Skip to content
View in the app

A better way to browse. Learn more.

Ultimate Subaru Message Board

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

Idle speed lowers w/brake applied

Featured Replies

I noticed that my idle drops ever so slightly when at a stop when I apply brake. Raises when I let off on brake. Just wondering if this is normal.

the sube, honda, and the caravan all do it. It has to do with the vacuum boost on the brakes

Your brake booster likely has a vacuum leak when you apply the brake. If it's not a large leak, everything will still work fine. A correct booster will cause a slight change in idle if you pump the brakes, but if you hold them in it shouldn't technically change the idle like your describing. I wouldn't worry about it unless it's severe.

 

GD

yeah it sounds like normal activity there. when you apply the brakes, the idle will drop slightly beacuse the vacuum booster kicks in and acts kinda like a slight vacuum leak. At least to the motor, because it's trying to replenish the vacuum lost from the booster on the brakes. my 2 sense n e way. I wouldn't lose any sleep over it.

Please sign in to comment

You will be able to leave a comment after signing in

Sign In Now

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.