Tech Tips: Maintaining Your Porsche's Brakes
by Bob Schoenherr,
Redwood Region Membership Director
This month, Chris has asked me to provide info on doing a brake job on
your Porsche. First and foremost, it is highly important that you do NOT
attempt this yourself unless you feel confident that you have the
correct directions and mechanical ability to:
- take apart your brakes
- measure the wear of the brake parts
- reassemble your brakes
- test the brakes properly
Remember: SAFETY FIRST. As soon as any brake problem is noticed, get
it repaired immediately. Delaying brake repairs is extremely dangerous.
The longer you delay fixing brake problems, the more you increase the
cost of doing so and, more importantly, you are putting yourself at
risk. If at any time you feel a "spongy" brake pedal or one that gets
lower underfoot you need to look into finding the problem immediately.
There are so many models of Porsches today, from 356 to 991, that it is
best to check forums and repair manuals for a list of tools, part
specifications, and step-by-step directions. At the end of this article
are some DIY (do it yourself) links for your viewing pleasure.
- Brake rotors (discs): Inspect all the way around the surface and
on both sides for any concentric scoring (grooves) or obvious
defects. If defects are found, replace your rotors immediately. Any
rotor discoloration may be a sign of overheating and more damage
than you want to deal with. Take your car to Hi Tec or one of our
other sponsors for professional assistance.
- Brake pads: Generally, rotor scoring matches on the pad. Inspect
for uneven wear, breakage, or cracking on the friction surface. If
defects are found, replace the pads immediately.
- Newer cars have brake pad sensors to warn of pad wear. If you
are replacing your pads, it is a good bet that the sensors should be
- Brake drums on older Porsches should also be inspected on a
regular basis. You need to remove the drum to do so. The drums
should not have excessive grooves or have a deep "trough" dug into
them where the shoes ride.
- Brake shoes on older Porsches should be worn evenly and have no
rivets protruding to the friction surface.
- Check calipers, wheel cylinders, hoses, and fittings for any
hydraulic fluid leakage. Inspect the master cylinder, reservoir, and
proportioning valve assemblies as well.
Use your ears every day to listen for the following:
- Know how your brakes should sound and listen for abnormal noises
when driving the car. Find a high wall or drive between buildings
with your windows down. This makes picking up the sounds easier.
- Beware of squeaking, which may be caused by dust or dirt on the
brakes, loose pads vibrating when applied, or worn pads.
- A rhythmic noise or pulsating noise might mean you have a warped
rotor. In extreme cases, warped rotors cause the brake pedal also
to pulsate underfoot. Don't confuse this with ABS feel.
- Any constant brake noise means stop the car and start looking
for the problem.
Once a year you should check:
- "Run-out" - this is measured by placing a gauge on the part, and
rotating the part 360 degrees. The total variation is recorded as
- Wheel bearing play
Recommendations to follow:
- Keep the hydraulic reservoir at the proper level with the fluid
type recommended by Porsche. Never substitute or mix types of fluid.
Never use old hydraulic fluid. Always use a fresh container.
- Keep brakes clean by washing them off at the same time as your
car. This keeps squeaky dust and dirt off the pads and makes brakes
easier to inspect and work on.
- Never spray, touch or drip any oil or lubricants on the brake
friction surfaces. If this occurs, clean it off IMMEDIATELY.
- Know your brake system - how it should work, feel and sound -
before it acts up, so you'll know when something's wrong.
- Check rotors for correct thickness. Replace the rotor at the
same time as the pads if it is out of spec.
- Keep a repair log with receipts when any service is performed on
your Porsche. Too many benefits of this to list!!!!
- After installing new pads, remember to "set" them properly. This
conditions them for maximum performance and prevents premature
failure. Instructions for setting pads is usually provided in the
package with your new pads.
If shopping for Porsche brake parts, remember two important things:
- OEM/OES (original equipment manufactured/supplied) or equivalent
pads and rotors are not always cheap. You do, however, get what you
pay for. OE parts will give you the most trouble-free driving and
peace of mind. And...isn't that what's most important?
- Before requesting any brake parts for your Porsche, make sure
you have the year, exact model designation, engine size and type,
brake configuration, type of rotors (solid or vented), vehicle ID
number (VIN) and production date.
As for replacing your brakes, most cars today use disc brakes, so
lets give you the basic steps assuming all braking components are in
- Jack up your car and place the car on jack stands, then remove
- If you are going to replace the rotor, loosen the rotor holding
screws Some cars have them and others do not.
- Remove the brake pad pin or pins.
- Remove the brake pads.
- Compress the caliper pistons.
- Insert new pads.
- Reinstall pad pins.
- Before driving the car, PUMP UP YOUR BRAKES. The pedal will feel
spongy because you depressed the caliper pistons.
- Now break in the brake pads by driving about ten miles or so. Do
easy stops at first, and then some stronger stops. Check the
recommendations of the brake pad manufacturer for correct break-in.