Partial brake failure!

[Codswallop]

Had one of those Monaro surprise and delight problems today - pressed the brake pedal coming up to a roundabout and had minimal braking power. A message popped up at the same time on the LCD display saying "brake failure" (just in case hadn't already realised).

There was an accompanying speed related scraping sound from the wheel area.

When I came off the roundabout I applied the brakes and the car stopped as normal and the brake failure warning message disappeared!? Checked the car over by the roadside which seemed fine, and gingerly drove the remaining couple of miles home. At home I took the wheels off and discs and pads all look fine. Brake fluid level normal.

What the hell happened!?

[snowwolf]

Is that not the normal braking on a Monaro joking aside the only thing I can think of is the vacuum assist part of the braking system but why it should fail on one occasion is beyond me.

[mik_ok]

Yep - sounds like it could be servo. If you have a leak in the vacuum line to the servo it can fell perfectly normal under normal braking, but you lose all assistance when you ask for more than the (compromised) system can deliver.

[Behold81]

Are you supercharged???

[L2VXR]

Have you had a proper look at the pads ie the rear pad on each disc, from your description it sound exactly the same as what happened to the wifes mazda when the pad material came away from the backing (scrapping noise) then when the peddle is pressed again the slack in the hydraulics is taken up (brake faliure) then normal service resumes albeit with metal to metal contact on the back of the disc.

[Codswallop]

L2VXR said:

Have you had a proper look at the pads ie the rear pad on each disc, from your description it sound exactly the same as what happened to the wifes mazda when the pad material came away from the backing (scrapping noise) then when the peddle is pressed again the slack in the hydraulics is taken up (brake faliure) then normal service resumes albeit with metal to metal contact on the back of the disc.

Had a look at pads on both sides and all looked fine with plenty of meat on the pads. Am away for work this week so will get the car checked over by my garage next weekend and report back when I find out what the problem was.

[Codswallop]

snowwolf said:

Is that not the normal braking on a Monaro?

It was even worse than usual

Behold81 said:

Are you supercharged???

Sadly not. I can see the logic behind your question though - if the car had been supercharged the extra weight over the front wheels would help the tires dig into the road under heavy braking

[Behold81]

Ha ha ha.

My logic was the charger boosting in to your servo.

But I like the safety feature you have pointed out.

Codswallop said:

Sadly not. I can see the logic behind your question though - if the car had been supercharged the extra weight over the front wheels would help the tires dig into the road under heavy braking

[Codswallop]

Just to update on this - turned out the rear nearside brake pad material failed. A piece of pad material had come away which interferred with the braking initially, and then when that piece fell away normal(ish) braking resumed but with a dose of the scraping noise.

Left a nasty gouge on the disc though, so time for new discs and pads on the rear axle, and all sorted

[THUNDER STORM]

Codswallop said:

Just to update on this - turned out the rear nearside brake pad material failed. A piece of pad material had come away which interferred with the braking initially, and then when that piece fell away normal(ish) braking resumed but with a dose of the scraping noise.

Left a nasty gouge on the disc though, so time for new discs and pads on the rear axle, and all sorted

What brake pads were you using?

Ade

[Codswallop]

Don't know what pads were on the rear - they were on the car when I bought it.

I wouldn't be surprised if the pad failure was age related given the low mileages the car did in the years prior to my ownership, so they had probably been on the car for a while.

[VinceM]

Glad you got it sorted mate.