# [DIY] Converting TT caliper to Boxster 986 caliper



## Chunki84 (Dec 18, 2008)

*Withdraw*

Don't want to mis-inform.

I learned from wheel adapter, so I checked many posts this time but obviously it wasn't enough 

I made few mistakes when I purchased parts and I don't want someone makes one because of my post.

I will post something else someday.


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## FatAce (Jan 30, 2012)

Awesome start to the thread! Be sure to follow up with installation photos.


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## Dark Zero (Feb 17, 2005)

Did you swap cross-tubes and bleeder valves around on the calipers? I thought it was necessary due to the calipers having a smaller/bigger piston and the original orientation on the Boxster compared to ours? Someone can correct me if its not necessary.


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## Chunki84 (Dec 18, 2008)

nope, don't have to. if you see someone changed them, that's because the parts can strip out easily. and people changed the parts with oem porsche caliper parts. I will not take them out when I painted the caliper, so i will not change them.


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## TheDeckMan (Sep 26, 2004)

Do not use aluminum adapter brackets. Way to many issues with them, make sure to get steel or an alloy that wont expand as a higher rate than the hub/rotor.


FYI 986.351.122 and 986.351.121 are the part numbers.


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## Chunki84 (Dec 18, 2008)

Adapters are alumium.. 6061/t1
i thought they were steel based on weight.
they are heavy..

I am worry now 

and parts number for what? i can not find any parts with that parts number. If you meant caliper, what I wrote in my original post 986 351 422 is correct number. I put the same number for both side caliper though. i need to edit.

add.: quick google search, 6061 is aluminum alloy. i need to check more detail on this


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## TheDeckMan (Sep 26, 2004)

Chunki84 said:


> Adapters are alumium.. 6061/t1
> i thought they were steel based on weight.
> they are heavy..
> 
> ...


Threads cant take the stress even in formed state, as well as the threadcerts also will pull out when exposed to high heat. 99% of the companies that make these parts have "0" engineering understanding or experience as they just knock off others.


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## PLAYED TT (Oct 17, 2010)

Chunki84 said:


> quick google search, 6061 is aluminum alloy. i need to check more detail on this


You don't need google when you have an engineer telling you.


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## Dark Zero (Feb 17, 2005)

Chunki84 said:


> nope, don't have to. if you see someone changed them, that's because the parts can strip out easily. and people changed the parts with oem porsche caliper parts. I will not take them out when I painted the caliper, so i will not change them.


I'm not sure if you misunderstood what I meant by this. I wasn't referring to swapping those parts out due to stripping out easily. The calipers on the Boxster is rearward on the rotor and for us its forward changing piston orientation. There's a small and large piston on each caliper which if I'm not mistaken the smaller piston is supposed to "see" the rotor first. AS they sit now, you'd be seeing the larger piston first. If you flip them (left to right) to see the smaller piston your bleeder valve would be on the bottom thus why they sway to swap the bleeder valves and cross-tubes top to bottom on each caliper. That's where you see some information about "reversing". I forget if the cross-tubes need to be swapped to the other caliper because of minor some difference or not.

Again, maybe I'm mistaken and this isn't necessary and some people got away with it as is and no issues.  I know the "reversing" is usually discussed regarding this DIY BBK.


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## TheDeckMan (Sep 26, 2004)

Swapping is not needed.


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## Chunki84 (Dec 18, 2008)

Dark Zero said:


> I'm not sure if you misunderstood what I meant by this. I wasn't referring to swapping those parts out due to stripping out easily. The calipers on the Boxster is rearward on the rotor and for us its forward changing piston orientation. There's a small and large piston on each caliper which if I'm not mistaken the smaller piston is supposed to "see" the rotor first. AS they sit now, you'd be seeing the larger piston first. If you flip them (left to right) to see the smaller piston your bleeder valve would be on the bottom thus why they sway to swap the bleeder valves and cross-tubes top to bottom on each caliper. That's where you see some information about "reversing". I forget if the cross-tubes need to be swapped to the other caliper because of minor some difference or not.
> 
> Again, maybe I'm mistaken and this isn't necessary and some people got away with it as is and no issues. I know the "reversing" is usually discussed regarding this DIY BBK.




Oh! I understand now! 

Good point. I checked few posts again and they don't mention about it.

If it's really matter, what if I swap Left caliper and Right caliper?

Piston touching order will be the same then. 

Not sure now.

If you can find the post, can you give me the link?

I have plan to install the caliper on friday, so I still have time.


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## Dark Zero (Feb 17, 2005)

Chunki84 said:


> Oh! I understand now!
> 
> Good point. I checked few posts again and they don't mention about it.
> 
> ...




Here's a random one I just searched for that mentions it. DaveB1970 seemed like the brake guru on the subject from what I gathered. I had an email with him with some information that I cannot find at the moment. Anyway its just information I found when I was searching about these calipers. If you don't need to swap like DeckManDubs stated above it might save you the hassle.

http://www.briskoda.net/forums/topi...ke-kit-porsche-brembo-4-pot-callipers-on-vrs/


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## Chickenman35 (Jul 28, 2006)

Apikol makes steel brackets. They are the ONLY material you should use. Far too many failures with aluminium brackets to even consider them.

http://www.apikol.com/index.php/products/braking/brake-brackets.html


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## Chickenman35 (Jul 28, 2006)

*Important. Do NOT use Banjo bolts on these calipers.* The factory Porsche design uses a hard line that screws into the caliper. The hard line then attaches to the flex hose. Edit: Picture of Porsche 986 front brake line and hose shown below:










Banjo bolts should only be used when there is a factory retention system used to prevent the Banjo from rotating and then loosening. All it takes is one rock or chunk of debris to hit the Banjo bolt and you have brake failure. Even the constant back and forth pull on the brake hoses while turning can loosen a banjo bolt if there is no anti-rotation device.

You should be using a direct Male/Male AN Fitting that accepts a thread on female end on the hose. I posted all of the Part numbers that are readily available from Russel ( and other suppliers ) to use Male/Male AN fittings. These cannot be knocked loose when struck by Debris. They also seal better and are less prone to stripping the threads out of the caliper. 

I'll see if I can find my post again with the Part numbers.

Found it. Post #11 in the following thread. Some good info included:

http://forums.vwvortex.com/showthread.php?5806725-Porsche-986-on-a-TT-1-8T-Quattro-%28Yes-has-been-done-but-need-to-some-help-getting-blanks-filled%29&p=80070714#post80070714


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## Chickenman35 (Jul 28, 2006)

Found it: 

*For the front lines you can easily build your own SS brake line setup using off the shelf parts from Russell. Far cheaper than the " Custom brake line kits " supplied by typical Euro Parts venders.

These are what I used on my Audi A4 986 Brembo SS line conversion ( front ).

All Russell parts:

Russell 656042 18" -3 AN Female/Female SS line ( 2 required ) Note: Check length. 18" is usually good, but you may require shorter or longer hoses for your TT than on my A4. 

http://www.summitracing.com/parts/rus-656042

Russell 640411 Brake adapter Steel, -3 AN to 10mm x 1.0 Female/Male ( 1 kit required )

http://www.summitracing.com/search?keyword=640411&dds=1

Russell 640431 Adapter Steel Male -3AN to Male 10mm X 1.0 Thread ( 1 kit required ) 

http://www.summitracing.com/search?keyword=640431&dds=1*


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## TheDeckMan (Sep 26, 2004)

DOT lines can be had from Four Seasons Tuning. Thats where I got my 19" ones.


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## l88m22vette (Mar 2, 2006)

Not to go against you Chickenman, since I know you know you're stuff and you were a big help with my clutch cylinder stuff, but my brakes have been fine for years and I used banjos on my 986 calipers...maybe I'll look into revising them once I get other little stuff squared away


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## Chunki84 (Dec 18, 2008)

l88m22vette, did u put copper washers? I wanna buy some in local stores but i can't find in local stores.


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## l88m22vette (Mar 2, 2006)

Yes I did, between the caliper and brakeline, and the brakeline and banjo bolt head (so: caliper || brakeline || bolt head)


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## Chunki84 (Dec 18, 2008)

where did u get?


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## Chickenman35 (Jul 28, 2006)

l88m22vette said:


> Not to go against you Chickenman, since I know you know you're stuff and you were a big help with my clutch cylinder stuff, but my brakes have been fine for years and I used banjos on my 986 calipers...maybe I'll look into revising them once I get other little stuff squared away


Sure..you can get away with it. Until it fails. I've taken short cuts with things as well. But I never take short cuts with brakes. I've seen brake failures on the race track and the result wasn't pretty. 

In addition to the facts already stated, consider that a Banjo bolt requires a spot faced machined surface to seal against. Is the area around the brake line spot faced on the Porsche calipers? Answer = No. They seal most of the time because Porsche has very good castings..but it's not right. And you're depending on luck again. What if the casting is a bit rough there? The caliper is designed by Porsche to take a taper seat fitting for specific reasons. 

I don't like trusting my braking system to luck and I don't want to see people possibly get hurt because of a failure that could have been avoided. That's all I'm saying :beer:


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## Chickenman35 (Jul 28, 2006)

Chunki84 said:


> l88m22vette, did u put copper washers? I wanna buy some in local stores but i can't find in local stores.


This is a perfect example of why using Banjo bolts in this situation can be dangerous. I don't know what " stores " you are referring to...but Home Depot, Lowes etc are not places where you should be buying Banjo bolt washers. Hopefully you weren't referring to those. 

Washers for Banjo bolts are made of a specific soft copper or aluminium so they will crush properly at the specified torque. In an aluminum caliper that torque is very low ( approx 13 to 15 ft/lbs depending on design ) . Use the wrong hardness of washer and the Banjo bolt can leak and possibly loosen due to improper crush. The big danger is loosening, because you are not using the required ant-rotation device.


Edit: Just to help you out if you insist on using Banjo bolts. Washers for Iron calipers can be a lot harder than washers for aluminum calipers. You run a risk of getting the wrong hardness of washer if you buy Generic brake banjo washers from Napa or Autozone. These washers are normally made for iron calipers only ( EG: Older American cars ) and quality varies a LOT!!

Now, a lot of Motorcycles use aluminum brake calipers and use Banjo bolts for attachment due to packaging constraints. ( The calipers are of course designed to use them with proper anti-rotation devices and spot facing ). Go to your local Sport Bike shop and take along your Banjo bolt. Get a GENUINE Honda/Suzuki/ Kawasaki etc, copper or aluminum washer that is used specifically on ALUMINUM calipers. Then you can be at least assured that the washer will be soft enough to crush properly. And of course they are a 1 time use only. 

I've said enough on this and made my point... to each his own. Good Luck with the build :beer:


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