Taking longer for car to stop after new brake pads and discs fitted

thebourke

I got new brake discs and brake pads fitting in my car yesterday.

Hoevever ,now it seems longer for the car to stop when i brake,is this normal?,

blackbox

You're supposed to break them in gently for the first 100km.

If they're as good after that, go back to the supplier.

sumo12

It will take a while for the new pads and discs to bed in - maybe 100km or more depending on the driving. Garage should have told you this

thebourke

so the brake stopping power should improve after 100km?

Spook_ie

If you haven't banjaxed them by heavy breaking already whilst bedding them in

windowcills

Pefectly normal, mechanic should have warned you

Nothing is pefect, so the brake pads calipers are not exacly parallel with the break disks

So one part of the break pad hits the disk first and this prevents other parts, this means that you have around 1/4 of the break working at first

only the parts that touch the disk will be worn, so they will be filed back quicky until the pad is perfectly flat and beds into the disk properly, alowing the full surface of the pad touch the disk

snowcat

You should address your driving style. Heavy braking especially in 100km would indicate you are driving too fast for road conditions or not anticipating hazards. Or you are travelling too close to vehicle in front. Brake wear is usually proportional to standard of driving.

eronayne

I would understand this to be the case if just the pads are replaced. If both pads and disks have been done with high quality parts I would expect the brakes to be as sharp as the day it was delivered from factory, no ?

mk7r

https://www.boards.ie/discussion/comment/120783860#Comment_120783860

No, brakes need to break in from the factory too

windowcills

https://www.boards.ie/discussion/comment/120783839#Comment_120783839

100km is a distance, there is no mention of time

Your thinking of 100km/hr (speed)

If it takes him 10 hours to do the 100km, he is a danger as he is driving slower then a cyclist

If i takes he 40mins then you have a very good point

Whatwicklow

They may need a bleed too, is your pedal sinking to the floor?

keithb93

It took my car around 2 weeks after changing the pads and disks to feel like braking power was back to normal. Some pads are covered with a resin the needs to burn off during use.

kirving

https://www.boards.ie/discussion/comment/120783839#Comment_120783839

There is nothing in the OP's description to suggest anything wrong with their driving.

@thebourke does the pedal feel soft or spongy, or does it feel hard, and just just aren't stopping as fast as before? If it is noticeably bad, go back asap.

Discs used to come with a film oil to prevent rust in the time period between manufacture and first used. The mechanic would need to clean this oil just before fitting, or it could be absorbed by the pads, which are then very difficult if not impossible to clean.

More commonly new discs are painted from the factory to prevent rust, and this paint if basically ground off when you first drive on them, but doesn't get absorbed by the pads (as oil would have). It may take a little time for it to be worn off and for your braking to return to normal.

thebourke

https://www.boards.ie/discussion/comment/120785664#Comment_120785664

The pedal is not sinking to the floor.

thebourke

https://www.boards.ie/discussion/comment/120786523#Comment_120786523

Its not hard but it just takes a bit longer to stop.I'm not speeding or braking hard.

greasepalm

Usually mechanic should road test car and do a pre bed in by gently applying brakes to slow down before handing the car back to you and advise no sudden or sharp braking to allow pads to bed in fully.

Its normal with new discs and pads until bed in and to give you more space to slow down and stop.