Piston Kirk is back!
Today we will see how to replace the brake pads
on a Boxster 986.
The first step is to lift the car with a jack to remove the wheel.
The point of support of the jack is here.
Position it underneath, then lift the car.
The rear wheels can be blocked by the handbrake.
It is therefore very easy to loosen the bolts when it is in the air
but the front wheels are not blocked
therefore, the wheel turns when you try to loosen the bolts.
To avoid this problem,
before lifting the car with the jack,
you have to loosen the bolts very slightly,
take a full turn to unlock the bolt
The antitheft nut is located in the front trunk,
at the spare wheel, in the tool bag.
Now that we have the antitheft nut,
we will be able to slightly loosen the five bolts
then we lift the car with a jack
until the wheel stops touching the ground.
unscrew the 5 bolts completely
Then remove the wheel.
Do not forget to put the wheel under the car to secure
in case the jack piston gives way.
Now that the view is clear,
we will be able to inspect the state of brake pads.
Normally, wear must be checked every 15,000 kilometers.
It must be at least 2.5 mm thick.
It is necessary to measure the thickness between these two points.
If you go below this limit of 2.5 mm,
the disc will start to wear the warning contact wire of the brake pads wear indicator
and you will then have an alert that will appear on your dashboard.
To solve this problem, it's very simple,
you have to replace all the cable which costs 9 euros.
When replacing the cable, the red light goes out automatically.
Before replacing the pads,
we will also measure the state of wear of the disc.
For that we have to measure the gap here.
On a 2.5L and a 2.7L Boxster the disc thickness must be at a minimum
22 mm in front and 18 mm behind.
For 3.2L you must have 26 mm in front and 22 mm behind.
As the disc is still good,
we can limit ourselves to the replacement of the brake pads.
To remove the pads,
we will start by removing this clip with a pliers.
Now that the holding rod is no longer held by the clip,
we'll be able to remove it by gently tapping on it
using a hammer and a screwdriver.
Once the rod is removed,
it will be necessary to remove the cable of the wear indicator which interferes with the extraction of the spring.
Remove the end of the cable of the wear indicator
pressing each side with a small flat screwdriver,
then, remove the cable from the spring.
Once it's done,
nothing holds the spring back, you can remove it.
As the new pads can measure up to 9 mm more than the ones we will remove,
we will have to make room to insert them.
So, before removing the old pads,
We will first spread them to stick them as much as possible against the walls of the brake caliper,
thus, we will free up space for the news ones.
Normally professionals use a special tool to spread the inserts,
but to limit costs, I'm going to use a pliers,
taking care to put fabric on the brake caliper to protect the paint.
Of course, the pliers is less convenient than the specific tool,
because not only must I proceed in two stages, first pressing the first pad and then the second
but also because you have to use some strength.
The other problem,
it is that when you tighten the second pad, the first tends to return to its place.
It is therefore necessary to hold with the hand the first pad
while squeezing the second.
To make things easier,
you can open the brake fluid reservoir cap
to have less pressure.
Do not forget to close it at the end.
For those who do not want to use their muscles with the pliers,
there is another alternative:
Two clamps can be used with a rubber tip.
The advantage is that when you press the second pad,
the first pad remains in place.
Now each pad has been repelled and can be removed.
Once the pad is out,
it is easier to unclip the head of the wear indicator.
If the head is damaged or broken,
you will have to replace all the cable.
To remove the old cable,
you will have to go to the plug that is here.
Before, unclip the cable that is attached in two places.
The first clip that is near the pads
then remove the cable from the second clip behind it.
We can now unplug the plug,
starting by unclipping the metal latch.
As it is no longer locked, just pull the plug
then replace the new cable.
Do not forget to lock again
and put back the two clips located behind.
Before inserting the new pads,
we'll have a look on it.
Depending on the model, the pack of four pads will cost you between 90 and 110 euros
In theory on a 2.5L and a 2.7L
the pads are supposed to be 11 mm thick in front and behind
while on a 3.2L
it is 12 mm thick in front and 10.5 mm behind.
Yet on my new pads,
I have 1 mm less in front and 0.5 mm behind.
This less thickness is not trivial,
this represents a reduced service life of 10.5% at the front
and 6.25% at the back.
But I must not see see evil everywhere,
this does not necessarily come from a desire of the manufacturer to harm his client,
this may possibly come from a manufacturing tolerance
or a desire to facilitate the passage of pads during replacement.
But I do not exclude that it is perhaps a way like any other to increase its profits.
Let's close this parenthesis on the thickness of pads.
Before installing new pads, make sure you have the right ones.
We will compare the old with the news.
As can be seen, everything is in order, they are identical.
Before putting them in the caliper it will be necessary to prepare them.
You can spray grease anti-squeak
on the surface that is in contact with the pistons
to limit noise and wear.
Or you can alos use tube grease,
and spread it on the surface with the finger.
The spray cost about 12 euros
and the tube 17 euros.
Be careful, do not use any grease.
It is necessary to use special brake greases
able to withstand high temperatures above 1000 ° C (1832 ° F)
For example, the grease I used can withstand up to 1400 ° C (2552 ° F)
This also prevents the parts from welding together in case of overheating.
Be very careful to put this grease on the metal surface and not on the friction surface.
Otherwise, it will be very difficult to stop your car.
We will also put some grease on the lateral support points of the pads
Be careful not to overflow the friction zone.
Now we can slide the pads in their place,
one after the other.
Then we put back the spring.
Then pass the cable into the notch of the brake caliper
clip the first wear indicator head into the first brake pad.
Clip the cable in the spring,
then insert the second wear indicator head into the second brake pad.
Now put back the support rod.
Be careful to put the hole up so you can insert the locking clip.
Push the rod to the stop,
then insert the locking clip.
It's not quite finished yet,
before changing the pads of another wheel,
you have to put pressure on the brake caliper pistons first
to push the brake pads against the disc.
Enter inside the car
and press the brake pedal several times
until you get resistance.
this operation must be done between each pads change
because if you push the pads of the 4 wheels at the same time
without returning the pistons to their original position each time,
the brake fluid of the pistons will go up in the tank
which may overflow it.
Since we have access to the brake disc,
we will take the opportunity to remove the dust that has accumulated in the holes
which will improve the cooling.
This cleanup operation is only for the Boxster 3.2L
because if you have a 2.5L or a 2.7L
your brake discs are not perforated
Now you put the wheel back by tightening the bolts crosswise
once a bolt is put, it is necessary to put the next one in a diametrically opposite way.
For example, we put the first here,
the following there,
the third here,
the fourth there
and the last here.
Start by screwing the first turns by hand
to be sure not to distort the thread.
Theoretically you do not have to force.
Then screw it gently until it forces.
Once the five bolts are tightened without forcing too much,
use a torque wrench,
set the tightening torque to 130 N · m
then squeeze the first until you hear a clicking sound that tells you it's good.
Then tighten the one that is diametrically opposite
and so on until the 5 bolts are tightened.
As the antitheft nut is more fragile than normal nuts,
You can tighten it to only 110 Nm
to avoid breaking it when loosening.
If you are on the rear wheels, the wheels are blocked by the handbrake,
so you can squeeze when the car is still on the jack.
If you are on the front wheels,
after having lightly tightened, it will be necessary to lower the jack a little bit
until the tirecome into contact with the ground with enough pressure
to block the rotation of the wheel.
Then tighten the 5 bolts to 130 N · m
then lower the jack and remove it.
Here, the first wheel is finished, it remains only to reproduce the same operation again three times.
Before you start, you need to know some things:
it may seem obvious to many of you who are used to repair your car
but I know from experience that part of my audience is composed of neophytes,
it is therefore good to explain some basics.
The first is that you should never replace the pads of a single wheel,
otherwise braking will not be uniform.
The pads must be replaced in pairs of wheels:
the two front, the two behind or the four brake caliper at the same time.
The second point to know,
it's that your brake pads will have their best coefficient of friction
than about 250 km (150 miles).
During this time it is better to avoid emergency braking
as far as possible.
Now it's time to take a ride on the road.
But before, we'll check that the pedal brake reacts correctly.
Once you have pumped with your foot until you have resistance,
turn on the engine.
Normally, the Brake Assist must engage
and the brake pedal should go a little deeper.
Now we can take a ride to make sure the car brakes properly.
Before concluding, I would like to explain one last point:
Keep in mind that it is not just the brake pads or the disc to be replaced,
the brake fluid is also damaged with time,
it can absorb moisture and then becomes less efficient.
In theory, it should be replaced every two years.
If you do not have the "Traction Control" option or the "PSM" option
The replacement of the brake fluid is an operation that you can do yourself.
Attention, the brakes must be purged in a certain order:
rear right
then left back
and then right front
then left front.
if you do not follow this order
you may have problems with the ABS of the car.
If you have the "Traction Control" option or the "PSM" option
that is to say one of these two switches on the dashboard,
Warning !
To purge the brake system,
it is imperative to use a Porsche diagnostic case
to activate the purge procedure and open the valves.
It is better not to do this operation yourself.
It is better to entrust this work to your Porsche dealer
to avoid ending up with a faulty braking.
Here ! Now you can change yourself your brake pads
for a price ranging from 112 to 130 euros.
But keep in mind that even though the procedure is simple
it does not tolerate the least oblivion,
because unlike the previous tutorials I made,
this time, it's your safety that depends on it.
So be very meticulous and get started!
See you next time!
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