Stu and a Screw
Posted: Fri Aug 24, 2007 1:21 pm
A quick update on my braking issue.
You will remember that I had a problem with apparent disc warping and a grinding noise from the front left under moderate braking for the last couple of weeks after fitting new front pads.
Short story is that I had a bilateral front brake disc failure caused by 2 large crucifix shaped cracks extending from the bell to the braking surface on the outside of both front discs
.
This is because when I re-fitted the discs after replacing the front pads with Pagids, I did not correctly align the hole and remnant of the retaining screw (that had had the head drilled of the last time I replaced the discs at Lawrence's a year ago). This meant the the remnant of the screw was compressed between the hub and the disc and with wheel nut torque and cornering torque had dimpled the inside of the bell and cracked the outside.
Stu's sharp eye spotted this yesterday after he kindly offered to see me in the afternoon - and had dismantled the front left disc/caliper/pads in about 2 minutes.
Out of incredible fortune, Stu had 2 grooved fronts just like the ones that had come off and fitted these after cleaning the hubs, drilling out the retaining screw remnant, re-tapping the holes and re-fitting the brand new discs with new retaining screws. Incredible workmanship.
I don't have to tell you what might have happened had the crack suddenly propagated at speed and the disc completely fractured; perhaps instantly locking one front disc against the caliper doing 70 on the M8.....
Many thanks to Stu and a warning to all other novice racers and novice mechanics out there.
NR
You will remember that I had a problem with apparent disc warping and a grinding noise from the front left under moderate braking for the last couple of weeks after fitting new front pads.
Short story is that I had a bilateral front brake disc failure caused by 2 large crucifix shaped cracks extending from the bell to the braking surface on the outside of both front discs
.This is because when I re-fitted the discs after replacing the front pads with Pagids, I did not correctly align the hole and remnant of the retaining screw (that had had the head drilled of the last time I replaced the discs at Lawrence's a year ago). This meant the the remnant of the screw was compressed between the hub and the disc and with wheel nut torque and cornering torque had dimpled the inside of the bell and cracked the outside.
Stu's sharp eye spotted this yesterday after he kindly offered to see me in the afternoon - and had dismantled the front left disc/caliper/pads in about 2 minutes.
Out of incredible fortune, Stu had 2 grooved fronts just like the ones that had come off and fitted these after cleaning the hubs, drilling out the retaining screw remnant, re-tapping the holes and re-fitting the brand new discs with new retaining screws. Incredible workmanship.
I don't have to tell you what might have happened had the crack suddenly propagated at speed and the disc completely fractured; perhaps instantly locking one front disc against the caliper doing 70 on the M8.....
Many thanks to Stu and a warning to all other novice racers and novice mechanics out there.
NR
