Using the brake pedal at traffic lights?

fivetide

Lum wrote: »

Touching the disc, yes. Pressed hard against the disc, no?


Almillar: If you're going to be pedantic, you don't wear out a bulb by leaving it on, on off cycles are what wear bulbs out, so it could be argued that sitting with the brakes on means one less off/on cycle.

Almillar & lum,

Surely no wear is takign place though? Just because it is being pushed no actual movement is goign on. Once movement has ceased then so has wear. To that end, touching, with whatever pressure will have the same result.

It's why pads will rust to discs and leave an outline if the weather has been bad and the vehicle not moved for a few days.

5t.

Lum

It's the combination of heat and pressure that causes the transfer of pad material.

The issue with rusty brake discs is a separate process. The discs rust because they're bare metal being exposed to moist air. The part of the disc that is in contact with the pad is not exposed to moist air and so doesn't rust, or at least doesn't rust at the same rate.

A few good hard braking cycles and all the rust is scraped off.

fivetide

Hmmm. I hear you but still not totally convinced. Again, as the pads are already in contact with the disc then no air is getting round and the calipers etc would help dissipate the heat.

I have to say that I've never had any feeling of warping after holding a car on the brakes even on older cars with less sensible set ups.

Can't help feelign it's a bit of an urban myth.

5t.

Lum

It's not guaranteed to happen, it's a worst case scenario.

Best way to make it happen is to go for an enthusiastic drive on a long twisty little B road which should see lots of braking and get your braking system nice and hot. Then immediately proceed to the nearest traffic light and sit there with your foot planted hard on the brakes.

If you're holding it on the brakes at the end of a motorway sliproad and have previously been doing 70 with no braking other than the deceleration on the sliproad, it's unlikely to happen. Likewise if you've been in stop start town traffic and haven't been driving like an idiot, e.g. hard acceleration and late, hard, braking then again it's unlikely to happen.

The advice not to sit with the foot on the brakes still stands though, as one day you will do it and your brakes will have gotten hot for some reason, and brake discs are expensive.

I learned this the hard way when I used to have a Subaru Legacy twin-turbo with an automatic gearbox. That thing used to love eating front brake discs until I got into the habit of using the handbrake instead.

w211

fivetide wrote: »

Also, some manufacturers, well one I know of, MB say there is no need to even take the car out of drive whilst waiting at lights. I think some models even have a 'hold' feature to stop that autobox creep when in D and idling.

That is correct, however, that "hold" function will still leave the rear brake lights on. As leaving the brakes on, there's a possibility that the discs won't cool down and if they are overheating a warning message will come on the display.

wantonnoodle

Strider590 wrote: »

I know the rule, I looked it up, but as it no longer refers to just traffic light controlled junctions, it was pointless posting it.
And when I learnt to drive, there was only the one option, the one that nobody ever uses.

I wish that people would learn to turn right offside to offside again. There is a junction by my mum and dads which, unless you turn offside to offside, is a nightmare. You really can tell when someone has positioned themselves for a nearside-nearside turn as the traffic backs up as there is no room for people going straight on to get past.

Everytime I use the junction it makes my blood boil. And it doesn't help when other people say that it is not used any more.

Riccal

StrangelyBrown wrote: »

That must be very old then because I learnt over a decade ago and it gave 2 options (offside-offside or nearside-nearside).

'going round the back' of the vehicle (nearside or right side) is considered safer because your view of the oncoming traffic isn't blocked but yet it rarely happens.

It's Rule 181 if you need a refresher :-)

going round the back of the vehicle would be right side to right side which is off side to off side not near side.

Riccal

wolfehouse

i was taught that if you are driving an automatic you should hold your foot on the brake
at the lights as automatics have a forward creep when at a standstill
that you don't get with a manual.

callistris

People sat in queues of traffic with their foot brake applied winds me right up, as I find the lights as glaring as headlights as some are really bright.

To deal with it I just flip down my sun visor, as you can tell when the traffic is moving as the bright red glare stops:)

Ages ago while stuck behind someone at some temp traffic lights for ages, who had their brake lights on I jumped out and asked the driver to apply their handbrake as the brake lights were really bright and dazzling. The driver replied, "it is on" Then take your effing foot off the brake pedal then:mad:

callistris

wolfehouse wrote: »

i was taught that if you are driving an automatic you should hold your foot on the brake
at the lights as automatics have a forward creep when at a standstill
that you don't get with a manual.

I commented ages ago on this forum about this subject of rear brake lights, and was given this as an excuse/reason.

All I can say is there must be a hell of alot of automatics on the road:rotfl: