743power

I have an issue with brake firmness on my car. While the car is on, the brakes are not firm, no matter how much they are bled. After the car has been turned off and allowed to sit for an hour or two, the pedal becomes rock hard.

I recently replaced the prop valve, MC and BB, but the problem was around before those parts were replaced.

my brake setup is:

gsr brakes
rs booster/mc/ prop valve
goodridge stainless lines in the rear, OE rubber in the front


P.S. - Yes, I do know how to bleed brakes.

RTI

The pedal becomes hard probably because it looses vacuum. The same thing happens when you turn off your car and keep pressing the brake pedal.

743power

anybody have any input? I remember there is a way to tell if the mc, or bb is bad, I don't like troubleshooting brakes.

RTI

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 743power &raquo;</TD></TR><TR><TD CLASS="quote">I have an issue with brake firmness on my car. While the car is on, the brakes are not firm, no matter how much they are bled. After the car has been turned off and allowed to sit for an hour or two, the pedal becomes rock hard.

I recently replaced the prop valve, MC and BB, but the problem was around before those parts were replaced.

my brake setup is:

gsr brakes
rs booster/mc/ prop valve
goodridge stainless lines in the rear, OE rubber in the front


P.S. - Yes, I do know how to bleed brakes.</TD></TR></TABLE>


I don't think I understood your problem. I thought you were trying to compare the difference in brake pedal feel when the car is on or off. I assume you are complaining about your pedal being too soft. I didn't like the soft pedal feel either, so i increased the piston size of the MC. You already have an RS MC which I think is 15/16. Putting a 1 inch will help. Firmness and the distance the pedal needs to be depressed are two different things but will both reduce how soft the pedal feels. The elasticity of the system (including the fluid) will certainly cause the pedal to feel spongy. good brake fluid that is properly bled will help, along with metal brake lines insteadof rubber. The other thing to consider is that integra calipers have a bigger piston, requiring more fluid to operate. This affects how far the pedal is depressed which in turn may give you the impression the brakes are spongy.

If your problem is only the issue between the brake feel when the car is on and off, refer to my other post. In that case, there is probably nothing wrong with your brakes as every car behaves the same way when the BB loses vacuum.

743power

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RTI &raquo;</TD></TR><TR><TD CLASS="quote">


I don't think I understood your problem. I thought you were trying to compare the difference in brake pedal feel when the car is on or off. I assume you are complaining about your pedal being too soft. I didn't like the soft pedal feel either, so i increased the piston size of the MC. You already have an RS MC which I think is 15/16. Putting a 1 inch will help. Firmness and the distance the pedal needs to be depressed are two different things but will both reduce how soft the pedal feels. The elasticity of the system (including the fluid) will certainly cause the pedal to feel spongy. good brake fluid that is properly bled will help, along with metal brake lines insteadof rubber. The other thing to consider is that integra calipers have a bigger piston, requiring more fluid to operate. This affects how far the pedal is depressed which in turn may give you the impression the brakes are spongy.

If your problem is only the issue between the brake feel when the car is on and off, refer to my other post. In that case, there is probably nothing wrong with your brakes as every car behaves the same way when the BB loses vacuum.</TD></TR></TABLE>

I know how brake systems work, how to bleed them, how to modify them, how to install them, etc..

My brakes feel like stock cx brakes with no pads and boiled fluid. Every other civic with integra brakes I have been in or worked on feels like an integra. I have bled the brakes many times, properly.

The pedal doesnt do anything until about 1/2 way to the floor, and it is soft as hell the rest of the way there. When I turn the car off, the brake pedal gets so hard it is impossible to push. I've never been in a car where that happens, and I drive dozens of different cars every week for my job.

I figured there was some sort of correlation between the two things.

Last night I did all the checks outlined in the helms to check for bad bb/mc/ check valve and they all checked out alright.

q45mm

Not sure if you did this, but did you test the fluid?
Porbably would have already flushed it all out but figured might as well ask.