One of the first steps in modifying our six
cylinder EF project Falcon was to improve the brakes. This was desperately
needed for two reasons: (1) when the car was purchased, the brakes had really
warped front discs, and (2) the brakes certainly didn’t inspire much confidence
in their retardation. A third reason was with the expected increase in engine
power, it made sense to have the brakes ahead of the rest of the package.
After looking around for big brake upgrades (there
are a few but they’re mind-bogglingly expensive) we decided to stick with the
standard sized discs and pads, but upgrade the quality of both.
After having good experiences with our Prius with
upgrade RDA discs and EBC ‘black’ Kevlar pads (see
DIY Brake Upgrade, Part 1), we decided to select the
same suppliers. (The only negative we’ve noticed with the EBC ‘blacks’ is that
they shed a fair amount of dust.) The RDA grooved Falcon front discs retail at
AUD$187 a pair while the high performance EBC ‘red’ ceramic fibre pads cost a
substantial $242. At the rear the RDA grooved discs are $143 and the EBC ‘green’
pads come in at $126.50.
The fitting of the brakes was carried out by
Simon’s Car Clinic of Tamborine, Queensland.
Fitting the Front Brakes
The first step was to unbolt the caliper. With the
caliper removed, the stub axle split pin, keeper nut and main nut could all be
removed. The disc/hub assembly could then be removed, revealing the stub axle
and....
...the inner and outer bearings. The tapered roller
bearings showed signs of previous overheating – the colour wasn’t even along the
length of the rollers. Simon suggested they needed replacement, so a front
bearing kit was ordered. This included front seals, which are needed when
fitting the new discs. The front bearing kits cost $45 a pair.
The stub axle itself looked fine – no scoring or
signs of overheating.
The next step was to thoroughly clean the new RDA
discs. They come coated in protective oil and it’s vital that this coating is
completely removed. Simon used a parts washer...
...followed by the spray application of a specific,
fast-evaporating brake cleaner.
The next step was inspect the pins on which the
caliper floats. The piston pushes on only the inner pad and the other pad comes
into contact with the outer surface of the discs as the caliper ‘floats’ across
on its sliding pins. Good braking performance requires that the pins are well
lubricated and in good condition. Note the arrowed shiny parts of the pin where
some wear has occurred.
A special Dow Corning Molykote high temperature
grease was used to lubricate the pins and also the bushes in which they float.
The inner bearing seal was applied next. It was
lubricated with a thin smear of bearing grease....
... before being placed on the inner diameter of the
hub.
It was then inserted with an appropriately sized
drift – in this case, a piece of square cut exhaust tube. Note that RDA suggest
the seal should be pushed fully home, otherwise it may interfere with the
seating of the wheel bearings.
The old seal had torn, perhaps because of
insufficient lubrication. Note the tone wheel for the ABS – when sourcing
replacement front discs, make sure this wheel looks identical in the new
disc!
The new bearings are amongst the best brands
around – Timken. Don’t use no-name bearings...
Proper greasing of the bearings is vital –
incorrect greasing is a probable cause of the wear seen on the previously fitted
bearings. The grease must be forced through the bearing so it appears at the top
gap, as shown here. This is easily achieved by cupping a generous portion of
grease in one hand and rapidly and repeatedly pushing the bearing into it until
the grease is forced right through the bearing.
The inner bearing was then applied to the stub
axle...
...followed by the new disc/hub assembly.
The outer bearing was then inserted....
..followed by the retaining nut.
The nut was torqued to seat the bearings, then
backed off before being re-torqued to the correct value. Note that Simon
normally does this by feel, however in this case he followed the provided
instructions to the letter... only to find that there was still some movement in
the wheel. He then went back to his own trusted technique, which torqued the nut
up perfectly!
The keeper nut and split pin could then be
installed.
The dust cap needed only a thin smear of grease
inside it (the grease traps the dust)...
...before a thin smear of silicone sealant was
applied around its mating flange...
...and it was pushed home.
So that’s a front disc on – now what about the
pads? Not having fitted this type of pad before, Simon carefully read the
instructions, especially with regard to the use of anti-rattle shims, glue or
anti-seize. In this case, none are required!
A G-clamp was used to push the piston back into
the caliper. (Simon made the point that he has the “right” tool for this job but
with these calipers, the G-clamp was absolutely as effective and easy.)
The ceramic pads are heavily chamfered.
The pads could then be clipped into the calipers
(they’re held in place by their springs)...
...and the slides on which the pads move lubricated
with Molykote...
...before the caliper was then bolted back into
place. Simon first placed a smear of Molykote grease on the bolts to protect
them from corrosion.
So that’s the front brakes on – next week we’ll
install the rear discs and pads... and be in for a helluva shock when we find a
huge mechanical failing in the braking system!
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Simon
was paid at normal commercial rates. The discs and pads were supplied at trade
prices.
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