Last week in
New Brakes for the Falcon,
Part 1 we showed the fitting of high performance RDA front discs and EBC ‘red’
ceramic front pads. That process went smoothly but we were in for a shock with
the rear brakes! But before getting to that, let’s install the new rear discs
and pads.
Again the job was performed by Simon’s Car Clinic
of Tamborine, Queensland.
Fitting the Rear Brakes
Simon firstly unbolted and put to one side the
rear caliper (with its brake hose still connected) before...
...unscrewing the single screw that holds the disc
captive on the hub.
The disc could then be pulled off. At this stage
the handbrake internal drum brake shoes could be inspected – they were fine.
Specialised fast evaporating brake cleaner was
then sprayed over the assembly.
Simon then scraped the front face of the hub
clean. This was an important step because any corrosion or dirt build-up will
cause the new disc to have run-out. That is, the disc won’t sit at right-angles
to the axle.
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 brake cleaner.
The new discs could then be placed on the hub.
The sliding caliper pins were lubricated with high
temperature Molykote grease...
...as were the parts of the new EBC ‘green’ pads
which slide on the caliper shoulders.
The EBC ‘greens’ come with a break-in coating on
the face of the pads.
The pads were then clipped into place and the
caliper pins inserted. The caliper could then be bolted into place.
The Problem!
With the front and rear brakes fitted, the next
step was to change the brake fluid. Simon started by sucking out the original
brake fluid...
... and adding fresh fluid.
But he soon ran into a major snag. No matter how
hard the brake pedal was pushed, the fluid refused to flow out of the 'cracked'
rear caliper bleed nipples. Incredibly, the rear brakes were not working!
By 'cracking' various brake line junctions Simon was
able to trace the non-flow of fluid back through the plumbing to the ABS unit,
and then from there right back to the master cylinder. There was no fluid
pressure coming out of the master cylinder for the rear brakes – a new master
cylinder was needed.
However, one of the advantages of the Falcon is
its incredibly cheap parts prices, so just $150 later, a brand new master
cylinder had arrived.
The new master cylinder was quickly and easily
installed. Simon then bled the master cylinder, followed by the rear brakes and
then the front brakes. New fluid was added to the reservoir during this process
and the brakes bled until new, clean fluid flowed from the bleed nipples. In
this way the fluid was replaced.
But
how could I have been driving the car and not been aware that the rear brakes
were not working? Thinking back, there was only one situation where it was
clear: that was, reversing slowly down my steep driveway. In this situation, the
brakes seemed to lock-up (and then ABS) very easily – I now realise that was
because the weight transfer to the rear caused the front wheels to be unloaded...
and they were the only ones doing the braking.
In
fact, I think it very likely that the rear brakes were not very effective even
when the previous owner was in possession of the car. That would explain why the
receipts he provided when I bought the car showed it had undergone many front
disc replacements and machinings, and why the front discs were warped.
One
easy way to see if the brakes are all working is to brake hard a few times and
then feel the temperature of the wheels. Especially if they’re alloy, they will
be warm to touch.
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The Results
So what does the Falcon brake like now? Obviously,
there’s no point in comparing ‘before’ and ‘after’ configurations – not when the
front discs were warped and the rear brakes weren’t working!
However, compared with generic big car brakes, the
Falcon’s brakes are now very good. Interestingly, despite the high performance
pads, the brake pedal is light and has excellent feel. In fact, despite most
Falcons and Commodores having very good linearity and feel in their brakes, I’d
suggest that the EBC pads and RDA discs give the Falcon better than standard
brake pedal feel. That’s saying something, because most hi-po brake pads
(especially when cold) need a good solid push to get things working.
Clearly with ABS and the same tyres, the maximum
retardation is unchanged – you can’t get greater deceleration than ABS’ing! But
you can now brake right up to that point with precision and control. The only
downer is that I think the brake pedal travel is a bit long, but Simon suggested
that it was nothing to be concerned about, implying that it is typical of the
Falcon.
With a retail cost of about $700 for the discs and
pads, and a labour and parts bill from Simon of $447 (including the new master
cylinder, front wheel bearings and seals), the exercise was not a cheap one. But
the brakes now have more than enough capability to hold up under hard driving,
even with potentially a fair amount more power available.
Simon
was paid at normal commercial rates. The discs and pads were supplied at trade
prices.
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