Brake question....need answer ASAP please

[Slammed70]

Working on this truck, dude tells me that hes caliper exploded, which come to find out his rotors were so thin the piston inside of the caliper pushed its self out. Then he let it sit on the side of a road for a few days finding a tow, with the piston out of the caliper and the system open like that....he put new rotors, and a caliper on it, called me over to help him bleed it. Bled just fine, good pedal. Now were ready to go for a drive and bam, no pedal. Goes straight to the floor. Hes telling me that when he put it all back together, there was no brake fluid in the resevoir on on the master cylinder.

Now, Im not certain here, but Im thinking he lost all the fluid and ran the master cylinder dry. If thats the case, just wondering if there is a way to bleed the master cylinder on the truck, that doesnt require hours and hours of pumping on the pedal.

Thanks,
Mitch-