# Help! Boxster brakes on my 20th



## aFOURstance (Jan 31, 2011)

So I recently installed my porsche calipers and there are two issues that I'm faced with:
1) the new brake pads are too thick and don't fit with the brand new rotors
2) the two large pins that support the pad and prevent it from sliding forward keep sliding out; hitting the wheel spokes because the dowels are missing. Couldn't find the right size at Advance Auto or Home Depot.. 

Need to come up with a solution quick. Brakes still work and are fully functional, I'm just using stock pads that came with the calipers and there is hardly any friction between the rotors and pads. (Imagine two glass pieces sliding on top of each other)

Thanks in advance for any advice/input. 

Mike.


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## aFOURstance (Jan 31, 2011)

The calipers are from a 2003 Porsche Boxster and the new pads are EBC red dp31207c rotors are Zimmerman also brand new. The only reason I believe the oem pads fit is because they are used pads that were originally off the Porsche. I'm sure there are enough people that have done this oem plus upgrade please chime in and share your thoughts


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## aFOURstance (Jan 31, 2011)

bump. I'm sure it's not as complicated it seems, just need some clues/ideas..


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## Chickenman35 (Jul 28, 2006)

Did you by chance get rear calipers from a Porsche Boxster? If you did those won't work. Period. 

Otherwise, the only thing I can think of is that you didn't push the caliper pistons back far enough when you installed the new pads. There should be zero difficulty with new pad installation with front Porsche calipers.

The note about the missing dowels concerns me. Are you talking about the pad retaining pins ( approx 1/8" in diameter, approx 4" long and held in place with small cotter pins)? Can you take a picture and post it up. You can buy those online at RockAuto.com, GermanAutoParts or even ECS Tuning. Any Napa or Autozone dealer should be able to order them as well.

Edit: Just reread post. Are you instead talking about the 3/8" diameter pad " locating " dowels that are *permanently* pressed into the caliper body? Those shouldn't be gone EVER!! Caliper is useless without them....not to mention highly dangerous


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## aFOURstance (Jan 31, 2011)

Chickenman35 said:


> Did you by chance get rear calipers from a Porsche Boxster? If you did those won't work. Period.
> 
> Otherwise, the only thing I can think of is that you didn't push the caliper pistons back far enough when you installed the new pads. There should be zero difficulty with new pad installation with front Porsche calipers.
> 
> ...


They're definitely fronts. As far as the pistons they're pushed back as far as they can go but the clearance with the new rotors is just nowhere near close to fitting it's about a quarter inch difference. Yes your edit post is correct those are the ones that are busted. Thanks


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## Chickenman35 (Jul 28, 2006)

aFOURstance said:


> They're definitely fronts. As far as the pistons they're pushed back as far as they can go but the clearance with the new rotors is just nowhere near close to fitting it's about a quarter inch difference. Yes your edit post is correct those are the ones that are busted. Thanks


Well...unfortunately those calipers are junk then.

Porsche Boxster front calipers ( base model ) will accept rotor thickness up to 25mm. Are you 100% sure they are fronts? Front Boxster calipers have differential piston sizes of 36mm and 40mm. Rear calipers can be identified by smaller pistons of 28 and 30mm. Some of the rear calipers will only accept a 20mm wide rotor. Depends on Part # of caliper. Porsche part numbering system can be confusing, so it's best to go by piston diameter as far as selecting Boxster calipers.

And you must use front Boxster calipers to mount on the front of your car. Rear calipers mounted on the front reduce piston area by 42.2% as shown in numerous other threads in this forum. That dramatically reduces braking force.

Link to psiton sizinz of Boxster front and rear calipers:

http://forums.vwvortex.com/showthread.php?7003812-Porsche-caliper-issue


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## aFOURstance (Jan 31, 2011)

Chickenman35 said:


> Well...unfortunately those calipers are junk then.
> 
> Porsche Boxster front calipers ( base model ) will accept rotor thickness up to 25mm. Are you 100% sure they are fronts? Front Boxster calipers have differential piston sizes of 36mm and 40mm. Rear calipers can be identified by smaller pistons of 28 and 30mm. Some of the rear calipers will only accept a 20mm wide rotor. Depends on Part # of caliper. Porsche part numbering system can be confusing, so it's best to go by piston diameter as far as selecting Boxster calipers.
> 
> ...


I'll definitely read up on this and figure out what to do from here I just may have to put the stock calipers back on..


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## bgcarter1 (Sep 22, 2013)

aFOURstance said:


> I'll definitely read up on this and figure out what to do from here I just may have to put the stock calipers back on..


that sucks! sometimes it makes you wonder why we spend our time and money to have everything go wrong, when we can just leave things stock... but its what we do :banghead:


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## Chickenman35 (Jul 28, 2006)

... it's a disease, of which there is no cure :banghead:


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## FastAndFurious (Feb 2, 2002)

People say they don't work but you have to make it work. The pins that hold the brake pads could be adjusted and I had to shave pad about 2mm to clear brand new 312x25 rotors up front
I just put boxster rears on front and rear of my mk4 chasis with R32 rear calipers for handbrake. The braking is much better then stock


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## Chickenman35 (Jul 28, 2006)

FastAndFurious said:


> People say they don't work but you have to make it work. The pins that hold the brake pads could be adjusted and I had to shave pad about 2mm to clear brand new 312x25 rotors up front
> I just put boxster rears on front and rear of my mk4 chasis with R32 rear calipers for handbrake. The braking is much better then stock


Did you miss the part that said the OP's calipers are missing a couple the large pad locating dowels?


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