Drift4

iTrader: (12)

Did you need to replace your Brake Master Cylinder?

I think mine is needs to be replaced.

Replaced brake pads then proceeded to bleed brakes, 3 times using these methods. (NOTE: after installing the rear pads when I stepped on the brake pedal to let the pistons come out, I heard like a spring give. Now I do not know if that thing I heard is a seal that failed or a return spring / pin that gave.)

Also when bleeding the brakes, as soon as I open the nipple right before the pedal reached the floor, there is a noise emitted from the master cylinder like a groan.

1) Using Motive brake bleeder Right Rear / Left Front / Left Rear / Right Front
Got all bubbles out. Pedal travel was deep, slightly past throttle pedal.

2) Manually bled brakes In same order, 2 man method. I never let the fluid go
past 3/4 full on the resevoir. Still same result.

3) Manually Bled it doing the furthest from the master cylinder first. Same result

made sure that ABS was actuated to let any bubble escape.

Thanks

sponge bob

iTrader: (3)

Check your pedal assembly under the dash, there are springs and bearings down there maybe something has gone afoul. Generally master cylinders are pretty robust and just to blow apart all at once.

Drift4

iTrader: (12)

Thanks Sponge Bob, but yeah I checked it already, there is no spring in the pedal cluster for the brake pedal......I don't know what you are talking about bearings?...there are no bearings on the pedal cluster.

I am wondering if someone has an exploded picture of the master cylinder?

JTB

iTrader: (23)

This is a dumb question but it has to be asked. There are 2 nipples to bleed the brakes on each caliper -- the inside and the outside. You got both, correct?

sponge bob

iTrader: (3)

Once you button everything up and drive the car what symptoms are you experiencing? Does the car brake normally; I assume not as you keep trying to bleed them.

So has this popping/groaning sound continued since bleeding or are you still trying to bleed the brakes? Sorry if I’m asking simple suggestions bit I don’t know here you are at in the process.

Drift4

iTrader: (12)

LOL...yeah I did.....did the outside first then followed by the one inside.

Drift4

iTrader: (12)

The brakes have good bite, but the pedal travel is deeper and spongy, not like the firm pedal feel like when it was new / normal.

the pop sounded only once, the groaning is everytime you open the bleeder valve/nipple and when the pedal is just about to reach the floor is when you hear it.

Drift4

iTrader: (12)

no...no one has replaced there master cylinder??

Charlie_B

iTrader: (1)

Mine had the groan as well. Im pretty sure it is just the fluid rushing through some small hole when you open the bleeder screw.

Max Power

iTrader: (1)

Did you let the fluid level get low? Sometimes air can get into the master cylinder side and you have to take it off and bench bleed it. I think this may have happened to me because I'm having the same exact issues you are after my brake job.

Drift4

iTrader: (12)

you guys crack me up.....did you read #2 of the start of this thread:

2) Manually bled brakes In same order, 2 man method. I never let the fluid go
past 3/4 full on the resevoir. Still same result.

Can you please elaborate in this technique? So your saying air can get trapped in the master and not be able to be bled?...isn't that like installing a new one and bleediing it? I don't know where it would trap air while bleeding the entire brake system?

Max Power

iTrader: (1)

Sure I read it, but the symptoms sound like air trapped in the master cylinder. Scroll down a bit on this page or search for "master cylinder bench bleeding"

http://www.babcox.com/editorial/tr/tr502b.htm

Drift4

iTrader: (12)

But did you read the very first sentence?
"When replacing a master cylinder, be sure to bench bleed it before installing it in the vehicle"

I have not replaced my master cylinder yet...I have a brand spanking new one ready to go in. But thanks for the suggestion.

Max Power

iTrader: (1)

Sigh... I know what it is and when it's recommended. I also was trying to get a point across that air might have gotten in there and gotten trapped (which is why you bench bleed a new one in the first place). Just trying to give you a possible avenue for repair without replacing something that might not need it... no need to bold and underline things.

Drift4

iTrader: (12)

thanks point taken.........i have no other choice anymore than to replace the master.
but I will let you guys know what the outcome is, i will be replacing the master tomorrow, and i will definetly run fluid throught it....and do a complete re-flush along with the clutch.