# Brakes booster 101 **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** nissan, pickup\ **Created:** [July 27, 2017, 4:06pm UTC](https://community.cartalk.com/t/brakes-booster-101/106309 "2017-07-27T16:06:45Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![familyguy](https://avatars.discourse-cdn.com/v4/letter/f/f07891/32.png) [@familyguy](https://community.cartalk.com/u/familyguy)\ **Post date:** [July 27, 2017, 4:06pm UTC](https://community.cartalk.com/t/brakes-booster-101/106309/1 "2017-07-27T16:06:46Z")
jump in truck this morning.starting driving got to stop sign and hit brakes the brake pedal was hard as a rock so i’am guessing brake booster right or brake booster check valve. ---
**Author:** ![eddo](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/eddo/32/2594_2.png) [@eddo](https://community.cartalk.com/u/eddo)\ **Post date:** [July 27, 2017, 5:47pm UTC](https://community.cartalk.com/t/brakes-booster-101/106309/2 "2017-07-27T17:47:55Z")
depending on your vehicles set up (sorry, i’m not very familiar with Nissan’s,) this could be a vacuum leak or a p/s fluid leak (depending if your booster is vacuum operated or hydraulic.) or, as you said- a booster or check valve. ---
**Author:** ![the\_same\_mountainbike](https://avatars.discourse-cdn.com/v4/letter/t/c89c15/32.png) [@the\_same\_mountainbike](https://community.cartalk.com/u/the_same_mountainbike)\ **Post date:** [July 27, 2017, 8:24pm UTC](https://community.cartalk.com/t/brakes-booster-101/106309/3 "2017-07-27T20:24:39Z")
> [@familyguy](#): > > i’am guessing brake booster That would be my guess too. Try this: with the engine off, pump the brake pedal until it becomes hard. Then, while pressing on the brakes, start the engine. The pedal should sink a bit and get a softer feel. If it stays hard, your booster is bad or the check valve in the vacuum line is stuck closed.