still no serial number found? looked at all the suggested locations, brushed off the paint to make sure. The front axle has this number stamped on the housing,...(not sure it's any help) 502413700B. I also tried to bleed the brakes, the fluid would come out of each wheel,..but could not develop any brake pedal. Do you think it is the master cylinder? If so, would a picture of the master cylinder be helpful? I cleaned off the paint on the motor,...it says Yale. Thanks for your help!