Brake pad slightly touching disc after new disc/pad installation is this normal?

[Chris_Music]

Hi guys,

I'm probably being paranoid here, but I just wanted to ask the question just in case.

So yesterday, I replaced the front and rear discs and pads on my Jazz for the first time (I've never done a disc pad change before). I'm pretty sure I got everything right. I watched 7 different youtube videos and wrote down all the steps and noted extra things people noted in the comments too and followed them to the letter.

The car drives fine, though I noticed the MPG has dropped a bit, so I jacked up each wheel to see if the pads were touching the discs, which could cause the MPG to drop if there was that resistance, and all 4 wheels the pads were touching the discs slightly. Spinning it round sounded like the TARDIS sound effect (google it if you aren't familiar), but not quite as dramatic as that.

Is this normal? I've driven about 35miles in the car so far, and have been breaking very lightly. So I wasn't sure if it's just a case of bedding in the new brakes and it will be fine after a couple of hundred miles.
Also 35 miles probably isn't enough to know if it is really affecting the MPG, but normally after a milage reset on the tip meter, the MPG would be higher. Currently sitting at 42mpg.

But anyway, hopefully someone can reassure my anxiety!

Thanks in advance!

[Lord Voltermore]

The gap between pad and disc is normally quite small anyway and may need to bed in a bit. (in other words wear down a bit)    If when you changed the pad and disc the calipers were clean and their sliding pins were clean and free of corrosion   they will probably settle down.

You probably needed to push the brake piston/s  back into  their bores  when fitting new pads  which can  raise the level of fluid in the brake  reservoir,   but done correctly there should be no need for bleeding the brakes.
Another possible pitfall when changing discs is    not  checking that the mating surface between the disc and where its bolted to the hub  is clean and free of loose rust etc. Trapped crud may mean the disc does not run true. 

I'm not sure 'braking lightly' is the best approach  after fitting new pads etc.   The brakes will bed in quicker if you brake harder than normal for a while. ( allowing a bit more margin to allow for  any temporary loss of efficiency)   I wouldnt 'pussy foot'  with them.. Give em some welly .    Poorly bedded  brakes may be sufficient for light braking but may  not yet deliver 100% efficiency, should you need it in a hurry. 
 
I'd give it a while to see if things bed down and improve.  If there is a doubt the callipers etc are 100% clean try using some brake cleaner spray.      If things  get worse, or you still have doubts  , get them checked by a professional.    (but dont expect them to do so as part of a 'free brake check' deal    )

[Neil Ives]

There is no mechanism to retract the brake pads;  slight runout of the disk pushes the pads away from the surface but only the thickness of paper. At the moment your new pads will have a rough/hairy surface that is slightly rubbing the disk. When the brakes have been used for a while the surface of the pads will be much smoother and will not, (should not) rub.

[guest334]

Maybe give it another 200 miles, but avoid heavy breaking.

[Westy36]

So yesterday, I replaced the front and rear discs and pads on my Jazz for the first time (I've never done a disc pad change before). I'm pretty sure I got everything right. I watched 7 different youtube videos and wrote down all the steps and noted extra things people noted in the comments too and followed them to the letter.

Good work. That's exactly how I go about repairs. Having watched it done on YTube a few times and read forum posts etc gives me the confidence to have a bash. Think of all the money you've saved, Honda currently quote the repair at £700 !! https://www.honda.co.uk/cars/owners/repairs.html

I agree with others, they'll bed in over time. 35 miles is not far. Gradualy increase breaking pressure over time, get them bedded in nicely.

[Lord Voltermore]

Maybe give it another 200 miles, but avoid heavy breaking.

On reflection  I was a bit over enthusiastic in saying 'give em some welly'.   But being overly gentle just prolongs the time it takes for them to bed in nicely. 

       But that said where drivers  are habitually gentle on brakes  ,or the car doesnt get a lot of use, brake parts can  rust or clog . They will benefit from a few harder than normal  presses on the brakes every now and again  to help get things moving and to clear away any surface rust forming on the discs. 

[Neil Ives]

No matter that I intend to drive minimising use of the brakes some twit BMW driver will pull across my path without signalling meaning I need to put the anchors on hard. 

[Chris_Music]

Thank you for all the replies

The gap between pad and disc is normally quite small anyway and may need to bed in a bit. (in other words wear down a bit)    If when you changed the pad and disc the calipers were clean and their sliding pins were clean and free of corrosion   they will probably settle down.

I cleaned the caliper, first with a wire brush, then with brake cleaner. I cleaned and re-greased the sliding pins with silicone grease.

You probably needed to push the brake piston/s  back into  their bores  when fitting new pads  which can  raise the level of fluid in the brake  reservoir,   but done correctly there should be no need for bleeding the brakes.
Another possible pitfall when changing discs is    not  checking that the mating surface between the disc and where its bolted to the hub  is clean and free of loose rust etc. Trapped crud may mean the disc does not run true.

I removed the brake reservoir cap and pushed the brake pistons back into the calliper. I also pumped the brakes afterwards. The fluid level did rise higher than it was when I started. I assumed this would go back down after using the brakes for a bit.

The hub was pretty clean to be fair, basically no rust. I did clean it with brake cleaner and then put some copper grease on the hub just to make the disc removal easier after the next 50k miles.

I'm not sure 'braking lightly' is the best approach  after fitting new pads etc.   The brakes will bed in quicker if you brake harder than normal for a while. ( allowing a bit more margin to allow for  any temporary loss of efficiency)   I wouldnt 'pussy foot'  with them.. Give em some welly .    Poorly bedded  brakes may be sufficient for light braking but may  not yet deliver 100% efficiency, should you need it in a hurry. 

When I've had disc and pad changes before, the mechanic has always said take it easy on the brakes for a bit, so that's what I've been doing. But today I was a bit harder with them. Don't want to do an emergency stop just yet, but I'm sure some idiot will pull in front of me on my way to work tomorrow because I just jinxed it now.

No matter that I intend to drive minimising use of the brakes some twit BMW driver will pull across my path without signalling meaning I need to put the anchors on hard. 

Literally happened to me a few years back. Brand new brake pads/discs, and a new rear calliper on my old GD, and literally the roundabout after leaving the mechanics, someone braked hard in front of me all of a sudden, and I had to slam on the brakes. I watched the Dashcam footage back because you could hear me screaming "FOR GODS SAKE, THE BRAKES!!", haha.

Good work. That's exactly how I go about repairs. Having watched it done on YTube a few times and read forum posts etc gives me the confidence to have a bash. Think of all the money you've saved, Honda currently quote the repair at £700 !! https://www.honda.co.uk/cars/owners/repairs.html

Thanks, it took me about 6.5 hours to do, and I'm glad it's something I will only have to do every 50k miles, as it was a pain to do, but I was being overly careful, and cleaning everything and making sure I was doing everything right, so it was probably worth it just for that. Probably a more thorough job than I would get from taking it to a garage.

There is no mechanism to retract the brake pads;  slight runout of the disk pushes the pads away from the surface but only the thickness of paper. At the moment your new pads will have a rough/hairy surface that is slightly rubbing the disk. When the brakes have been used for a while the surface of the pads will be much smoother and will not, (should not) rub.

Thank you, yes this makes a lot of sense. I'm just being paranoid because it's the first time I've done this myself, and it's something really important like the brakes!!

The brakes did feel a bit better today actually.

Fuel economy still poor, but I will keep an eye on that.

[Neil Ives]

Well done. You saved a lot of money doing it yourself.

[Lord Voltermore]

No matter that I intend to drive minimising use of the brakes some twit BMW driver will pull across my path without signalling meaning I need to put the anchors on hard. 

More the driver than their choice of car I think.   Those that pull out in front of me in a dangerous way   more often than not continue to prove their total driving incompetence  by  not accelerating up to speed at a normal rate, and driving  abnormally slowly and badly. 

I believe  some police forces run schemes where you can submit dashcam evidence of bad driving, but it rarely results in a prosecution due to the difficulties of proving evidence in court,dashcammers being called as witnesses etc. .   I 'd like to see a scheme where if a particular registration number  accumulates say 3 videos of concern  the driver is required to take a 'lesson' with an approved driving instuctor to prove they are still competent to drive. Fail that and they must take a full  driving test.    No need to involve the courts, or witnesses,who are thus more likely to submit videos. (assuming their camera is clear enough to read registration numbers ) The proof of the pudding is the driver can either prove their competence or they cant.       It wont work so well for younger drivers driving like idiots . They can behave themselves long enough to pass a test, but if they accumulate enough concerns then action through the courts might be appropriate.   

Lets be honest here. There are some  drivers,and not just older ones, who may be deluding themselves about their current driving competence.    And although its true that experience can make up for inexperienced and impetuous youth, some drivers were never particularly competent even when younger and have gone downhill ever since.     I would like to think that when the time comes for me to stop driving, I will know and do so voluntarily. I'd hate to rely on "being ok on roads I know". (You're not, the situation is never the same twice. )   But if it takes a kick in the bum  from an independent assessor, so be it. 

[Neil Ives]

No matter that I intend to drive minimising use of the brakes some twit BMW driver will pull across my path without signalling meaning I need to put the anchors on hard. 

More the driver than their choice of car I think.   

The BMW has an image that suits their ego.

Those that pull out in front of me in a dangerous way   more often than not continue to prove their total driving incompetence  by  not accelerating up to speed at a normal rate, and driving  abnormally slowly and badly. 

I believe  some police forces run schemes where you can submit dashcam evidence of bad driving, but it rarely results in a prosecution due to the difficulties of proving evidence in court,dashcammers being called as witnesses etc. .   I 'd like to see a scheme where if a particular registration number  accumulates say 3 videos of concern  the driver is required to take a 'lesson' with an approved driving instuctor to prove they are still competent to drive. Fail that and they must take a full  driving test.    No need to involve the courts, or witnesses,who are thus more likely to submit videos. (assuming their camera is clear enough to read registration numbers ) The proof of the pudding is the driver can either prove their competence or they cant.       It wont work so well for younger drivers driving like idiots . They can behave themselves long enough to pass a test, but if they accumulate enough concerns then action through the courts might be appropriate.   

Lets be honest here. There are some  drivers,and not just older ones, who may be deluding themselves about their current driving competence.    And although its true that experience can make up for inexperienced and impetuous youth, some drivers were never particularly competent even when younger and have gone downhill ever since.     I would like to think that when the time comes for me to stop driving, I will know and do so voluntarily. I'd hate to rely on "being ok on roads I know". (You're not, the situation is never the same twice. )   But if it takes a kick in the bum  from an independent assessor, so be it.

How about making the driving test harder; it needs to be able to test cognative ability; also dealing with ice and snow.

[Jocko]

also dealing with ice and snow.

How do you do that? Last winter we had about five hours of lying snow and no ice. Would drivers have to do part of their test in Scandinavia?

[Neil Ives]

also dealing with ice and snow.

How do you do that? Last winter we had about five hours of lying snow and no ice. Would drivers have to do part of their test in Scandinavia?

Well that's the problem;  when it happens most drivers have never learnt how to respond when their car looses traction. I guess some time on a skid pan is the answer.

[Lord Voltermore]

I managed to get a couple of sessions on a skid pan when I was younger and learned a lot  .But cars were mostly rear wheel drive at the time,which respond differently.      Even now if I see an empty car park covered in snow or ice  I will have a 'play' to keep in practice. 
    Only about a month ago  my car skidded badly on a roundabout, due to spilled oil.  I thought it was diesel and not much of a problem as the weather was dry,.  But it must have been engine oil. and the car slid on only a slight bend.  .  My bad     
   I managed to regain control,  but how much was due to my reactions, and how much was due to the cars traction control ' bag of tricks' I'm not entirely sure.

My wife can only recall ever skidding  once "years ago"  on  ice.   Its probably not something to be proud of but I can recall many occasions when I have skidded on snow ,ice, loose gravel, etc . To be fair  I often had to drive in snow for my job, she could avoid it.   Maybe skid pan experience made me over confident, and I pushed the limits on the road. But I have always been able to regain control without crashing, and  have maybe included some minor 'twitches'  that  more cautious and inexperienced driver might not even register as a momentary loss of control (until its bad enough  to 'bite them on the bum').   So its swings and roundabouts really  (excuse pun) . Skid pan training and maybe become over confident, or cautious and hope for the best.     

[Neil Ives]

The thing about loosing grip is that panic can make the driver put on the anchors and that is probably the worst thing to do. In my experience, loosening grip on the steering wheel allows the car to get itself straight and in the days before ABS dabbing the brake pedal.

I had a long wheelbase MK2 Land Rover for many years. One time, soon after I got the car, snow had been falling all day. I was driving home from work. I was loving the fact that I could put the Landy in four-wheel drive and the snow would be nothing to worry about. I had to make a right turn. As I made the turn the vehicle spun right round so it was facing the way I'd come from! My analysis of what happened was: I took my foot of the gas to make the turn. The front wheels, carrying the weight of the engine, gripped the road, the back wheels lost grip. The car pivoted around the front wheels. After that whenever there was snow I carried some bags of gravel in the back to give it some ballast.