How difficult is it to do this modification? I just purchased 997 rear calipers to go with my 380 mm Stoptech 6 piston front calipers because of the front brake bias. I tried the 350 mm 997 rotors with Pagid Blacks and stock 996 turbo rear calipers but am still getting front brake bias that is engaging the antilock system prematurely. If its not too difficult I will do this mode and will need your custom line. Is there a DIY for this modification? Thanks.

 

The 997GT3 Brake Master swap is fairly straight forward. Place a bunch of paper towels under the reservoir so you do not spill fluid anywhere and then have a mess to clean up. Brake fluid is corrosive and will eat paint! You need to empty the fluid out of your brake fluid reservoir. I just used my motive bleeder to pressurize and drive the fluid out by bleeding out one of the calipers. Once empty, disconnect the plastic line that plugs into the pre-charge PSM pump under the brake master. To disconnect, push in the plastic collar on the line at the PSM pump, then pull on the plastic pipe and it should slide out easily. Do not force it! Next step is to pull straight up on the empty brake fluid reservoir and it will pop out of the brake master. Gently wiggle it side to side as you pull up and it will eventually pop out out of the rubber grommets.

Next, remove the big nuts on the brake booster (24mm I think) and the brake master will slide out. Installing the new master is the reverse. Just make sure the brake push rod properly engages the input shaft on the new master as you install it.

The biggest pain in the installation was the fabrication of the 12mm/10mm line. I went through the adapter route which was not really optimal and even had a local brake shop make me a new line with custom flare. The tool they used was the $50 cheapie flaring tool and the line ended up leaking. It was not until I purchased a professional brake flaring tool that I was able to make a professional OEM quality line that was to my satisfaction. Finally, after everything is installed, and prior to filling the reservoir with fluid, I would recommend pressurizing the whole system to check for any leaks. I did this by connecting my Motive bleeder, pressurizing the empty brake fluid reservoir to 25psi, and left it connected overnight to make sure everything held tight. It's a lot better to find out if you have a leak somewhere prior to having a reservoir full of fluid and creating a mess. Hope that helps...

You will find this a great mod because it substantially firms up the brake pedal especially if you increase the size of you brakes.

 

it would be a while before i do any type of brake upgrades but if your making the needed line then put me down for 1

 

I was able to find the 997 GT3/997 Turbo brake master cylinder (OEM part number 99735591030 manufactured by TRW) on Ebay for $256.76 with free shipping. I also found the part at Koperformance.com for $265.27 and Importecautoparts.com for $265.08.

I am not affiliated with any of these websites and am posting this information just in case anyone is thinking of doing this modification.

 

Thanks guys! Just ordered one through KO and a brake line from Pwdrhound. The Porsche prices are nuts at the dealerships...

 

TRW is the OEM manufacturer. Same exact part. Good stuff...

 

ordered my brake line today. guess i need to to start stockpiling brake parts now!

 

wow. rep to pwdrhound! When I work my way back to the brakes I am going to bypass the psm pump

 

Hey Tim,
I looked at bypassing the PSM pump, removing it and going directly from the brake master to the ABS module both of which would be a 12mm line. This can be done but you will end up having the plug one of the plastic brake fluid supply lines that connect the brake fluid reservoir with the PSM pump. I did not want to do that and risk a leak down the road. Another option would be to use the GT2 reservoir but that has a supply line that goes to the ABS module so not ideal either. In the end I just retained the PSM pump as is (it only weighs about a pound or so) with the reservoir plastic lines plugged into it as intended by the factory. My PSM pump, however, is disconnected via a trunk mounted on/off switch that is wired to its power supply cable. This gives me the option to have fully functioning PSM (if I wanted to) by simply flipping the trunk mounted switch to ON. I always keep it OFF however as I have a GUARD LSD on the car. Hope that helps...

 

LOL.. We our looking at the same pro's, con's and solutions. I am dieing to set up the traction control on my motec but time is not on my side as always. 17 days till the car is in the trailer to Texas..

 

Im also in for one set of all required lines for the update if you are still producing these
You can send me an pm with all the datas?

 

Got this after the install, feels like car brakes better in front .
Didnt have any issues like this before.
I have front Brembo 8 piston and rear 997TT rear brakes.



Comments please and help.

 

Have no idea. That's why I hate using mix and matched aftermarket parts. I have no clue what the piston area is of the Brembos but I would probably use the Brembo brakes in the rear as matched set. Why did you use the Brembos instead of the Porsche/Brembo calipers? There is absolutely no issue with those. Good luck...

 

I just changed the cylinder now and never had an issue with that setup with the oem cilinder, that was the only thing I changed.

 

I have no idea then. The larger master is a proven swap on these cars. The larger master just moves more fluid both front and rear. I'd say something else is at play here. Hope you get it sorted...