[eeyang92]

I've always been wondering this ever since I boiled my stock fluid and my pedal became spongey (since replaced with race fluid a couple times) - what is considered a "firm" pedal?

If I press on my pedal with my engine on (while at a stop), I'll feel the point where it "bites", and then there's a slight bit of movement, but I suppose I have to put some force to really move it. Is this normal or should it actually be "firm" as in it really should not move at all?

[M Fifty]

With the engine off pump the pedal a few times and then see how firm it feels. If it still feels a bit springy, you might have some air in the system.

HTH

[eeyang92]

Originally Posted by M Fifty

With the engine off pump the pedal a few times and then see how firm it feels. If it still feels a bit springy, you might have some air in the system.

HTH

It's rock hard if I pump it a few times. But IIRC it always felt that way even if I had air in the system since the air is being compressed by the pressure.

[M Fifty]

If it's rock hard with the engine off and the brake servo assistance depleted, there's no air in the brake lines or calipers.

Sponginess would indicate that there is air present as it compresses while brake fluid doesn't. Hence, when you boiled the fluid and gas bubbles formed the pedal felt spongy and the brakes became less effective as less pressure was being applied to the pads.

Once more, HTH.