62MackB85FT

If anyone looking for master and there’s is a wagner casting, give them a call. They looked up truck and were able to find what master cylinder needed. Turned out to be MC2842, still in production and readily available all over online. Never been the case on this rig in last 5 years, guess first for everything 

Leak in master, once past 10 psi on power bleeder the master cylinder started leaking. The more pressure the worse it got. Guess I’ll be looking for a new one or trying to rebuild it.

Did bleed per manual in correct order. Did it manually and it does recommend pressure bleeding. Thinking of picking up a motive power bleeder and giving a try

Yep, bleed was with engine off

Brakes go to floor initially, then as pumped the pedal stays higher and firmer to the point brake feels good. If pressure is kept on pedal, brakes stay firm and pedal high. But once pedal let go, 20 seconds later pedal goes to floor again until pumped. Plenty of fluid, did system bleed including two on hydrovac (tandem piston cylinder style). Lines look good, not losing fluid. Any ideas why brake is soft before pumped?