I happpened to turn off the engine while coasting down the driveway, and I noticed that the brakes feel the same with or without the power assist. Is that correct? You wouldn't want to be without enough braking power.

If the brakes should be more touchier with the engine running, then I think there might be a a problem with the check valve.

thxZ

You should notice a difference. For whatever reason you're not getting proper assist. I would just be guessing as to why.

I can only think of three possibilities:

1- there is no vacuum getting to the brake booster.

2- Assuming the brake booster works, it isn't utilizing the available vacuum (leaks.)

3- The booster is broken, so it won't work anyway.

thxZ

you could also have residial vaccum from the 280z's larger master vac. Try hitting the brakes several times while coasting engine off. Or better yet remove and cap off he line and drive around the block. You'll notice a diff. (assuming it was working before you did your experiment)

Assuming you're like most folks and you hold your foot to the brake when you start the car, as soon as the engine fires up you should feel the brake pedal getting 'sucked' down a bit further from the added vacuum assist. At least that's how it feels in my 280 ... perhaps it's a bit different in a 240 or 260...

.. but I can tell you one thing, if you had a 280, you'd notice if you had a pretty sizeable vacuum leak (i.e. in the booster) -- does pretty funny things to the idle on these cars...