I've always been very
happy with my big brake
upgrade way back in 2001. They were powerful and reliable.
The only problem I had with them was that the supplied Green
Stuff pads seemed to loose their bite and as a result they
had become a little wooden and lacking in feel They had
also started to squeal under light application. During the
early part of 2008 I bought some new pads to see if I could
bring them back to life. I went with Ferodo DS2500 pads
and they were very good, great bite from cold. The only
problem was they squealed just as much as the Green Stuff's
had been. I stripped and applied copper grease again but
they were the same.
During the Spain trip they were getting really noisy, whenever
I slowed down from 40mph or less they would scream my presence
to all nearby, which got a little tiring after a while.
It had got to the point where I was having to try to drive
around the problem, I would brake hard and then back off
and then brake hard again, as it seemed that the harder
I braked the quieter they were. It doesn't make for a very
smooth drive though, not great on a 500 mile, day long drive.
The next trip was Le Mans a month and a half later and they
were worse still, making a racket from seemingly any speed
now. Even the other se7ener's commented on it - so it must
have been bad! I lived with it for the rest of the year
but I wasn't happy and really couldn't find a solution that
I could try. I chamfered the leading edge of the pads, put
more copper grease on, etc, no change.
So, during the first drive of 2009 I had exactly the same
and it reminded how much it was annoying me and detracting
from having an enjoyable drive. I decided enough was enough
and managed to swing past the Caterham parts department
on a business trip to collect a set of the AP brakes. I
fitted these over the following weekend and bled the fluid
through a couple of times before heading out to bed the
pads/discs in. Initially they were scary, I could barely
stop at the end of my road which was a wake up call. I drove
carefully to the nearest duel carridgeway and made a couple
of runs of getting up to 60 - 70mph and then braking down
to 5 - 10mph before accelerating back up again - obviously
this can only be done with low traffic levels and with a
careful eye on the rear view mirror!! By the second run
up the duel carridgeway the brakes were coming good, the
pedal was a lot firmer and was offering stronger braking.
The only snag - at the end of the road was a roundabout
controlled by traffic lights. I was heading home and needed
to stop for some lights and the pedal went completely to
the floor. Fortunately I was still being cautious and was
traveling slowly and had left a big gap so had enough time
to pump the pedal which fortunately came back and I stopped.
The rest of the drive home was very cautious but I also
was trying to provoke the same to happen where I could safely
do so. It didn't do it consistently but it seemed that when
it did do it it was when you were gently braking, almost
pausing on the pedal. A hard shove and it was always fine,
the pedal was firm and didn't sink. I got home and checked
everything over and couldn't find a problem, posted on Blatchat
and thought it was probably the master cylinder seals. I
was pretty much resigned to having to buy a new one (£120)
when I was checking the rear bleed screws again and noticed
the inside of the rear wheel was wet. I pulled the wheel
off and found the slave cylinder was leaking - the only
reason I can think that I didn't spot this the first time
was that I backed the car in and at some point turned it
around and therefore checked the wrong side next. A new
cylinder was bought and the fluid bled through yet again
and no problems since. Phew!!
So, how are the AP's - well, great actually. They have OK
feel even with the standard pads and offer huge stopping
power, but I would like to try something with a bit more
feel, but I'll try to get some life out of these pads first.
They still squeal a little at slow speed when you are trundling
up to a junction or through busy traffic. Under normal braking
they are silent though. I will monitor as I am starting
to wonder if my hub is warped slightly as the noise isn't
a constant squeal, but rises and falls with the speed of
a wheel rotation. Argh - a job for the winter months I think,
the car is far too much fun at the moment.