While checking my VT recently I noticed that the
left front air duct to the disk brake had a brake in it. This duct
takes air from the front of the car and redirects it over the front disk
brake rotors. This helps to insure that the rotors keep cool when braking at
high speeds. Because the front wheels move so much relative to the rest of
the car, part of the duct work consists of a flexible hose. This hose
is almost 3 inches in diameter. It is made of a flexible material that also
contains a spiral metal spring like support. Over time it appears the
flexible material fatigues and shows brakes. This allows the air to escape
leading to less cooling of the brake rotors.
To begin with one should examine these ducts
every few months. I usually do it with each oil check. Look for a split in
the plastic material. A typical example of this is seen in figure 1 below.
Note the hole close to where the duct is attached to the rotor. The
good news is that because the ducts have a steel spring wound into them they
can be is a real sorry shape before they will disintegrate and catch in the
wheel. Nevertheless if there is any hole in a duct cooling to the
brake rotor will be severely compromised. Fortunately replacement is simple
and well worth the effort.
The first thing to do is raise the car and
remove the wheel and ground panel under the front of the car. This will
allow you to remove the old duct from the metal tube that brings air in from
the front of the car (see figures 2 and 3). Figure 4 shows the new
duct tubing. I picked this up at a local auto racing store. The tubing I got
was 3'' in diameter. A better fit would be about 2 and 3/4'' diameter
material. I had to wrap some tape around the rotor duct metal to get a snug
fit of this duct over it. The duct is held in place wit two large hose
clamps as shown in figure 5. Likewise it is held in place on the front end
with one large hose clamp as shown in figure 6. The only tricky part
is putting in the hose clamp that attaches the duct to the frame of the car
and stops it from sagging. This is shown in figure 7. It is very important
to leave enough stretch and compression room for the duct so that the wheel
can be turned full left and right without straining the duct. An example of
this is seen in figure 8
Be sure you test drive the car after this
repair.
|