# Brake bleeding

**URL:** <https://community.cartalk.com/t/brake-bleeding/30386>\
**Category:** Maintenance/Repairs\
**Tags:** brakes\
**Created:** [May 12, 2009, 10:34pm UTC](https://community.cartalk.com/t/brake-bleeding/30386 "2009-05-12T22:34:32Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![jdgsr57](https://avatars.discourse-cdn.com/v4/letter/j/e36b37/32.png) [@jdgsr57](https://community.cartalk.com/u/jdgsr57)\
**Post date:** [May 12, 2009, 10:34pm UTC](https://community.cartalk.com/t/brake-bleeding/30386/1 "2009-05-12T22:34:32Z")

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I have a 1995 chevy blazer 4wd 4dr (vin-w)  
  
 I changed all 4 brakes and the brakes are still spongy after bleeding the brakes-why?  
  
 Do you bleed the brakes with the blazer  
  
 running or stoped?

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**Author:** ![BustedKnuckles](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/bustedknuckles/32/25_2.png) [@BustedKnuckles](https://community.cartalk.com/u/BustedKnuckles)\
**Post date:** [May 12, 2009, 10:41pm UTC](https://community.cartalk.com/t/brake-bleeding/30386/2 "2009-05-12T22:41:32Z")

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Bleed the brakes with the engine off. It keeps you from sucking up too much exhaust fumes.

With the engine running, does pumping the brakes make a firmer pedal? If so, you may have a master cylinder going bad. After 14 years of service, this is not uncommon.

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**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:** [May 12, 2009, 10:42pm UTC](https://community.cartalk.com/t/brake-bleeding/30386/3 "2009-05-12T22:42:41Z")

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You may need to rebleed the system, starting with the cylinder farthest from the MC.

Here’s a tip to prevent entry of air into the lines.

When you open the bleeder to push the pistons back, put a clear plastic tube on it with the other end submersed in a clear plastic bottle hung near the bleeder and 1/2 full of brake fluid. As you push the piston back, the air contained in the tube will burp out and any drawback will pull back only new fluid without air.

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**Author:** ![vtcodger2](https://avatars.discourse-cdn.com/v4/letter/v/e68b1a/32.png) [@vtcodger2](https://community.cartalk.com/u/vtcodger2)\
**Post date:** [May 12, 2009, 11:37pm UTC](https://community.cartalk.com/t/brake-bleeding/30386/4 "2009-05-12T23:37:30Z")

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What mountainbike suggests will work. I’ve often had trouble with it – tubing falling off, etc. But I think that’s because of my poor character and sloppy workmanship, not because it is a faulty approach.

An alternative is called “gravity bleeding”. It works sometimes on many vehicles and is less work, although it is slower. Basically, you fill up the master cylinder, crack a bleeder and watch the fluid coming out. When it is clear and bubble free, close the bleeder. Top off the master cylinder occasionally. It won’t do any harm to look up the details on the Internet using a search engine. Maybe you’ll find out something important that I don’t know.

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**Author:** ![meaneyedcatz](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/meaneyedcatz/32/692_2.png) [@meaneyedcatz](https://community.cartalk.com/u/meaneyedcatz)\
**Post date:** [May 13, 2009, 3:11am UTC](https://community.cartalk.com/t/brake-bleeding/30386/5 "2009-05-13T03:11:23Z")

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I have always gravity bleed. It works.