Aygo Brakes

[Bert2012]

A plea for my sanity - really need to understand if I'm being neurotic or actually sane.

Had my first Aygo from new (10 registered) and after about 18 months noticed something odd when braking sharply. Best way I can describe is it felt 'gritty' , sometimes making a crunching sound and took a moment before the brakes felt like they'd actually kicked in. After some time being the only one to notice this my husband started to also. In the end we queried as part of its 2 year service. We were told there was nothing wrong with them but because we persisted they agreed to 'deglaze' them. Didn't work and problem continued.

This was a lease car and was returned after three years. We now have another Aygo (08 registered) and the brakes are doing exactly the same thing. I can't believe this is a coincidence. So either it's a normal thing for all Aygo's to have brakes that feel dodgy and I'm being neurotic, or there is a commonly experienced fault and I'm totally sane.

Any thoughts?

[Cyker]

If it's kind of a going-over-gravel sort of feeling, it's probably just the ABS kicking in and is nothing to worry about (Although you might want to tweak the driving style to brake earlier and gentler :D).

If you're getting this when you're braking hard enough to throw yourself forwards, then it's almost certainly just the ABS.

The Yaris and Aygo have very strong brakes but because they weigh so little, I found the ABS tends to get a bit more of a workout than on other heavier cars to stop them skidding. It's not so bad with new brakes, but once they've worn in I guess the braking force is higher and the ABS has to cut in to stop the wheels locking up when braking heavily.

If you're getting this under merely firm braking (As opposed to heavy or emergency stop braking!) then I'd get it checked as there might be some scoring on the discs or pads which is preventing one side applying full braking force.

Also, if the disc face only has a narrow band of polished braking area and has more than a cm of untouched disc above and/or below, then the brake pads are not doing their job and need to be checked/replaced.

[FROSTYBALLS]

Hello Bethan - welcome to Toyota Owners Club.

Topic moved to the Aygo club

[Raistlin]

Hi, Welcome to the club... Enjoy

It could be how you brake that is causing the pads to glaze, heavier and later braking can cause this.

Leave a bit more space and brake slower ( except in emergencies obviously ) it's the heat build up on the pads that cause this.

Hard revving and hard braking ( Boy racer style ) will do this to the pads all the time.

[Wiz201]

I've just got a 2014 Aygo and I'm having to be gentle on the brakes anyway as I run them in, but Aygo and Yaris brakes are quite efficient so they don't suit drivers with a heavy foot, they need gentle braking. My way of braking is to actually take my foot off the accelerator pedal and do gentle pushes on the brake until I get up to the white line of a junction etc or the vehicle in front of me then I keep steady pressure on.

[Wiz201]

Would like to add I have not felt the ABS act once with the Aygo using my above method.

[rajivrattna]

Aygo brakes are not power assisted and therefore are not sudden.They are more progressive and if travelling fast and braking hard (on high way for example) they tend to be sluggish but for city driving they are fine. They remind me of my toyota corolla from 1992 that had no power assist. My other car, BMW has a power assist and killer brakes that almost throws you out of the car if not careful! If there is a grit trapped between the brake pads and the disc, it produces uneven braking and makes a lot of screeching noise. Worth checking and dislodging the grit if that is your problem

[Raistlin]

Bethan was complaining about glazing...

[rajivrattna]

Looks like we connected to different parts of the original post from Bert2012. I hitched on to this part of the post and replied accordingly,

"noticed something odd when braking sharply. Best way I can describe is it felt 'gritty' , sometimes making a crunching sound and took a moment before the brakes felt like they'd actually kicked in"

Perhaps it was my sub conscious self that being disappointed with Aygo not having a brake assist that kicked in here. My Bad!

[Cyker]

Hi, Welcome to the club... Enjoy

It could be how you brake that is causing the pads to glaze, heavier and later braking can cause this.

Leave a bit more space and brake slower ( except in emergencies obviously ) it's the heat build up on the pads that cause this.

Hard revving and hard braking ( Boy racer style ) will do this to the pads all the time.

Is that right? I thought glazing was caused by long gentle braking, e.g. when going down a hill and using the brakes to maintain speed rather than downshifting.

I'm sure last time I saw a thread on this, the proposed fix was to brake hard a few times to 'break' the glaze...?

Still, glazing doesn't usually cause a 'gritty' feeling, just makes the brakes feel spongy and unresponsive.

[Raistlin]

What are glazed pads?

When brake pad compounds are overheated, the components crystallize on the surface as the resins and binders begin to melt and break down.

This crystallized surface has a lower friction coefficient that simply means it cannot grab the surface of the rotor with the same amount of force as the undamaged pad.

The term glazed is used because the pad surface will look smooth, shiny, and metallic like a glazed ceramic tile.

Once a pad has been glazed, it cannot be repaired and it needs to be replaced.

Glazing is caused by overheating the brakes beyond the operating temperature designed for the pad and/or failure to follow the bed-in procedure for the pads.

It can also be caused by overheating the brakes in either mountainous terrain or 'racing' between stop lights (running at high speed right up to the stop light/sign and then braking quickly = POOR DRIVING HABITS).

This type of damage is not a defect in the pad and is not covered under the manufacturer warranty.