbrake so could I do a bit of research over the weekend as potentially this could mean removing the seats, carpeting, air bag modules and God knows what else to resolve the problem?
Not good news.
Needless to say my first port of call was to Google “BMW Z4 handbrake popping” which led me to the Forum and an explanation about the cable which has a hook on it which engages with the top of a spring but which needs to be disengaged once new shoes have been fitted…...
Anyway, my theory is that my mechanic had “half popped” the cable when he fitted the Pagid discs, but had fully popped it after fitting the Brembos resulting in no handbrake action at all.
After he’d fitted the Brembos and me having done my bit of research, I discovered the cable had hooked over the spring so I took a bit of a gamble with a couple of long screwdrivers and then, after a loud, springy twang sound………normal service was resumed.
So what I’m thinking is that:
After fitting the Pagid discs, calipers, pads and handbrake shoes, my mechanic could not understand why there was so much travel in the handbrake lever before it started to bite (unaware that he’d half popped the cable) and also the uneven nature of the brake when he took the car for a short run – he pulls the hand brake lever up for a short while as the car is moving to bed the shoes in. It’s what he’s always done.
You would definitely not want one of these as a front brake drum on a motorbike.
Don’t know if my theory holds up to any scrutiny but it’s my last throw of the dice on this one.
I have every faith in my mechanic but I think that maybe it was just one of those situations where two plus two seemed to make five. I’ve been there many a time.