Ive got a 89, stock brakes. as long as i drive it every day its fine. if i let it sit for more then three days then the master cyl drains and the brakes dont work. i think i have a leak in the master cyl and its not holding pressure. i want to just upgrade to the Z brakes but cant find em. should i just find a used master cyl or go for the z brakes now?

 

find out if you have a leak or not then fix the problem. upgrades can wait till latter.

 

...Unless the master cylinder is the source of the problem. Then I personally would go ahead and upgrade if you have the $$$$$ to