SHORTLY AFTER MODIFICATIONS TO THE PA11'S BRAKE/STEERING SYSTEM BOTH FAIL DURING TAXI INTO POSITION ON THE RWY FOR TKOF.

Narrative

I HAD LANDED THE HIGHLY MODIFIED PA-11 FOR A FUEL STOP. UPON LNDG; THE BRAKES FELT A LITTLE MUSHY; BUT NOT UNUSABLE. THIS PARTICULAR ACFT HAS NO INTERCONNECT BTWN THE RUDDER AND THE TAILWHEEL; AND STEERS ON THE GND BY DIFFERENTIAL BRAKING ONLY. AFTER FUELING UP; AS I WAS PAYING MY BILL; THE LINEMAN MENTIONED THAT 3 FAA INSPECTORS WERE THERE AUDITING THE FBO. I DIDN'T THINK MUCH OF IT AT THE TIME. I RETURNED TO THE ACFT; TAXIED OUT; ABLE TO MAKE A L TURN OUT OF MY PARKING SPOT; ANOTHER L TURN ONTO THE TXWY; A R TURN TO THE HOLD SHORT LINE; STOP AND MAKE A RADIO CALL. HOWEVER; AS I TAXIED OUT ONTO THE RWY TO TAKE OFF; I MADE ANOTHER R TURN TO CTR UP ON THE RWY; AND SUDDENLY I HAD NO BRAKES AT ALL. I ATTEMPTED TO CTL THE DIRECTION OF THE ACFT WITH RUDDER ONLY; WITHOUT SUCCESS. MY R TURN CONTINUED UNTIL I DEPARTED THE RWY ONTO THE GRASS SHOULDER. I SHUT THE ENG OFF AND EXITED THE ACFT. THERE WAS NO DAMAGE TO EITHER THE ACFT OR ANY ARPT STRUCTURES. I WAS ABLE TO PUSH THE ACFT BACK ONTO THE RWY BY MYSELF. AFTER I HAD DONE SO; A LINEMAN FROM THE FBO DROVE OUT TO SEE IF EVERYTHING WAS OK. HE MENTIONED TO ME THAT THE 3 FAA INSPECTORS HAD SEEN THE WHOLE INCIDENT. I HAD THE LINEMAN HOLD ONTO A WING STRUT WHILE I RESTARTED THE ENG AND WE 'WALKED' THE PLANE BACK TO THE TARMAC. THE FAA INSPECTORS APPROACHED AND ASKED WHAT HAD HAPPENED. I EXPLAINED THE SITUATION TO THEM AND TOLD THEM WE WERE GOING TO FIX THE PROB. THEY ASKED TO SEE MY PLT CERTIFICATE; MEDICAL; AND THE ACFT'S PAPERWORK; WHICH I PROVIDED. ALL WAS IN ORDER; AND THEY COMMENTED TO THAT FACT. 'THERE IS NO PROB HERE' ONE OF THEM SAID; AND HE TOLD ME TO GET THE PROB FIXED BEFORE I ATTEMPTED TO FLY THE PLANE AGAIN. AS THIS ACFT IS IN THE 'EXPERIMENTAL' CATEGORY; WE (THE LINEMAN AND I) ATTEMPTED TO TROUBLESHOOT THE PROB OURSELVES. WE FOUND THAT A COMPRESSION FITTING ON EACH BRAKE WAS LOOSE (THE BRAKE SYS HAD JUST BEEN MODIFIED BY AN FBO MAINT SHOP PRIOR TO THIS FLT). WE TIGHTENED THE FITTINGS; ADDED MORE HYD FLUID AND BLED THE BRAKES. I TESTED EACH WHEEL FOR RESISTANCE WITH THE BRAKES APPLIED; AND FOUND THEM TO BE SUFFICIENT. I STARTED THE ENG; TAXIED AROUND AND FOUND THE BRAKES TO BE QUITE EFFECTIVE. I DEPARTED THE ARPT AND FLEW TO HOME BASE. I FOUND THE BRAKING TO BE ADEQUATE UPON LNDG THERE; AND IMMEDIATELY HAD OUR MECH INSPECT AND ADJUST THE BRAKES. THERE ARE A COUPLE OF THINGS THAT I WOULD DO DIFFERENTLY; GIVEN THE OPPORTUNITY TO 'REDO' THIS SITUATION. I NOTICED UPON ARR THAT THE BRAKES FELT A LITTLE MUSHY; I SHOULD HAVE PAID MORE ATTN TO THAT. THERE WERE SIGNS THAT A PROB EXISTED; AS BRAKE FLUID WAS ON THE TIRES AND AROUND THE CALIPERS. ALSO; I THINK BOTH MYSELF AND THE FBO MAINT SHOP SHOULD HAVE BEEN MORE VIGILANT ABOUT CHKING THE BRAKES OUT; SINCE THEY HAD JUST BEEN WORKED ON. I MADE AN ASSUMPTION THAT THEY HAD 'TAKEN CARE OF THINGS.' THAT'S THE KIND OF STUFF THAT KILLS PLTS. LESSON LEARNED.