How do you get a firm brake pedal? Will a gravity brake bleed result in a firm pedal? I have done the 2 man brake bleed method and I have tried the one man vacuum pump method but the brake pedal is not firm.

How do you do an effective gravity brake bleed?

Is stainless steel brake lines the only way to get a firm brake pedal? But some honda acura techs can get a firm pedal with oem rubber brake lines. How do they do it?

 

yes im interested too

 

Stainless steel lines improve brake pedal travel a little bit. Not astronomically.

Liquid does not compress. Air does. So bleeding your brakes to get a firmer pedal only works if there is air in your lines. If there's no air in your lines, bleeding them is useless.

This might help:

Fluid dynamics states this: example: Imagine a piston inside a cylinder like in an engine.

If you push down on a 1sq. ft area piston with 10lb of force, and that piston leads via a line to a 10sq. ft. area piston, it will apply 10lb ft of force per square foot. So: 10x10= 100lb/ft. Force was magnified from 10lb/ft to 100lb/ft by using surface area.


You can magnify force by applying the force onto an larger area using enclosed fluid.

Very simply put:

bigger master cylinder + smaller brake(wheel) cylinders = firmer pedal

Bigger brake(wheel) cylinders + smaller master cylinder = softer pedal

Thats why the ITR master cylinder piston is big, and the Civic CX master clyinder is small. The piston sizes have to remain proportional for the brake pedal to feel nice.


You can also get a firmer pedal thru harder compound brake pads that have a very low compression delta.

The brake pedal itself also flexes over time. Also, seals inside the system can wear. If you want a new feeling pedal, use a large brake master cylinder with new seals. replace calipers or seals inside calipers.

However, using an ITR master cylinder and CX brakes means that you have to push the pedal a lot harder to get the same effect.

 

Just keep bleeding with the two-man method. It takes a while to eliminate all of the air. Bleed the rear brakes first and then the fronts.

 

This is the 2 man method that I am using but it does not result in a firm pedal:

http://www.zeckhausen.com/bleeding_brakes.htm

 

or you also might have a shitty master cylinder. that was my problem

 

Someone told me that the best way to a firm pedal is a gravity bleed: open one bleed screw and letting the brake fluid drip out with out pumping the brake pedal, then close it up and move on to the next bleed screw. In addition never let the fluid go below the low mark on the MC. Has any one tried this technique?

 

Just do the two man method. Hell, get your mum to help you. Its very easy.

 

arsenal, it is not a question about easy or not easy.

I have a DA but I have done the 2 man bleed on a DA, DC2, 89 integra, 88 accord and never could get a firm pedal. I have also installed 2 new oem MCs and did the 2 man bleed but no firm pedal.

 

Well then your doing something wrong.

If your not bleeding it correctly then the air will stay in the system, resulting in a mushy brake pedal.

Only other thing is if your pads or discs are low.

 

James Richard Bean, Arsenal, if you don't have something valuable to add, keep your negative b.s. to yourself

 

lol. Got this in a PM aswell

" nb0 (6:27 AM 7/7/2007): If all you have to say is bullshit, keep it to yourself.
Arsenal (2:16 AM 7/8/2007): ?"

Noob on the attack.

Glad you found my full name, I like it also

Damn, and your 37 lol.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nb0 &raquo;</TD></TR><TR><TD CLASS="quote">Someone told me that the best way to a firm pedal is a gravity bleed: open one bleed screw and letting the brake fluid drip out with out pumping the brake pedal, then close it up and move on to the next bleed screw. In addition never let the fluid go below the low mark on the MC. Has any one tried this technique?</TD></TR></TABLE>

I tried this a couple of times and it works well. What I usually do is give it a few pumps with the valve closed, 3 light pumps with the valve open (just to get the fluid going), and then gravity bleed. The only downside is that it takes longer than the traditional method.