Brake Pedal too Soft

**Animal15** · 30-12-2011, 08:34 PM

Car : AE86 with Disc Breaks (OEM).

Finally car's on road; But got problem with brakes....
Brake pedal is too soft when i step on the pedal half way through no breaks after that it bites like hell.

Bled them few times no air at all.

I'm running 272 cams with ITbs also using Eagle Vacuum box no idle Control Valve.
When engine is turn off pedal is nice and Firm but when it's running really soft.

Is it the Vacuum causing this or common with ITBs ?

**dumbass** · 30-12-2011, 08:42 PM

u got one way valve on the hose from vacuum box to booster
it should suck from booster to box
u shoudl nto be able to blow air into booster

**litldv8** · 31-12-2011, 09:23 AM

discs or drums on the rear?

**Animal15** · 31-12-2011, 06:05 PM

both discs ; i think it may be the one way valve cause i didn't put one.

**lexsmaz** · 31-12-2011, 10:13 PM

If the pedal changes when its running, especially if the pedal height drops & the pedal feels softer the Brake booster is working as its giving you assistence to the pedal effort that you are applying .. ( The assistence of the brake booster can help show up problem's if there is any in the system as its applying a lot more force to the Brake master than just your foot pressure alone can apply, eg, some faults, not bled properly, pads not fitting properly, etc, etc ..

Did you do anything to the brakes when it was off the road, take any brake parts off ? fit new pads, etc, etc ? ...

**Animal15** · 19-01-2012, 11:35 PM

Put Check Valve ( one way valve); But still the same , Pedal is too Touchy.... MAy be the MC??

**CrUZida** · 24-01-2012, 06:56 PM

Have you bled the MC?
Same as bleeding the calipers, just crack each line separately when someone is hard on the pedal. You'll spill brake fluid though, so have lots of rags on hand.