G2hybrid

first off, the brake master cylinder was replace to fix the pedal sinking to floor.
the brake pedal is stiff now w/ pressure like it should be.
but the brake barely respond and the car rolls to a slow stop no matter how hard i press on the pedal.
I hear AIR HISSING near the brake pedal area when the engine is on and when the brake is applied.

Master cylinder, calipers replaced, and all brake lines have been bleed.

help????

bps2799

With the engine OFF, pump the brake pedal until it loses the boost and becomes very stiff, then, with your foot resting on the pedal, turn on the engine. The pedal should sink a little. If not, the booster is bad and the amount of force needed to stop the car will make it feel like the brakes don't work.

JimBlake

It could also be incorrect adjustment of the pushrod length.

When you replaced the MC, did you measure the length of it's pushrod? You have to compare to the old MC & they need to be the same. If they're not the same, there's a strange special measuring tool to help; then you adjust the length of the pushrod between the pedal & the booster. (The pushrod on the actual MC isn't adjustable.)

hondadude

When you replaced the master cylinder, WHY did you throw away the rubber seal that sits between the master cylinder and the booster? Bet you wish you'd have kept it now hmmmm?

bps2799

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hondadude &raquo;</TD></TR><TR><TD CLASS="quote">When you replaced the master cylinder, WHY did you throw away the rubber seal that sits between the master cylinder and the booster? Bet you wish you'd have kept it now hmmmm?</TD></TR></TABLE>

Service manuals more than pay for themselves by not having to correct expletive-ups like that.