beingblueeyes

Ive been lurking here for a bit and have learned a lot but i really need help with a problem I'm having with my 01 accord (v6 w/ABS). Ive replaced the rear rotors and pads, both the steel brake lines going to the rear (made sure they are not leaking) and the master cylinder (bench bleed). after bleeding the brakes for over 3 hours in the honda recommended fashion (LF/RF/RR/LR) im not getting any air out of any of the brake calipers. now with the car not running the brake pedal is a hard as a rock but as soon as you start the car the brake pedal gos 1/2 down with little effort then gets harder but you still can push the pedal to the floor. whats the likely hood that the new master cylinder i got being bad? has anyone run into this problem before?

please help im at my limit with the car

nus_dogg

Keep bleeding the air out of the MC then re-bleed the system.

My co-worker had the same problem going on with a customer's Saturn S Series car. He said there's a bunch of air inside the MC that he had to bled out then re-bleed the calipers which got the brake pedal to pressure up to normal again.

beingblueeyes

Thanks dogg ill give anything a try again at this point

beingblueeyes

re-bench bleed the master cylinder this morning using 1/4 tube for 45 min then bleed each wheel unit i got 310 ml of dot 3 out. problem still remains any other idea's?

would i need to cycle the abs pump?

beingblueeyes

a little update: after taking a brake from the car, i went back to it pump the brakes 2 times got a solid pedal keeping my foot steady then started the car, the pedal went right to the floor (wouldn't that rule out the master cylinder?). turned off the car drank a beer (12oz) then unplugged the vac source from the brake booster and it still had vac. ill try gravity bleeding it tomorrow.

i looked into trying to cycle the ABS but i couldn't find a relay for it so i put all 4 wheels back on it and test drove it around the block getting up to 40-45 and doing emergency stops trying to get the ABS to cycle but no joy

Tesla220

You could have a stuck caliper slide. The pedal dropping to the lower position is normal if you pump it up before you start the car then start the car. This just means your brake booster IS working. Check all 8 caliper slides.

beingblueeyes

checked all 8 slides and there fine. I am replacing the master cylinder again, its the only thing i can think of