Hydrolic Disk Breaks = Un happy Bank Manager

woodyonthebeach

took the mountain bike into the LBS yesterday to have the breaks looked at after a particularly hard thrashing in the lakes Damage report

Break Pads Cooked - Even the LBS were surprised by the state of them
Fluid Degraded
Disk Cooked
Pistons jammed

Work Carried out

Break levers stripped
Break callipers striped

New Pistons
New Pads
New Oil
Potentially new Disk as well

Wont be able to condone using the train for a long time now after all this work that has just been done. Might purchase some slicks and turn it into the commuter for a bit.

Kieran_Burns

This is why I always rant at people who say you should keep your foot on the brake when at a standstill. (in a car) Supposedly to increase visibility to the rear.

NO!!!!!!

You cook the brakes, warp the disks, boil the hydraulic fluid and generally wreck everything.

Golden rule: LET THEM COOL DOWN.

daniel_b

Kieran_Burns wrote:

This is why I always rant at people who say you should keep your foot on the brake when at a standstill. (in a car) Supposedly to increase visibility to the rear.

NO!!!!!!

Do what..........?

Those people who say that, do they have those funny white coats on where there arms are secured via velcro........?

Dan

woodyonthebeach

Kieran_Burns wrote:

Golden rule: LET THEM COOL DOWN.

They didnt have chance was coming the side valley at Coniston Water. Had to hit the anchors hard or the next stop would be tour bus or big lake didn't fancy neither

At least they have lots of lube in the LBS to make it less painful

Kieran_Burns

We had a "Company Driver Education Program" a couple of years back, which you had to pass to keep driving company vehicles / pool cars.

I had a 'difference of opinion' with this jobsworthtosspot who told people that when braking to join the rear of a standing line of traffic you should keep your foot on the brake pedal to ensure that the brake lights maximise your visibility to any other cars approaching from the rear.

I explained the above to him and he simply refused to accept that such a thing happens - so we had that difference of opinion.

The other one was that I thought he was a semi-educated, blinkered cretin with no independent though processes and the inability to question information given to him simply because he was told it first; and he.... didn't know what I was talking about.


Anyway back to the OP.... I read that you should alternate between front and rear braking or be braver on descents to minimise damage to the brakes

woodyonthebeach

Kieran_Burns wrote:

Anyway back to the OP.... I read that you should alternate between front and rear braking or be braver on descents to minimise damage to the brakes

I did try i was brave until the last 150m or so then my shorts went brown and had this tingling sensation up my spine then smelt burning

i did try alternating between front and rear even the breaks on mates Yeti were glowing and there bigger than mine.

camerone

Kieran_Burns wrote:

This is why I always rant at people who say you should keep your foot on the brake when at a standstill. (in a car) Supposedly to increase visibility to the rear.

NO!!!!!!

You cook the brakes, warp the disks, boil the hydraulic fluid and generally wreck everything.

Golden rule: LET THEM COOL DOWN.

hold on. how does having the brake on a stationary car cook the brakes? surely if the pad and the disc are static there is no heat? warp the discs? i have an automatic car, always have brake on when stationary and have not needed new discs in 60000 miles so far. are you driving a morris oxford?

CiB

Kieran_Burns wrote:

We had a "Company Driver Education Program" a couple of years back, which you had to pass to keep driving company vehicles / pool cars.

I had a 'difference of opinion' with this jobsworthtosspot who told people that when braking to join the rear of a standing line of traffic you should keep your foot on the brake pedal to ensure that the brake lights maximise your visibility to any other cars approaching from the rear.

I explained the above to him and he simply refused to accept that such a thing happens - so we had that difference of opinion.

The other one was that I thought he was a semi-educated, blinkered cretin with no independent though processes and the inability to question information given to him simply because he was told it first; and he.... didn't know what I was talking about.


Anyway back to the OP.... I read that you should alternate between front and rear braking or be braver on descents to minimise damage to the brakes

I'm with you on this. The correct advice is to hold the car on the handbrake, because if you are rear-ended and your foot slips off the brake pedal there's more chance of the car in front being shunted too. Keep an eye on what's happening behind and be ready to apply the foot brake momentarily if necessary to warn approaching traffic that you are stationary. Sitting in a queue of traffic with the foot brake on dazzles the driver behind, and is as bad as those numpty half-wits who drive in busy traffic with rear fog lights on. Rear fogs are no different to main beam in some respects; they dazzle and aren't necessary if someone is behind as he or she is aware of your presence by now. Switch them off when someone is behind - brake lights and fog lights. Grumble grumble.

Can I point out that the hydraulic disc brakes have caused the OP some angst. No? What the heck. Break = broken. Brake = stopping facility. I'll be off now.

Aidy

camerone wrote:

hold on. how does having the brake on a stationary car cook the brakes? surely if the pad and the disc are static there is no heat? warp the discs? i have an automatic car, always have brake on when stationary and have not needed new discs in 60000 miles so far. are you driving a morris oxford?

I'm unconvinced that it will "cook the brakes". The discs, having a larger surface area/volume ratio will cool down faster than the callipers.

Warping callipers might happen - keeping part of the disc pinned whilst it's cooling down could lead to some interesting effects.

But in any case, the initial movement of a brake pedal just activates the brake lights. You could keep the brake lights on without actually applying the brakes.

CiB

camerone wrote:

hold on. how does having the brake on a stationary car cook the brakes? surely if the pad and the disc are static there is no heat? warp the discs? i have an automatic car, always have brake on when stationary and have not needed new discs in 60000 miles so far. are you driving a morris oxford?

Because the hot pads dissipate their residual heat into one area of the discs in a short space of time, which can cause it to warp. It's a very well known issue.

Ps - I'd hate to be the bloke behind you on a journey, having to sit behind a pair of brake lights at every set of lights. Try using the handbrake; have some awareness of what other motorists behind you are seeing when you sit with your foot on the brake at junctions & traffic lights.

DevUK

camerone wrote:

hold on. how does having the brake on a stationary car cook the brakes? surely if the pad and the disc are static there is no heat? warp the discs? i have an automatic car, always have brake on when stationary and have not needed new discs in 60000 miles so far. are you driving a morris oxford?

Yes, but you'll have used them to stop though, so they'll already be hot. I can understand what Kieran is saying. When you've got heat into the discs you're then sitting with the pads clamped on and transferring that heat to the other parts of the braking system.

That's how I would understand what Kieran is saying but then I'm only a learner driver

camerone

ChrisInBicester wrote:

camerone wrote:

hold on. how does having the brake on a stationary car cook the brakes? surely if the pad and the disc are static there is no heat? warp the discs? i have an automatic car, always have brake on when stationary and have not needed new discs in 60000 miles so far. are you driving a morris oxford?

Because the hot pads dissipate their residual heat into one area of the discs in a short space of time, which can cause it to warp. It's a very well known issue.

Ps - I'd hate to be the bloke behind you on a journey, having to sit behind a pair of brake lights at every set of lights. Try using the handbrake; have some awareness of what other motorists behind you are seeing when you sit with your foot on the brake at junctions & traffic lights.

hmm. how come all automatic drivers arent knackering their discs all the time? do they take it from drive into neutral or park whenever stationary?

Kieran_Burns

DevUK wrote:

camerone wrote:

hold on. how does having the brake on a stationary car cook the brakes? surely if the pad and the disc are static there is no heat? warp the discs? i have an automatic car, always have brake on when stationary and have not needed new discs in 60000 miles so far. are you driving a morris oxford?

Yes, but you'll have used them to stop though, so they'll already be hot. I can understand what Kieran is saying. When you've got heat into the discs you're then sitting with the pads clamped on and transferring that heat to the other parts of the braking system.

That's how I would understand what Kieran is saying but then I'm only a learner driver

Exactly that.

All the kinetic energy built up has to go somewhere, and that somewhere is the brake disc and pad. Holding the brakes on clamps the pad to the disc and can cause a hot spot - vented and groved discs minimise this but it can still be a problem. The heat transfer goes into the brake fluid as well and can cause it to boil (but only really under HEAVY braking)

Eau Rouge

I don't doubt that that could indeed happen in the right circumstances, but simply stopping a car to join a queue of traffic isn't going to generate enough heat to warp the discs. You'd have to be seriously working the brakes over a period of time to generate some real heat in the pads and the discs before this becomes something to worry about.
Holding the brakes on at the end of a track session would be a bad idea, doing it at the traffic lights isn't the same thing.

camerone

camerone wrote:

ChrisInBicester wrote:

camerone wrote:

hold on. how does having the brake on a stationary car cook the brakes? surely if the pad and the disc are static there is no heat? warp the discs? i have an automatic car, always have brake on when stationary and have not needed new discs in 60000 miles so far. are you driving a morris oxford?

Because the hot pads dissipate their residual heat into one area of the discs in a short space of time, which can cause it to warp. It's a very well known issue.

Ps - I'd hate to be the bloke behind you on a journey, having to sit behind a pair of brake lights at every set of lights. Try using the handbrake; have some awareness of what other motorists behind you are seeing when you sit with your foot on the brake at junctions & traffic lights.

hmm. how come all automatic drivers arent knackering their discs all the time? do they take it from drive into neutral or park whenever stationary?

PS i would hate to be behind you, fannying around with the handbreak whenever you are stationary. much rather be behind a non-ditherer who has their brake lights on.

camerone

Eau Rouge wrote:

I don't doubt that that could indeed happen in the right circumstances, but simply stopping a car to join a queue of traffic isn't going to generate enough heat to warp the discs. You'd have to be seriously working the brakes over a period of time to generate some real heat in the pads and the discs before this becomes something to worry about.
Holding the brakes on at the end of a track session would be a bad idea, doing it at the traffic lights isn't the same thing.

+1 perhaps after a 70mph-0 stop thjey need to cool, but ordinary circumstances - nah.

CiB

camerone wrote:

hmm. how come all automatic drivers arent knackering their discs all the time? do they take it from drive into neutral or park whenever stationary?

Because we're discussing two things at at once, as happens on internet forums. On the one hand, we have a position that says holding a car on the foot brake after some serious brake use which has generated a lot more heat than usual can cause discs to warp in some circumstances. In parallel, I'm supporting that theory and pointing out that it's also inconsiderate to other road users to sit in stationary traffic with the foot brake on as it has the effect of dazzling the driver behind, especially in the dark. These two factors both mean that using the foot brake is not a good default method of holding the car when stationary. Use the handbrake if the discs aren't already hot after a spirited bit of driving; use and or use the handbrake and P in your automatic at the lights etc.

Two different reasons, both arrive at the same conclusion. One benefits your vehicle, the other benefits other road users.

RedJohn

camerone wrote:

hmm. how come all automatic drivers arent knackering their discs all the time? do they take it from drive into neutral or park whenever stationary?

Well I do. Stops the car moving without using a brake at all, so the discs can cool down evenly. Takes about, oh, half a second to go from Drive to Park or vice versa.

Also, even automatics have handbrakes if that's what you really want to do, though I never use mine.

CiB

camerone wrote:

PS i would hate to be behind you, fannying around with the handbreak whenever you are stationary. much rather be behind a non-ditherer who has their brake lights on.

30 odd years of doing it means that the lights going amber, me slipping into first, handbrake smoothly off and away is no different to someone who sits with his foot on the brake. Sorry. You know what? I even push the button in when I pull the h/brake on. I'm that good.

It's to be expected that being made aware that your driving habits aren't as good as you thought would induce a snide response. Don't have a pop at me. I'm not the bloke who insists against all reason that the foot brake is the best method. Try Road Craft, The IAM, anyone who's bothered to look into it, rather than relying on your own relaxed method. Hey - you could even hop out at a junction where you know the lights will be red for 18 seconds and ask the guy behind if he prefers to have 2 red lights shine in his face for 18 seconds, or if he'd rather you pulled the h/brake on and took 0.4 seconds longer to start moving again.

rolf_f

Kieran_Burns wrote:

I had a 'difference of opinion' with this jobsworthtosspot who told people that when braking to join the rear of a standing line of traffic you should keep your foot on the brake pedal to ensure that the brake lights maximise your visibility to any other cars approaching from the rear.

I think what you are actually meant to do is keep an eye on what is going on behind and release the brakes once there is someone behind you.

As for non ditherers with their brake lights on - generally it is the non ditherers who are slowest off the line. They have to transfer their right foot from brake to throttle. The handbrake user already has their foot poised over the throttle and is therefore quicker. The only reason that the handbrake user should be slower is if they were trying to release the handbrake with their right foot

Mind you, it isn't as if the time difference would really bother anyone unless they were the sort to always have to overtake cyclists irrespective of whether or not doing so actually saves them any time!

Kieran_Burns

I wish I'd kept my fat mouth shut now

Oh, Rolf - this is actually what I said as well... seriously this guy had one idea stuck in his head and would simply not accept he could be wrong.

camerone

ChrisInBicester wrote:

camerone wrote:

PS i would hate to be behind you, fannying around with the handbreak whenever you are stationary. much rather be behind a non-ditherer who has their brake lights on.

30 odd years of doing it means that the lights going amber, me slipping into first, handbrake smoothly off and away is no different to someone who sits with his foot on the brake. Sorry. You know what? I even push the button in when I pull the h/brake on. I'm that good.

It's to be expected that being made aware that your driving habits aren't as good as you thought would induce a snide response. Don't have a pop at me. I'm not the bloke who insists against all reason that the foot brake is the best method. Try Road Craft, The IAM, anyone who's bothered to look into it, rather than relying on your own relaxed method. Hey - you could even hop out at a junction where you know the lights will be red for 18 seconds and ask the guy behind if he prefers to have 2 red lights shine in his face for 18 seconds, or if he'd rather you pulled the h/brake on and took 0.4 seconds longer to start moving again.

actually I know my driving habits are lazy., you havent pointed anything out I didnt already know. going back to original point i still maintain that in normal use there is no mechanical harm in doing it. my car operates the main braking circuit on the handbrake so no relief for the braking system, i might try it on the way home and see if its any more hassle to press the button on the dash than keep my foot on the brake pedal. i had no idea brake lights were so offensive.

cee

Rolf F wrote:

I think what you are actually meant to do is keep an eye on what is going on behind and release the brakes once there is someone behind you.

and then apply the handbrake anyway?? that doesn't make sense...the most efficient method would be to just apply the handbrake

i think that driving instructors and IAM's would say that if the car is stopped for longer than a brief moment, then you should apply the handbrake and change to neutral.....

The car is on a more controlled state that way, no matter how good a driver is...a mechanical lock is always more controlled than a perched foot.

I think however that i do a bit of both :oops:

unsure about the rudeness to other road users.......

Last comment...in normal driving conditions, holding your foot on the footbrake at the lights is not going to mechanically damage the brake system, warp the discs or anything bad...there is simply not enough heat and what is there is disspated quickly by design....unless you are really thrashing the car.....

Feltup

camerone wrote:

[
actually I know my driving habits are lazy., you havent pointed anything out I didnt already know. going back to original point i still maintain that in normal use there is no mechanical harm in doing it. my car operates the main braking circuit on the handbrake so no relief for the braking system, i might try it on the way home and see if its any more hassle to press the button on the dash than keep my foot on the brake pedal. i had no idea brake lights were so offensive.

They annoy the heck out of me.

CiB

camerone wrote:

...i still maintain that in normal use there is no mechanical harm in doing it. my car operates the main braking circuit on the handbrake so no relief for the braking system,

No-one disputes that; we were talking about spirited use and how brakes that are carrying a lot more heat than normal can warp the discs if the driver sits with his foot on the pedal. In normal use the h/brake is fine, the correct way.

camerone wrote:

i had no idea brake lights were so offensive.

Well you do now. They're not 'so offensive', just a bit annoying, one more thing that detracts from driving. Perhaps a handful more people will now be aware that dazzling the driver behind isn't best practice, and stop doing it. It can't do any harm can it if more drivers make an effort not to cause annoyance to other road users, to be helpful, to smile and wave them out at junctions, to switch fog lights off as soon as they become unnecessary, etc etc.

rolf_f

cee wrote:

Rolf F wrote:

I think what you are actually meant to do is keep an eye on what is going on behind and release the brakes once there is someone behind you.

and then apply the handbrake anyway?? that doesn't make sense...the most efficient method would be to just apply the handbrake

No, it does - honest! The point about the footbrake is that it is supposed to make you more visible to some numpty driving too quickly around the corner behind you whilst phoning and texting at the same time. Once there is a car behind you, you put the handbrake on (and obviously release the footbrake at the same time).

Stuey01

ChrisInBicester wrote:

Can I point out that the hydraulic disc brakes have caused the OP some angst. No? What the heck. Break = broken. Brake = stopping facility. I'll be off now.

I thought it was a rather good pun actually, as his brakes are broken.

Aidy

camerone wrote:

i had no idea brake lights were so offensive.

They don't really bother me.

cee

Rolf F wrote:

cee wrote:

Rolf F wrote:

I think what you are actually meant to do is keep an eye on what is going on behind and release the brakes once there is someone behind you.

and then apply the handbrake anyway?? that doesn't make sense...the most efficient method would be to just apply the handbrake

No, it does - honest! The point about the footbrake is that it is supposed to make you more visible to some numpty driving too quickly around the corner behind you whilst phoning and texting at the same time. Once there is a car behind you, you put the handbrake on (and obviously release the footbrake at the same time).

Just had a quick look on the IAM website and there is a tip about keeping your foot on the footbrake until the car drawing up behind you has stopped (although this tip is only in the Irish Advanced Motorists section....). But that is after making the car safe i.e. applying the handbrake and selecting neutral, not instead of or one or the other....

the visibility bit does make complete sense, as it did from the start of this topic. a red light is easier to see than ermmm no light!

nwallace

Stop, handbrake on, out of gear.
Check behind occasionally, put brake lights on if you see a need to indicate to an approaching vehicles that you are stopped, for example you have stopped short of a corner with a queue of traffic round it.

The clutch fluid pressure on My SAAB 99 starts to disappear after about 30 seconds, the brakes are much better, unlike british vehicles of similar age where after a few presses you start having to pump it.

rolf_f

nwallace wrote:

The clutch fluid pressure on My SAAB 99 starts to disappear after about 30 seconds, the brakes are much better, unlike british vehicles of similar age where after a few presses you start having to pump it.

Stop! You make me feel so ordinary in my Classic Saab 900