In what way can my brakes effect idle?

[PKRWUD]

The power booster is the big round can mounted on the firewall, right in front of the driver, in the engine compartment. The master cylinder is mounted to it. It will have a fat hose going to it. With the engine off, disconnect that hose from the booster, and plug it (the hose). Use a fat bolt, or a sharpie marker, etc., just make sure it's plugged. Don't worry about the hole left behind in the booster.

Start the engine, and compare the idle quality with the way it was before. Is it better? Has the unevenness that smoothed out when you applied the brakes gone away? If it has, you have a pinhole in the booster diaphram, and the entire booster will need to be replaced. DO NOT drive it with that hose disconnected and plugged. You will have virtually no brakes, so make sure you reattach the hose when you are done testing.

Personally, I don't think this is your problem because a vacuum leak will raise the idle 9 times out of 10, rather than lower it. Still, test it and see. Post your results.


Take care,
~Chris