RxVertJames

Exactly what happens when the brake master cyl. starts going bad? I have an 88 vert and I'm thinking that the master cylinder is going bad, but not sure. My front brakes (mostly drivers side) keeps making this creaking noise, and now both front brakes are making this noise. It almost sounds like it's in the suspension, but the car handles and drives fine. If I stop real hard, the noise sounds like I'm going to break somthing in my front end, but nothing ever does. also, the pedal does feel like its not right, and it feels like the brakes can barely lock up.. just in case as well, how much does a brake master cyl. cost usually.. thanks guys!

Don49

iTrader: (3)

Did you check your front brake pads? A master cylinder going bad won't make the noises you are describing. A bad master will either give you a spongy pedal or a pedal that slowly drops to the floor if you hold it down. Also it would probably show signs of leakage ( low brake fluid in resevoir).

clokker

iTrader: (2)

First thing I'd do is pull the front calipers and verify that the piston(s) isn't frozen.

If you have the base model (single piston) caliper, clean/lube the pins that the caliper slides on.
If you have the four piston units, check that all four pistons are functional.
Check pads for uneven wear (either side to side or front to back).

RxVertJames

sorry I didn't mention this, but both calipers (4 piston) are rebuilds from advance auto, and I've replaced the driver side a couple of times under warranty. I'll check out what you mention, but if it isn't that, then I'm going to try to get a new or rebuilt Master Cyl.

clokker

iTrader: (2)

Even with that new information your logic escapes me.

Since the noise ("creaking") is coming from the front of the car, why aren't you concentrating on the front of the car?
A bad MC will do lots of things but I've never encountered one that makes "sounds like I'm going to break somthing in my front end".

For some reason you have dismissed the suspension as the culprit and fixated on the MC- I can't imagine why.

RxVertJames

Well.. 2 things. 1. noise is coming from brakes if I pump at a standstill. 2. searched and fc3stech says his did the same thing.. I am listening to your advice clokker I've read a bunch of your threads and your advice is good, I'm not trying to ignore anything. if its the suspension, I'll fix/replace it. I'm just trying to get help knowing whats wrong and make sure of whats wrong, not to get flamed.

clokker

iTrader: (2)

Sorry, didn't mean to be obnoxious.

Look at it this way...if you press the brake pedal and get noise from the front end that would mean that the MC is actually doing it's job (applying hydraulic pressure to the calipers).
Something else up there is the problem.
Maybe wheel bearings?

Anyway, it's worth a lot more investigation before investing in a new MC...they are expensive (@$150) and a PITA to replace/rebleed.
It'd be a shame to swap the MC out and still have the problem, no?

Tell you what- try this...
Remove the calipers (both sides) and hang them from the strut with a coat hanger.
Get a piece of wood approximately the same thickness as the rotor and put some in each caliper between the pads.
Now, depress the brake pedal.

If you still get the noise, something is going on with the caliper.
If not, that means that the brake pressure is flexing/stressing something that the rotor is affixed to.

Sound logical?

fc3s-infini

Same thing was happening to me recently. (s5 turbo).
Changed the brake pads and flushed the brake fluid, creaking is no longer there!