Fast Car – July 2019

(^6) PADS
Grab your new pads and work out which ones go where. In our case it’s
obvious because the pads have a retaining clip that fi ts into the piston, but
that’s not always the case. Some also have an electronic wear sensor that
will need to be plugged in – that is unless the car doesn’t have the facility
to monitor them in the fi rst place, in which case you’ll need to cut ’em off.
(Note: BMWs and MINIs often have a separate sensor that needs to be
plugged into the pad and then the dash indicator reset).
Before you fi t your pads, slap a little copper grease on the edges where
they make contact with the calliper or carrier, to help prevent squeaking
and seizing. For obvious reasons, be careful not to get any on the disc or the
pad friction surface.
Once the pads are mounted, the calliper can be bolted back on in the
reverse of how you took it off. Don’t forget any metal retaining clips and
be careful not to over-tighten the bolts as they’re usually small and easily
snapped. Most people don’t, but it is best to refer to the manufacturer’s
torque settings here.
(^7) BEDDING-IN
Once you’ve put the cap back on the fl uid
reservoir, you’re done for now (unless you’re
doing the rear discs and pads too). But bear in
mind that you’ll need to bed your pads in over
the next 100 miles or so. That means smooth,
progressive braking until the friction surfaces
are mated together perfectly for optimum bite.
There you go. Better stopping in no time at all!
(^5) PISTON
Now you’ll want to give the calliper a good clean
with your wire brush and brake cleaner, to remove
any old brake dust and debris. But don’t go too mad.
Make sure you don’t pop off and lose any metal
clips that are on the calliper or carrier. You’ll be
needing those.
Because your old pads will be more worn (and
hence thinner) than your new pads, you’ll also need
to push the piston back into the calliper housing
to account for the extra thickness. For this you’ll
usually need a big pair of water pump pliers or a
specialist piston winder. This is also the bit where
you get to pray your pistons aren’t seized out. Each
one should slide back in smoothly.
048 http://www.fastcar.co.uk