VX Loss of Brakes

[Bay 13]

Instead of throwing unnecessary money at it go to a brake specialist, Master cylinder would give you a engine light.
A problem with the brake master cylinder will cause the brake pedal to behave abnormally. All the pressure in the braking system is generated from the master cylinder. If it malfunctions, the cylinder will not distribute pressure properly, and the pedal will be affected.

When you continue using your car with a bad cylinder, it will wear out and start leaking. The pedal will also feel spongy, mushy, and may sink far down when pressed as you described.
I'ts your life and others you put at risk so do it right!!

 

[58Wayne]

Flush and replace your brake fluid. Its like engine oil, it wears out.

 

[vc commodore]

Instead of throwing unnecessary money at it go to a brake specialist, Master cylinder would give you a engine light.
A problem with the brake master cylinder will cause the brake pedal to behave abnormally. All the pressure in the braking system is generated from the master cylinder. If it malfunctions, the cylinder will not distribute pressure properly, and the pedal will be affected.

When you continue using your car with a bad cylinder, it will wear out and start leaking. The pedal will also feel spongy, mushy, and may sink far down when pressed as you described.
I'ts your life and others you put at risk so do it right!!

A failing master cylinder doesn't always give a warning....

Had a Mitsubishi light truck come in, which had a failing master.....The initial braking, wasn't an issue, but after 3 or 4 brake applications, the pedal started sinking...No warning came up on the dash....Just a sinking brake pedal....

Replaced the master and no problems after that.

I also had a master cylinder fail on my VC.....No warning on the dash.....Went to back out the driveway, touched the pedal and it went spongy.....Fortunately the car is a manual, so a slight pull up on the handbrake, with the clutch in and car stopped....

The symptoms described by the op are very similar to the Mitsubishi light truck that I dealt with

 

[Bay 13]

A failing master cylinder doesn't always give a warning....

Had a Mitsubishi light truck come in, which had a failing master.....The initial braking, wasn't an issue, but after 3 or 4 brake applications, the pedal started sinking...No warning came up on the dash....Just a sinking brake pedal....

Replaced the master and no problems after that.

I also had a master cylinder fail on my VC.....No warning on the dash.....Went to back out the driveway, touched the pedal and it went spongy.....Fortunately the car is a manual, so a slight pull up on the handbrake, with the clutch in and car stopped....

The symptoms described by the op are very similar to the Mitsubishi light truck that I dealt with

Funny that when they should work they don't and when you don't have a fault they pop up, lol. If its ABS and lose pressure you would think the ABS light will come on!!

 

[Bay 13]

Flush and replace your brake fluid. Its like engine oil, it wears out.

Nah the fluid just gets moisture as it cools and heats therefore gets contaminated which loses its pressure resistant. I be going to get it fixed if your not a handyman brakes are the most important part of a vehicle..

 

[vc commodore]

Funny that when they should work they don't and when you don't have a fault they pop up, lol. If its ABS and lose pressure you would think the ABS light will come on!!

Using this example, the OP should have had the same thing.....Spongy brake pedal, a light should have come on, but didn't

 

[ateram2000]

Stick3 and 58Wayne, thanks guys.

 

[stick3]

the brake warning light will illuminate when the reservoir is empty as the sensor is in the bottom where the wire connects

 

[mirrabucca]

IF your car has a brake fluid level warning system, you will get a warning when the fluid drops below a certain level. My VX - an S pak, doesn't have a fluid level warning or sensor.
All cars since the 1970's when dual circuit brakes became mandatory had a switch that detects a pressure difference between either of the dual circuits. Once the switch is "tripped" by a pressure difference, it stays tripped until reset. That is what drives the brake failure light.
In OP's case to get a brake failure light, only one of the circuits would have had to fail. If both circuits failed, then there's no pressure difference between circuits, so no light. The way to tell there's been a faliure of both circuits is that the car wont stop!
As to the OP's case, I'd say something screwy in the master cylinder. Maybe the rubbers have let go so the fluid worked its way past them. Anyway, not a job for a backyard mechanic. New MC would be my recommendation.

 

[ateram2000]

Apologies for a late update...
"The mechanic" found the master cylinder was "100%", so he flushed the lines
and bled them. Now brakes are 100%

What's more, he was not a rip-off artist. The brakes, plus replace a centre bearing
(which I bought, along with the brake fluid) cost me $150.