TRW Aftermarket offer step-by-step instructions for this common workshop task.
Whether or not a brake hose is worn or damaged, TRW recommends that hoses should be changed every 50,000 km or after five years, at the latest. This is because the rubber from which these hoses are made is a perishable item and has a defined lifetime.
How to change one
Check that the supplied hose is the correct one and read any fitting instructions supplied. Now disconnect the brake hose from the static fixed brake pipe (see below) and cap the fixed brake pipe to prevent excess fluid loss.
Then remove the hose from the caliper (see below).
With the new brake hose, place the end into the caliper first (see below), making sure you don’t over-tighten.
Feed through any mounting brackets and reconnect to the fixed brake pipe (see below), again ensuring that you don’t over-tighten.
Clean off all connection areas to ensure no brake fluid remains as this is highly corrosive. All TRW brake hoses have a marker line along the length of the hose (see below)
It’s essential that this marker doesn’t appear to be twisted as this would suggest the hose is under stress and incorrectly fitted. Now proceed to bleed the brake system in accordance with the VM’s instructions (see below).
Once bleeding is complete, replace the reservoir cap.
Braking performance
With age, brake hose material loses its strength and this can lead to volumetric expansion – in other words, a bulge in the wall of the brake hose which can affect the braking performance. The low volumetric expansion rate of TRW OE quality brake hoses gives superior pedal feel and better stopping times.
