I would not suggest modifying anything just yet. One has to identify the problem first.
Step # 1. Make sure the "L shaped" bracket rod is installed correctly as it will affect travel and pedal leverage. be aware that some cars have multiple holes in the pedal arm for power or manual brakes. MAKE SURE you are installed correctly
Step # 2. Eliminate as much play or slop in the linkage as possible .030 at the master over a 6 inch distance multiplies significantly
Step # 3. Install pressure gauges on the master and verify the pressures being generated. Panic stop should be ~ 1500lbs.
note the pedal travel required. With the gauges(s) preferably on on each port note the amount of travel required, it should be very minimal unless there is excess play in the linkage or adjustment, something is moving/ flexing under the pressure, the master is bad. If you don't have 2 gauges you can get by with 1 by plugging the second port. that requires retesting the second port.
test kits are available relatively cheap on AMZ
BRAKE PRESSURE TEST KIT may also be cheaper elsewhere.
Step # 4. Once you have established the pressures are being generated at the master you can the move to the calipers preferably one end at a time while blocking the other port of the master. You should see the SAME pressures at the calipers. While doing so again look for any flex or excess movement
Step# 5. repeat at opposite end.
By this time you should have enough data to indentify the problem and or rport back as there are a few other gremlins that are possible.
