[WB72]

Back story...
Everything is new except proportioning valve, which the piston moves freely.

I can’t get firm pedal on rear. The piston continues to trip and not allow the brakes to bleed the rear. I know there is a tool to install where the sensor is located to stop it from tripping.


There are posts mentioning to use a clamp or hold the pin on the front to reset the piston, but this only works if the front brakes have low pressure.

These tools are just a few bucks, but is there a way to block the piston without the specific tool as I would like to get this done without ordering this specialty tool.