The fluid in the car's braking system runs from the
brakes themselves mainly via rigid metal pipes. But there needs to be some
flexibility in the system to allow the wheels to move in relation to the car
body, whether for the purposes of steering or suspension. This is provided by
Front and rear
At the front of the car, these
run between the pipes and the brakes.
The same arrangement is used at the rear if the car has independent rear
suspension. But if it has a
, there is usually just one hose situated
in the centre of the
, linking the pipe from the master
pipes leading to the rear brakes.
If you suspect that you have a leak in the braking system, one possible
source is the hoses, which should be checked straight away.
If you are inspecting the front hoses, turn the road wheel on to full lock
to give yourself a better view. For the rear hoses, you may find you need to
use an inspection lamp to see them.
Inspect the whole surface of the hose, looking for cracks and chafed or worn
patches. Ask a friend to press the brake pedal while you feel the hose to see
if it expands.
If one of the hoses fails any of these tests, you need to replace it. At the
same time it is safer to replace all the hoses because they will all probably
be the same age.
Three types of hose/brake connection
If the hose is connected to the brake via a banjo connection, loosen the hollow bolt with a spanner.
The hose may screw straight into the brake
, in which case use a
spanner to unscrew it.
Or the hose may be connected to the brake by the same sort of union as
that found linking a hose to a pipe. Undo this connection using two
spanners, one for each union.
The way in which the hoses are plumbed into the rest of the braking system
depends on what they are attached to.
If the hose joins a pipe, it will be secured to the bodywork by a bracket so that the hose cannot get damaged by flexing with the car's movements. The end of the hose has a metal union on it that passes through the bracket and is held by a nut on the other side. The hose joins to the pipe via a male and female union - the male formed by the hose and the female by the pipe.
Where the hose runs into the brake assembly, there are three possible
designs of connection. One is a banjo connection, in which the end of the hose
consists of a metal ring. The ring is fixed to the assembly by a hollow bolt -
hollow so that it will still allow fluid through to the brake.
The two other alternatives are that the hose screws straight into the
caliper, or that it is attached to the brake assembly by a union similar to
that between the hose and the brake pipe.
Before you start removing hoses,
a plastic bag between the top of the
and its cap to minimize the loss of brake fluid. Also
have a roll of cling film and some rubber
at hand to cover up any holes
that become exposed when you remove the hose.
Removing a hose
To undo a hose or pipe union, fit an open-ended spanner (or, better still, a
split-ring spanner) to the female union. Fit another spanner to the nut-shaped
section on the end of the brake hose union to hold it steady. Use the
open-ended or split-ring spanner to undo the pipe union. Move the pipe out of
the way, then undo the nut on the end of the hose and slide the hose out of the
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Checking the condition of your car's brake pipes is a job that is all too
easy to forget because the pipes are mostly hidden underneath the car. However,
these pipes can deteriorate to the point where they start to leak, causing a
dangerous loss of
and eventually partial or even complete failure
of the braking system.
As well as being a legal requirement, it is also an essential safety measure that your brake lights work correctly. Any faults in the brake lights are usually easily traced. The
itself is a simple one, controlled by a
operated either directly by the brake pedal or hydraulically by the increase in
in the brake pipes.
One of the most unnerving things that can happen in motoring is that you
brake and one or more of the wheels locks up. This has two possible effects. It
can make the car slew to one side or, if the car happens to skid in a straight
line, the steering becomes useless and you lose all directional control.