Brake Pedal doesn't hold ... Master Cylinder issue?

[Dar]

G'day guys,

The brake pedal isn't holding. I'm assuming it's the Brake Master Cylinder as there are no leaks anywhere. Is there a way to repair it without having to fork out the $400 to buy one? Also heard that I shouldn't buy a second hand one as the seals may have dried out and you can't tell as it's a sealed unit.

ANY advice would be realy appreciated.

Cheers,

Darren

I drive a Nissan Patrol 2012 GU 3.0 Diesel with ABS

[PeeBee]

The master cylinder itself is pretty simple, spool and a couple of o'rings and spring, but the ABS is another matter. I wouldn't stuff with it unless 100% certain of what you are doing - perhaps best left to a brake expert.

[mudski]

When you say its not holding. Exactly what do you mean? The Patrol wont stop when the brakes are applied? The pedal slowly sinks to the floor whilst stationary?

[10G]

The bloody things don't stop anyway, even when you're brakes are 100%, well mine doesn't.

I thought I had a crappy master cylinder at around 80,000ks. The pedal would just sink to the floor if I kept pressure on the pedal, never got a hard pedal. Got it replaced with a brand new one, exactly the same thing happened, I gave up.

I'm in the habit of pumping the pedal before braking now.

So what you're experiencing may be normal????

[mudski]

The bloody things don't stop anyway, even when you're brakes are 100%, well mine doesn't.

I thought I had a crappy master cylinder at around 80,000ks. The pedal would just sink to the floor if I kept pressure on the pedal, never got a hard pedal. Got it replaced with a brand new one, exactly the same thing happened, I gave up.

I'm in the habit of pumping the pedal before braking now.

So what you're experiencing may be normal????

Should have replaced the M/cyl with the 4.8L one. Sligthly bigger bore size. I upgraded the calipers, rotors and m/cyl to 4.8 spec, also fitted braided lines and now it stops too good. Dangerous in the wet. It need ABS now....

[geoffayres]

Should have replaced the M/cyl with the 4.8L one. Sligthly bigger bore size. I upgraded the calipers, rotors and m/cyl to 4.8 spec, also fitted braided lines and now it stops too good. Dangerous in the wet. It need ABS now....

A good move.....

[MB]

G'day guys,

The brake pedal isn't holding. I'm assuming it's the Brake Master Cylinder as there are no leaks anywhere. Is there a way to repair it without having to fork out the $400 to buy one? Also heard that I shouldn't buy a second hand one as the seals may have dried out and you can't tell as it's a sealed unit.

ANY advice would be realy appreciated.

Cheers,

Darren

I drive a Nissan Patrol 2012 GU 3.0 Diesel with ABS

G’day Dar mate!
Just spent quite a few well worth dollars too on bringing Mrs MB’s GU brakes back to original specifications, pedal feels great again for a 3,000kg truck
Are running some great 4.8L later model/variant stuff too on my old paddock diesel ute but unsure if that meets insurance quirky stock needs?



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