sam,
thanks for getting back to me. first off the car is a 1983 300td with 179k on the engine and chassis. i have the luxury of having a best friend that owns/operates a wrecking yard, so parts costs are not an issue for me, hence my decision to replace the pump. also, when i tested te pump with a vacuum gauge it was pulling less than 15hg @idle and was sporadic at best. my biggest concern, as is yours, are the power brakes. i have done a leak down test on all of the lines and connectors within the engine compartment. none there. i have not tested the door/trunk system, and don't know if i really want to. how do you block that system off? i have also done the "pedal test" to check the booster, but is there a more accurate way to test the booster for leaks? thank you for the vacuum diagram. i have seen that one, but i can never get it blown up enough to read the labeling and really understand it. do you have an exploded version of this? i can't htink of anything else to tell you, but please let me know what other info you might need to help me diagnose my issue. thanks again.