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Sign of a failing master cylinder?

someguy360

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Hi All,

Over the past couple of weeks I've been noticing my brakes aren't performing as well as they could be after 20-30km of driving.

I'm finding after going down an incline, the brakes aren't holding when I come to a stop, the car is slowly trying to creep forward.

I've bled fresh fluid through with no change, the brakes work fine around town when cold but as soon as I go on a decent drive I'm finding they just don't seem to be holding as much pressure as they should.

The master cylinder doesn't appear to be leaking but would this be a good indication of a failing cylinder or should I be looking elsewhere?

Cheers
 

stick3

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how old are the calipers and hoses, has it got abs and is the booster/mc still original another thing is the vacuum
 

someguy360

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how old are the calipers and hoses, has it got abs and is the booster/mc still original another thing is the vacuum

I'm going to take a good guess that everything is original from 94'
 

stick3

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I'm going to take a good guess that everything is original from 94'
you could you try replacing the booster /mc but if you plan on doing a front brake upgrade its about the same money to replace your old vr brakes and fit a vt-vy booster/mc i did this to my old 20 year brakes
 
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vc commodore

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I seriously doubt it'd be a booster issue.....The booster in my VC failed out of the blue and now my brake pedal is as hard as a rock....

Does the brake pedal start sinking, whilst you have pressure on it? That's a sign the master cylinder is starting to fail
 

someguy360

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The brake pedal doesn't feel like it's sinking, the brakes just don't want to hold.
 

woteva

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Crap pads and or glazed discs can do what you describe. Get your discs machined and use some quality brake pads.
 

deserthead

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My booster and MC went together. Booster had a leak, which caused a waayy harder pedal and random stalling issues (Vac leak).

MC was leaking in the back and was obviously leaking.

When did you last overhaul the calipers? Could be stuck/sticking slide pins, along with pads n calipers?
 
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