Brake System: Routine Service
Doug Dwyer
Brake pads should be inspected every 6000 miles or any time the wheels
are off for rotation or other servicing and should be replaced if 1/8"
or less of lining material is left. Front pads are easy to inspect with
the wheels off but rear pads, due to the inboard brake location, can be
easily inspected only if the car is elevated. Inspection should also
include checking the condition of caliper piston seals and flexible
brake hoses. You'll want to check for splits, cracking, or any sign of
deterioration. Any sign of fluid leakage is cause for immediate remedial
action.
When checking rear brakes is it important to check for leakage of the
rear axle seals. If they are leaking badly gear oil from the
differential will be slung onto the brakes. If the seals are leaking
just slightly, their replacement (big job !) can be postponed by
religious cleaning of the area with aerosol brake cleaner on a regular
basis to keep the leakage from migrating onto the brakes.
Brake fluid level in the master cylinder should be checked anytime you
have the bonnett lifted for servicing, but not less than once a month.
You'll want to check for external fluid leaks and overall appearance and
condition. It is normal to add fluid from time-to-time as the brake pads
wear down....as the pads wear the caliper pistons move outward and
create more space for fluid to occupy.
The brake fluid should be completely flushed thru and replaced by fresh
fluid every 18 months, according to the Jaguar service manual. This
important service is often overlooked. Old, dirty fluid boils at a lower
temperature and can be the cause of brake fade and/or soft brake pedal
feel.
The brake fluid of choice among most Jag owners is Castrol GT/LMA. Ask
your local parts supply to get some for you if they don't carry
it....most do, however. Some Jag owners prefer synthetic brake fluid.
See the archives for hours of discussion on the subject. Generally
speaking the synthetic fluid works very well providing all traces of
regular fluid have been removed from the system.
Brake hoses should be replaced at the first sign of deterioration or
every 10 years.
Brake rotors require no regular service but will often warp due to age
and heat, giving a pulsating feel to the brake pedal. New rotors are
readily available and inexpensive so, considering the labor involved, it
usually makes sense to replace them rather than having them resurfaced.
The vacuum hose and piping to the power brake servo should be checked
for cracking, softeness, or general deterioration at every oil change.
The best maintenence for your parking brake is to use it daily. Lack of
use will make the calipers seize up and render the parking brakes
inoperative. The small pads for the parking brakes almost never need
replacement.
If the brake pads need replacing you'll be amazed at the variety of pads
to select from. See the archives for discussion but it is generally
accepted that OEM pads or equivalent are prefered. High performance pads
and/or pads with a very high metallic contact require higher pedal
pressure and accelerate rotor wear.