Expected life of emergency brake shoes? Advice on a DIY four wheel brake job?

Since I got my 2000 base two and a half years ago at 67K miles I've pretty much just been lurking; nothing like the old days when I was on every day, first thing in the morning on PPBB, deputized to catch the early spammers...but that's another story.

My car is approaching 90K miles. The brake wear indicator light is on intermittently. Both front and rear pads look like they are at about 2/32-3/32", MOL.This is my daily driver and I don't want to be without it long, that is, I want/need to do this in one day. So I'm wondering about what parts to order.

What looks like complete service records only show front pads and rotors changed at the dealer at 45K miles, and nothing else done to the brakes. Is that believable? If the rule of thumb is that the rotors are good for two sets of pads, I'm hoping I won't have to do rotors too, but I guess I should pull wheels and measure them before placing a parts order. But once I've got everything apart, what about the emergency brake pads - any ideas about expected life?

Other suggestions ? Pad brands for a non-tracked daily driver?

Thanks

Tom F.

is 30k for front pads, 60k for rear pads. Rotors last about twice as long as pads. Measure the rotors if you're not sure.

Parking brake pads only wear if you drive with them on (or if they get stuck, which does happen). Generally you can tighten the parking brake cable a few times before you have to replace the pads. The adjustment is under the center arm rest. You don't have to remove the console to get at it.

I would measure the rotor thickness and visually inspect the brake pads. Then you'l know exactly what to get.

... just run your finger around the edge of the rotor.
When they start to wear a lip will develop.
When the lip measures 1 mm this means that the rotor has worn 2 mm (the back side wears like the front) and it's time to replace the rotor.
I generally see much more mileage on pads and rotors as Boxsterra sees.
Many of my customers get 40-60,000 miles on the front pads, twice as much on the rears, but it all depends on how aggressively you drive.
Happy Boxstering,
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

Never

Quote
Tom F.
Since I got my 2000 base two and a half years ago at 67K miles I've pretty much just been lurking; nothing like the old days when I was on every day, first thing in the morning on PPBB, deputized to catch the early spammers...but that's another story.

My car is approaching 90K miles. The brake wear indicator light is on intermittently. Both front and rear pads look like they are at about 2/32-3/32", MOL.This is my daily driver and I don't want to be without it long, that is, I want/need to do this in one day. So I'm wondering about what parts to order.

What looks like complete service records only show front pads and rotors changed at the dealer at 45K miles, and nothing else done to the brakes. Is that believable? If the rule of thumb is that the rotors are good for two sets of pads, I'm hoping I won't have to do rotors too, but I guess I should pull wheels and measure them before placing a parts order. But once I've got everything apart, what about the emergency brake pads - any ideas about expected life?

Other suggestions ? Pad brands for a non-tracked daily driver?

Thanks

Tom F.

brake with the car moving at a walking speed to either dry the things or scrape off rust if the car has sat for a long period (1 to 3 weeks) unused. The cabling has been adjusted at least once. Oh, the car with its original parking brake pads/shoes now have been in service for over 259K miles.

When the brake wear light comes on I replace whichever axles' pad are causing the light to come on. A quick check of the brake pad thickness will tell you which pads need changing. Generally this is the front pads.

Believe it or not brake life is so good I can't even remember the last time I did the brakes and how many miles ago. The current set of brakes (OE rotors/pads) appear to have very little wear. For my money OE pads/rotors can't be beat.

When time though, I replace pads, and all the hardware. I buy a brake hardware kit which contains all new hardware except the pads/rotors to do one axle. Porsche has a part number for this kit but I can't recall it. The kit does not contain wear sensors either. I buy those separately though I sometimes reuse the old wear sensors. It depends upon their condition. If really brittle I replace.

I have two scissors jacks and lift both wheels off the ground after first loosening the lug bolts. I leave one side alone in case I need it for a reference, then once I'm satisfied the 1st side is done and done right I do the other side.

Before you pry apart the brake pads from the rotors siphon out some brake fluid from the brake fluid reservoir so when you push the pistons back in the calipers this doesn't cause brake fluid to overflow out of the brake fluid reservoir.

Have on hand fresh brake fluid to top up the level if it needs it after the brake job.

After I remove the wheel but before I unbolt/remove any brake hardware, I clean the area with a can of aerosol brake cleaner, letting the dirty (black) fluid drip onto several sheets of newspaper. You can even use a brush to scrub as you spray to remove as much as the brake dirt as possible. Be careful about the pad piston dust boots.

I do not use any anti-seize or other chemicals on the brake caliper bolts. I do dab a tiny amount of anti-seize on the threads of the counter sunk flat head screws that are used to hold the brake rotor in place when the wheel is removed. I do not tighten these screws down very much. Just enough there is no play when I wiggle the brake hub/rotor.

Be sure to double check your work and afterwards do a brake bedding in to bed the pads/rotors. This is necessary even if you replace just the pads.

Be sure too to do a brake fluid flush/bleed every two years.

Sincerely,

MarcW.

... seem to last forever.
I'm at 223,000 miles, still on the original pads which don't show much wear.
Happy Boxstering
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

When I bought the car the original owner said it was used "carefully", so I guess it is likely the rears pads and rotors are original. Marc, parked in the driveway, visually the front and rear pads are equally worn, maybe with an actual measurement I can figure out which set of wear sensors need to be replaced; thanks for reminding me about a brake flush and replacing all the relevant parts.

Pedro, I saw your tip about the rotor edges on your site, and went out there with a dime, which happens to be a millimeter thick. From that I'm guessing all four need to be replaced. In the next couple of days I'll free up the garage and pull the wheels to make actual measurements before ordering the parts.

I've only done oil changes on the car at this point, so I'm looking forward to getting more involved in its maintenance. I guess I owe it a 90K service at this point too; even more work to be done. Thanks again

Quote
Tom F.
When I bought the car the original owner said it was used "carefully", so I guess it is likely the rears pads and rotors are original. Marc, parked in the driveway, visually the front and rear pads are equally worn, maybe with an actual measurement I can figure out which set of wear sensors need to be replaced; thanks for reminding me about a brake flush and replacing all the relevant parts.

Pedro, I saw your tip about the rotor edges on your site, and went out there with a dime, which happens to be a millimeter thick. From that I'm guessing all four need to be replaced. In the next couple of days I'll free up the garage and pull the wheels to make actual measurements before ordering the parts.

I've only done oil changes on the car at this point, so I'm looking forward to getting more involved in its maintenance. I guess I owe it a 90K service at this point too; even more work to be done. Thanks again

although this may not be always true for the rear brakes can run hotter and thus wear faster. The rears can run hotter if the car has been driven a lot and hard with the rear brake scoops missing. Those are the two little rubber 'scoops' that hang down just about at the front of the engine. I see quite a few Boxsters running around with one or both missing.

Not only do you have to check front and rear pad wear but pad wear from side to side. It has been my experience with my Boxster that one side (I forget which side now) wore quite a bit more than the other side. I've never seen this before with my Boxster and I've not seen it again. I sort of suspect it was due to my failure to thoroughly clean the brakes before disassembly. This left a dust boot very dirty which affected the piston's natural tendency to slightly retract and pull the pad away from the rotor.

Also, even the pads of the same wheel may not wear the same.

And last but not least a pad may not always wear evenly across its surface. The wear can be uneven enough to form a considerable taper to the pad's friction material. It can be so unevenly worn that at one side the backing plate is near to touching the rotor while the opposite side shows plenty of pad material left.

Unless you are willing to get down and dirty with your car with your car on a lift you almost have to remove each wheel and carefully inspect all pads, inside and outside, and all edges -- top, bottom, front and back -- for any uneven wear that can render the pad subject to replacement. At the same time you inspect the brake lines, any air scoops, and just look for any signs of anything amiss.

If the rotors have a 1mm lip you do not need to measure the thickness. (Besides unless you 'invest' in a rotor micrometer that allows you to measure the entire surface area of the rotor (from the outside diameter to the inside diameter) you'll likely not get an accurate measurement of the rotor's thickness at all points. Rotors too can wear more at the outer diameter or inner diameter too.)

Anyhow, with a 1mm lip the rotors are worn enough to justify replacement. Be sure to always replace rotors at least in pairs. If you replace the front rotor on one side, the rotor at the other front wheel needs to be replaced too. Obviously, if there's a large difference in left side to right side wear the cause of this needs to be determined and addressed.

Sincerely,

MarcW.