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Old 07-17-2012, 11:32 PM   #107
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Join Date: Oct 2006
Posts: 33,142
Recent update!

I did a brake pad change on a 2003 Porsche Carrera. OMG the brakes are so nice to deal with in comparison to an E46. Where to start...

-Calipers are super light, way lighter than even little 323 calipers.
-Only 2 easy to access bolts to take the entire caliper off, a third little M6 hex cap crew that holds the brake line on the fronts.
-The pad wear sensors monitor pad life on all 8 pads of the car, versus the two monitored pads on the E46, and the sensors cost the same. There are 4 sensors instead of 2, so $40 for a full set, instead of $20, but easily worth it for the extra information to most people.
-The pad wear sensors are identical for all four hubs, so one sensor can be a spare for an every caliper. The neat way Porsche does it better than BMW is instead of putting that little box with the connections for the wheel speed and pad wear inside the wheel well, or under the side skirt for the rears, Porsche puts that little box right on the spindle. Simple. That way all pad wear sensors only need a very short length of wire, there are less loose wires in the wheel well, and only 3 plastic clips to hold the wires down, versus like the dozen used for one rear pad sensor on the E46.
-No anti-squeal paste needed! Porsche Brembos use these nifty little vibration damping pads with a self adhesive backing. Kinda pricey little things, but can be reused if not damaged. Also the pads themselves had little rigid pendulum-like weights on them which I assume are also to prevent squealing and vibrations.
-If you don't care about squealing, you can take the vibration damping pads out, and then you can change brake pads without even taking the calipers off. Without the vibration damping pads, you can literally just take off the front wheel, pop out one pin with a screwdriver or needle nose pliers, and the rest of the procedure only involves your hands.

Aside from the initial cost, Porsche Brembos make excellent brakes for a performance street car or light duty track car. Actually, they would probably do excellent for most track cars just because of their large size, low weight, and easy serviceability.

Now for some more pictures, which everybody loves. Sadly, I was too lazy to get out the DSLR, so iPhone 4 pictures.

Rear pads with vibration damping shims removed, normally held on with just a little glue. The little "spiders" are different for leading and trailing pistons, because a smaller leading piston and larger trailing piston.

The old pads had some life still, but definitely getting close to the end.

The trick is to break the torque on the lug bolts BEFORE you lift the car. So much easier.

Carreras only have the corner mounted jacking points and no central jacking points. The corner jacking points are a stamped round sheet metal puck, versus the rectangular plastic pads of an E46. Also, the weight is so far in the rear of the car and the suspension so stiff, that by lifting the at the rear jacking point, lifts the entire side of the car, lol.

Taking all the wheel bolts out. Porsche also use these cool wheel bolts with thick rounded captive washers. I'm not quite sure why, but interesting. The bolts didn't seem to break loose as suddenly, but slowly released torque on removal. Wheel torque is 130Nm, almost the same as the 120Nm of an E46.

The little reusable spring pin that holds the brake pad retaining pin in place. Very simple, reliable, strong, easy to work with design.

Push down the spring clip to relieve pressure on the pad retaining pin. Only thumb pressure is required.

With pressure on the spring clip, the pad retaining pin slides right out.

The simple pad retaining setup. Don't lose the small spring pin clip thingy.

Undo the two clips holding down the pad wear sensor wire.

Instead of the fragile plastic connector box in the front wheel well, the 996 uses a springy metal clip, that requires just a flat head screwdriver to unlock the connector.

Pull the connector out:

Make sure to undo the little 10mm hex cap bolt holding the brake line. If you forget to take this off, and pull the caliper, you will bend the hard line connected to the caliper.

Unbolt the two big bolts holding the caliper on. T55 torx for the front, a big socket cap like 10mm in the rear. 80Nm torque.

Caliper off! Spread dem cheeks/pads with preferably a pad spreading tool, or in my case I only had a wooden handle of a mallet. Takes a bit of force to compress the pistons all the way back into the caliper.

Pads just pop right out after that.

New front pad shims with adhesive backing. Not so easy to reuse the old shims on the fronts.

Put the new shims into the calipers and remove the adhesive protecting film.

Drop in new pads, reassemble.

All done! Notice the little suspended weights attached to the brake pads.

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