I had a look at the servo piping in the engine bay yesterday because the brakes needed standing on to stop the van. There was a split near the end of the pipe, so fixed that and replaced the pipe and now the brakes are a little easier to operate. However, the pedal is still pretty hard - not that soft feeling you normally get with servo assistance. How much difference should the servo make to the pedal pressure / feel?
It halves the effort needed. I added one to my "drums all round" early and it locks up easy peasy. I'd look for more leaks with a piece of hose and the engine running. Another check is to let it idle and press the brake pedal - does the engine speed change? To test the servo, pump pedal (engine off), then while holding foot firmly on pedal start the engine (you may have to swap feet). The pedal should drop an inch or so as the engine starts. You might need a few revs if it just splutters into life at tickover. If the servo is good, try replacing the pads and shoes and avoid hard braking for a few hundred miles to "run them in". This makes a big difference.
Mostly new brakes and a new servo. Pedal doesn't drop noticeably on start up. What's the best way to find any leaks - seems tricky when looking for a vacuum?
Engine running, use a piece of hose as a stethoscope along the length of the pipe to servo. If it's old cotton braided stuff I'd replace it - it'll look much worse after you take it off. There must be a large leak to prevent the servo working, or the servo itself is broken. 30 mins after running mine yesterday, I had to seperate the master cylinder from the servo - there was a satisfying hiss as the vacuum was released which it had held for all that time. I was very happy.
