Topic: 79 front/rear disc brakes

[dgilleland]

My 1979 does not get driven that frequently,  All the brake components where replaced about 8 years ago, SS lines, hoses, calipers, master, proportion valve, booster, ect.  Went to move the car out of the garage for something and the brake light came on and the pedal felt a little soft.  Took a look and the rear bail of the master was empty but I could find no fluid on the garage floor or a leak at the master or hoses.  Filled up master and started bleeding at the rear with a vacume pump.  Seems like I am getting air from somewhere with some fluid,  is it possible the master could be faulty.

[Stringer]

It could be.  If it is slow seepage the fluid could evaporate without much indication of a puddle.  Check for moisture (fluid) along the path of travel for the fluid.  At the brake boost it would travel along on the underside, down the firewall, to the sub frame on the driver’s side.  I had a master cylinder cap that leaked and left very little indication but upon further inspecting you could see that the sub frame was moist from the slow leak.   Check all four corners of the vehicle along the brake lines for similar signs.