Am currently having problems with my brakes in my 1984 300TDT. The car has strong brakes on the 1st pump but on the 2nd consecutive pump, the brake pedal gets stiff & I loose brakes.
I have a relatively new brake booster & newly rebuilt vacuum pump. Current vacuum at idling 20-22 and increases as the accelerator is pressed. I tried to plug the 2 small vacuum stems connected the main vacuum hose from the vacuum pump to the brake booster, but to no avail... still stiff brake pedal on a consecutive pump. Thus, eliminating all possible leaks from its branches, the leak source possible involves the vacuum pump, brake booster, and/or the main vacuum line. Can anyone help me with this? Can the main vaccum hose be the culprit?