DasBoost

If you add the 997 GT3 master cylinder (27mm bore) to the 996  in order for the psm/abs to work perfectly and not throw any codes you will need to install a brake bias adjuster in line between the rear master port and the psm pump, it needs to see about 7% reduction in pressure or it will throw a psm/abs code and shut down the system.  Note the 997 gt3 master has both ports 12mm bubble flair, unlike the 996 masters that use 12mm front, 10mm rear so you will have to make a custom line or a adapter (they suck)   Anyway it gives you a rock hard pedal with the 997 or bigger brakes and all works as it should

you can run the pump alone using a +12v jumper wire, then bleed with motive while pump is running. Will not of course cycle the valves tho.

have you gotten anywhere with the pump/valve activation ?? Same issue here, replaced master cyl, conventional bleed done, good pedal feel but at exactly 33 mph the abs/psm light goes on and disables the abs...arghhh drives be nuts ! BTW on dirt the abs/psm is working perfectly below the 33 mph. 30 mph,dirt,stand on brakes, abs functions as it should, same with psm in a corner. And also I did hook 12v to the pump and ran it a bit. No change.

Hello, Just signed up but I have been watching for a time. I have a 01 996tt evo stage 4, pss9, ect. This looks like a very nice site, at least I could sign up and post right away. LOL

I am retired and ran my own race engine shop for 20+ years, no Porsche but we did sprint car motors, winston west, northwest tour, tons of drag stuff from SS to TAFC and TAD. I also ported more heads than I care to remember. I also raced dragboats (Iwas the only one dumb enough to drive it) for 12 years. Now i'm just old and cranky. I trapshoot, hunt, train my dogs and still mess with cars.

Looking foward to learning more about these cars and working on the motor.