# Spongy brakes.



## BlitzkriegB.C. (Dec 13, 2009)

So I recently had to replace my master brake cylinder due to it being well passed its life, I replaced it yesterday, bled my brakes today, and I still have spongy brakes,








I'm not sure if I should get new calipers as well?
I need some advice


_Modified by BlitzkriegB.C. at 10:34 PM 3-18-2010_


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## 1985zcar (Apr 19, 2006)

did you bleed the master before you put it in? there's likely still air in the system, try re-bleeding.


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## Autocross83gti (Nov 16, 2008)

*Re: (1985zcar)*

^^^^This!
Bench bleeding. Sometimes you can get away with not doing it. 
Try bleeding it with a pressure bleeder. Otherwise I'd suggest removing it and bench bleeding. 
Very worn pads can also make the peddle feel spongy.


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## BlitzkriegB.C. (Dec 13, 2009)

alright, ill bench bleed it, and then ill check the pads, 
thanks guys


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## 2lowcoupedoor (Mar 12, 2003)

*Re: (BlitzkriegB.C.)*

Keep bleeding it man. If that doesn't work remove it and bench bleed it.


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## jedipartsguy (Aug 24, 2006)

*Re: (2lowcoupedoor)*

if the bleeding doesn't work you *need* to check your wheel cylinders, make sure the seals are intact. if there is a lot of grease and brake dust collecting on or around the wheel cylinder that is your problem.


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## c25porter (Sep 12, 2006)

a "power bleeder" is about $40 and well worth the money.


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## Amsterdam087 (Dec 31, 2007)

do yourself a favor and pick one of these up, 
saves alot of time and questions. http://****************.com/smile/emthup.gif


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## Ghost762 (Oct 20, 2005)

*Re: (Amsterdam087)*


_Quote, originally posted by *Amsterdam087* »_do yourself a favor and pick one of these up, 
saves alot of time and questions. http://****************.com/smile/emthup.gif 









Now that's some Awesome Photoshop work. http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif


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## John222 (Oct 11, 2008)

*Re: (BlitzkriegB.C.)*

I'm interested in how this turns out, I also have an air bubble in my system. I replaced my flexible brake lines (they were showing signs of ballooning) but no improvement, still spongy. Getting tired of bleeding this thing. In the next couple of days I'm going to fully compress my front calipers to see if there is anything trapped in there. I'll then bleed them in the compressed state.


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## germancarnut51 (Mar 23, 2008)

*Re: (John222)*

Bleeding with the pistons fully retracted is tougher than with the pistons partially extended (used brake pads). The reason is that bleeder valve flow is restricted with the pistons all the way in.
People complain that they bled the brakes, and they still have spongy brakes. The problem is usually that the person/persons did not use the correct technique, and did not run enough brake fluid through the brake system. I have found that it takes at least 1.5-2.0 quarts of brake fluid drawn through the four bleed valve to get good clean fluid, and absolutely on air left in the system. Looks to me like most people draw one 12oz bottle or two tops. 
That simply, is not enough.
Other people get in there and pump the brake pedal like crazy, without pausing at the bottom, closing the bleed valve, allowing the pedal to rise, and waiting for the master cylinder to refill with fluid before depressing the pedal again, and opening the bleed valve again. This does not bled the air from the system at all and is a waste of time. You must wait between pedal down cycles for the master cylinder to refill from the reservoir, and close the bleed valve at the bottom of the stroke to prevent air from entering the bleed valve when you release the brake pedal.


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