Soft brake pedal

[iontrap]

A few months ago I replaced the front pads on my car and since then the pedal has felt soft. The brakes work fine but the pedal just doesn't feel the way it did before replacing the pads.
Does anyone know what is going on?

 

[OneQuartLow]

Spongy pedal or just not as grabby as you'd like?

Is there a change after they warm up, after you stop a few times? You may have unknowingly changed compounds. Did you note the brand/style of pads? Ask the supplier what type they are.

Did you bleed any fluid during the pad change? If so you may have allowed some air into the system. That'd be a spongy pedal and means another bleed is in order.

 

[tadaima]

Ditto that, looks like it needs bleeding, also did you top off the brake fluid?

 

[iontrap]

Spongy is a good way to describe it, I have to push the pedal farther than before and there is no change after warm up. But, I believe these are a different compound than the OEM's I replaced. It is possible that some air got into the lines. I did bleed the master cylinder but not the lines at the wheels. I'll try bleeding them this weekend.

Thanks

 

[lubechick]

Did you by chance change the brake fluid lately? If there is accumulation of moisture in your brake fluid, it may reduce the boiling point significantly. The reason we like brake fluid not to boil is simple: Brake fluid is subject to high temperatures in the brake calipers, so when it boils, it liberates small bubbles of gas. These bubbles collect and become trapped in the system. Since gasses are compressible, we now have a soft, or spongy brake pedal. JUST ANOTHER POSSIBLE SUSPECT for your spongy brake pedal...

 

[iontrap]

lubechick,
This is possibly the problem, I actually did add a little fluid to the reservoir, about an ounce. I'll definately have to check the fluid level to make sure it's not overfilled.

Thanks

 

[tadaima]

Did you properly bleed them: bleed the corner which is the furthest away from the master cyclinder. Make sure to tighten the screw when depressing the pedal.

 

[iontrap]

Thanks to everyone for replying. It looks like I'll have to recruit my wife to help me bleed the brakes this weekend.

 

[RobZ71LM7]

When you replaced the front pads did you crack open the bleeder first before compressing the piston? If nto be sure and do it from now on backflushing the system can result in a poor pedal and damage the abs modulator as well as other parts.

 

[iontrap]

RobZ71LM7,
That is something that I didn't do. Would it be necessary to also loosten the cap on the brake fluid reservoir?

 

[RobZ71LM7]

quote:

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Originally posted by iontrap:
RobZ71LM7,
That is something that I didn't do. Would it be necessary to also loosten the cap on the brake fluid reservoir?

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You don't havee to if you crack open the bleeder as all the fluid comes out the bleeder screw. I didn't use to crack them open either til a brake tech told me about it. Chances are no permanent damage was done but it's best to crack them open. Later I looked in my GM service manual and it too warns about cracking them open to prevent damage. Many mechanics don't bother because they always got away with it in the pre-abs days when brake systems were much simpler.