braking issue. inconsistent pedal feel, etc.

[Geezy]

BRAKE UPGRADES:

-Z32 calipers front and rear
-Z32 1 1/16 master
-stainless lines all around
-hawk pads all around
-drilled/slotted rotors

ISSUES:

i've had this set up for 3 years now. never had a problem until recently.
been starting to get inconsistent brake pedal feel.
50% of the time the travel is short and the pedal is stiff.
the other 50% my asshole puckers when the travel increases and i get that "soft" feeling. and i have to give it another pump or two to maintain braking.

another issue is during right turns ONLY, i hear a grinding sound which sounds like maybe the pad isn't seated onto the rotor. (similar to the sound of when you lift your car and spin your wheels and the rotor rides the pad, but much louder) *thats the best description i can give.

WHAT I'VE DONE SO FAR:

bled the whole system including a full fluid flush and fill. which helped for a little while, then the problem came back.

ive checked for leaks at the master and all the lines. though i have yet to pull the calipers off and thoroughly check for leaking seals, i have yet to find moisture in that area or any leaks at all.

the pads are seated fine against the rotors and have no "play" or gaps in between... (so i dont know where that grinding is coming from)

as far as i know, nothing is warped, as i do not any get any vibration under braking.

[KiLLeR2001]

ISSUES:

i've had this set up for 3 years now. never had a problem until recently.
been starting to get inconsistent brake pedal feel.
50% of the time the travel is short and the pedal is stiff.
the other 50% my asshole puckers when the travel increases and i get that "soft" feeling. and i have to give it another pump or two to maintain braking.



Most likely you need a new master cylinder. My old one didn't leak or anything but one day when bleeding it, my friend noticed when I was pushing the brake down hard to build pressure it was shooting back into the reservoir. Could also be the sign of the brake booster failing.



another issue is during right turns ONLY, i hear a grinding sound which sounds like maybe the pad isn't seated onto the rotor. (similar to the sound of when you lift your car and spin your wheels and the rotor rides the pad, but much louder) *thats the best description i can give.



This is usually a wheel bearing issue. If you turn to the right and you hear it, it's your left side wheel bearing. Always a good practice to replace them both however.

[Geezy]

Most likely you need a new master cylinder. My old one didn't leak or anything but one day when bleeding it, my friend noticed when I was pushing the brake down hard to build pressure it was shooting back into the reservoir. Could also be the sign of the brake booster failing.


hmmm... yeah. i was doing some research and ive read on some occasions of this happening. i'll try to come up with a test for the booster... what do i need to look for when pumping the brake and watching the master??


This is usually a wheel bearing issue. If you turn to the right and you hear it, it's your left side wheel bearing. Always a good practice to replace them both however.

yeah i do hear the grinding coming from the left side.... ugh. guess its about that time. i'll take it to the guys at car quest. they got a machine shop and they're usually pretty reliable when it comes to pressing in bearings like this.

thanks man. pointing me in the right direction.

[KiLLeR2001]

hmmm... yeah. i was doing some research and ive read on some occasions of this happening. i'll try to come up with a test for the booster... what do i need to look for when pumping the brake and watching the master??


Take your master cylinder top off and have someone pump the brakes. Watch for a stream of fluid everytime the pedal is depressed. There should be very little movement but if you can clearly see fluid (and hear it) swishing around, it's a bad master.

[Geezy]

so i had someone pump the brake and i watched the fluid in the master. i can see it move, but not a "stream" of what you're saying.

i also tested the check valve to the booster. works fine.

im gonna take a mighty vac to the booster and see if that is holding vacuum.

otherwise.... im at a loss right now...

[Geezy]

just tested the booster. holds vacuum fine...

[Geezy]

found the suspected problem.

was checking all the hubs... and my rear driver had play in it...

turns out im missing 2 bolts and the other 2 were loose...

the play was causing the piston to not seat properly causing the awkward pedal feel and the grinding noise during right turns.