I did a search on specifically in the brakes forum on HondaTech and so far it seems to be a common problem on the Honda Del Sol SI's. But most people manage to solve the problem, but not me . It's already been two weeks already =.=*

First I'll lay out the setup, then followed up with the symptoms.

-NEW Front and Rear Calipers
-Front Powerslot rotors (less than a year old)
-Rear Blank rotors (less than a year old)
-SS brake lines front and rear.
-Hawk HPS pads front and rear with plenty of life on them
-NEW Brake master cylinder


And now the following symptoms.
-When the car is off, brake pedal becomes stiff when being pressed down at least 3 times
-When the car is started, brake pedal sinks to the floor and has a spongy feeling.
-With above being said the brakes don't even grab properly.


What was being done to resolve the problem which is still present.

-Change the front and rear calipers to new ones
-Change the rubber brake lines to SS
-Gone through 2 NEW brake master cylinders
-Tried assorted methods of bleeding the system, including a machine to bleed the brake fluid


What combination we used to resolve the problem which is still present.

-change calipers back to stock but kept SS brake lines, brake pedal is still spongy
-change calipers back to stock and rubber brake lines which made the pedal feel worse
-change everything back to original and same results are still present.

__________________________________________________ _______________


With all this being said, I don't even have a clue on what the problem is now. Last thing I could possibly suspect is the Brake Booster.


If anyone has insight on this problem, please feel free to post. It's becoming frustrating.

 

let's go through the process of elimination:

it could be possible that you might still have air in your lines (especially since you serviced all four corners and a m/c). but according to your post, it seems like you have bled the system several times already. curiously, did you bench bleed your m/c? another common problem is letting the master cylinder go empty during the bleeding process. if this happened you need to start over with the bench bleeding. since you stated that you've bled the system several times (using different methods), i'm guessing the fluid is coming out pure (no air)

two things that cause a soft brake pedal - air in the lines or a leak. the leak will cause brake fluid to leak on the ground. if there is air in the system you can generally pump the system up and hold pressure but the pedal is soft when it is first applied. the third cause which can be an internal leak in the master cylinder but this is fairly rare in a new cylinder.

i doubt its your booster, if it went bad, it would feel stiff (like it won't hit the floor), like you're doing leg presses @ the gym. you can test this by pulling the vacuum line connected to your booster (with the engine off) & it'll hard to push (demonstrates what a bad booster feels like). reconnect it with the engine on, you'll feel your pedal & idle go back to normal (good booster w/ normal pedal effort).


did you remove (replace or re-use) the old rubber ring seal (between the booster & the m/c)?

did you adjust the pushrod on the m/c?
click the link below...i think it's relevant & pertains to the problems you have described.

http://www.tegger.com/hondafaq/maste...djustment.html