Start farthest away when bleeding. MC, Air pack, Rt RR, lt RR, rt INT, lt INT, pax FT, dr FT. Are you adding fluid, is it empty/low before you re bleed? Does your truck still have the fording stuff attached? A failed air pack can push brake fluid out of the blow by tube if all that stuff is still in tact.
If the air pack is stuck/not working, you will still have brakes, but they will be very stiff and the truck will be hard to stop but you might think that that is normal because it is old school. If the air pack was stuck and freed itself up when driving, this usually happens with a hard braking event, brake fluid will pizz out the blow by tube and leave a mess on the pax side front axle area.
To see if the fording stuff is still hooked up, engine off but air in the system. Step on the brake pedal. If the fording plumbing is in tact, you will hear air venting out of the blow by tube.
Another issue, especially if the fluid isn't low but is added when bleeding, is the MC bypassing. You will have no pedal/resistance, goes right to the floor. If you step on the pedal a few times, pedal can return, you'll bleed and think it was just air.
The next time you have no pedal, take the MC cap off, look at fluid level. If full, most likely a MC issue. Put your hand on the pedal and depress it just enough to contact and move the piston to uncover the vent hole. Look for fluid/air to come out of the hole. If you press the pedal hard and release it, there should be a small geyser of fluid come up out of the fill hole. Bubbles out of the hole means air in the system.
Remember, there needs to be freeplay in the pedal BEFORE the rod contacts and starts moving the piston in the MC. Pedal needs to move, rod needs to move, THEN contact the piston. If no freeplay/piston not fully returning, bleeding is futile.
