Thanks everyone for your speedy replies... I'll be looking into the suggestions. : )
Brake caliper screws & wheel bearings
- Thread starter pretzelz
- Start date
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If the brake pads slip back over the disc, then the piston is in far enough. Look at the gold coloured sleeves surrounded by rubber circular concertina things; they move.. They have to to let the caliper float (by design)
Youre struggling to get the caliper back in place because the gold coloured sleeve is contacting the mounting plate. Push it out of the way (i.e. push it away from the and refit the caliper)
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Last point of note when replacing brake pads, i normally undo the bleed nipple on the caliper before I push the piston back in. Not only does it help remove what could be years-old dodgy brake fluid, but it does make it considerably easier to push the piston in. Tighten the nipple again as soon as youre done pushing in the piston
No because youre inside the car and the caliper is outside the car
though if you had an assistant push the pedal you would see the piston move slightly, and retract slightly when the pedal was released. It doesnt fly out, and it doesnt move by much, because if it did you wouldnt be able to get much force when braking (you may remember force/distance multipliers from physics)It might not be supposed to tighten all the way into what you think is "in" depending on the bearing design. Further, given that most brake discs are held in place by the wheel nuts, they do not make a good place to grasp ahold of when doing wiggle tests. If your wheel bearing is worn to the point that you could discern an obvious amount of movement by wiggling the wheel (note I said wheel to imply you should bolt the wheel back on, not wigggle the brake disc), you'd most certainly hear a horrendously loud, constant grumbling noise while driving, worsening round corners that load the wheel up, and lessening round corners that remove load from the wheel (worn driver side bearning, louder grumbles round left hand bends, quieter round right handers)
It depends on the design of the bearing and the construction of the wheel hub. If you can post a video of you wiggling what you think is a problem, it would be more helpful. Do not attempt to tighten or slacken this nut if you have not done so already. The manufacturer's torque it is to be set to should be followed precisely to avoid premature bearing wear
It normally looks like a flower or might be called macro, the zoom should be a Wide as possible (zoom out) and you should not go any closer than the focal distance the camera manufacturer specified. Further you should ensure youre using the 2 stage push of the shutter button correctly and that youre holding the camera still if flash is not in use. If the camera provides an indication that it has acquired a good focus lock, then ensure it has. On my camera, the crosshairs are green if it focused and red if it didnt. If you are in a low light situation, the muscular effort required to press the shutter button can shake the camera. In this case it is best to set the camera to its lowest self timer mode (mine has a 2 second timer), press the button to focus, take the shot and then while the camera is counting down to take the photo, keep still and breathe out slowly (holding your breath or breathing in inhibits your ability to keep steady - learned this in rifle shooting class)
wow cjard, thank you for the insightful post, very much appreciated for your time in writing that! And the diagram.
Friday afternoon, as long as it isn't raining I shall be outside trying the suggested remedies. ...and yes, when the wheel is mounted, it still rocks the few mm back and forth.
I guess I'll be able to give some report on the noise the wheel makes (regarding bearing) once I can test it with the new brake pads and disc. Because my car was making such a terrible noise previously, people on the pavement would turn their heads when I drove past. I could easily have recorded the noise from inside the car, it was horrendous and cringingly loud. So now all of this.
View media item 7638
Initially when noises started, (if anyone's interested) there was a loose knocking sound coming from my wheel. Sounded possibly like the brake pads were loose - the old ones were indeed pretty loose in the caliper once i took it off the wheel. Or rather, the one pad was loose that fits into the piston hole. But did sound very much like a pendulum was hanging near the wheel and sometimes swinging and hitting the chasis.
Then gradually after the knocking noise started, a new metalic scraping sound would occur near to stopping, and the worse it got, the more prevelant it because up to about 35 mph. It was gone at fast speeds. When slowing down at traffic lights at a few miles per hour, you could hear it was in sync with the complete rotation of a wheel. So that could possibly have been the grazing rust spot on my old disc brake. Also I'm pretty sure it was to do with applying brake pressure when my foot was slightly down on the brake. But sometimes when my foot wasn't on the brake, so the rust of the disc might still have been rubbing with the pads. And on top of that, the pad in the caliper was very thin, about 1 or 2mm. The other pad was much thicker. I thought they'd wear at about the same rate.
I did look online for some short car courses in Southampton and couldn't find any really that looked suitable. Some down to the point classes on fiddling about with the wheel, exhaust, engine and bleeding would have been useful. So if you're good on DIY auto and in Southampton then I may at somepoint call on your to teach me a few essential ropes for money. Alternatively you could start up your own class and get in some pupils. Maybe even just a single spare weekend, I think there would be some takers. But that's another topic.
Friday afternoon, as long as it isn't raining
I shall be outside trying the suggested remedies. ...and yes, when the wheel is mounted, it still rocks the few mm back and forth.I guess I'll be able to give some report on the noise the wheel makes (regarding bearing) once I can test it with the new brake pads and disc. Because my car was making such a terrible noise previously, people on the pavement would turn their heads
when I drove past. I could easily have recorded the noise from inside the car, it was horrendous and cringingly loud. So now all of this.View media item 7638
Initially when noises started, (if anyone's interested) there was a loose knocking sound coming from my wheel. Sounded possibly like the brake pads were loose - the old ones were indeed pretty loose in the caliper once i took it off the wheel. Or rather, the one pad was loose that fits into the piston hole. But did sound very much like a pendulum was hanging near the wheel and sometimes swinging and hitting the chasis.
Then gradually after the knocking noise started, a new metalic scraping sound would occur near to stopping, and the worse it got, the more prevelant it because up to about 35 mph. It was gone at fast speeds. When slowing down at traffic lights at a few miles per hour, you could hear it was in sync with the complete rotation of a wheel. So that could possibly have been the grazing rust spot on my old disc brake. Also I'm pretty sure it was to do with applying brake pressure when my foot was slightly down on the brake. But sometimes when my foot wasn't on the brake, so the rust of the disc might still have been rubbing with the pads. And on top of that, the pad in the caliper was very thin, about 1 or 2mm. The other pad was much thicker.
I thought they'd wear at about the same rate. I did look online for some short car courses in Southampton and couldn't find any really that looked suitable. Some down to the point classes on fiddling about with the wheel, exhaust, engine and bleeding would have been useful. So if you're good on DIY auto and in Southampton then I may at somepoint call on your to teach me a few essential ropes for money. Alternatively you could start up your own class and get in some pupils. Maybe even just a single spare weekend, I think there would be some takers. But that's another topic.
The noise you describe sounds like a fairly standard brake scraping noise that becomes evident when pads get really low. My volvo currently has 4mm of material on all pads and the main dealers are saying they need replacing
Some pads are fitted with metal fingers or other design features that make a scraping noise when the pad is worn (but still useable) to encourange the owner to change the pad. I can only commend such an action as I've seen brake assemblies where not only the pad, but the metal pad backing and half of the piston has worn away because the rider failed to change the pads - in the end, the piston popped out, leaked brake fluid everywhere and he lost brakes. It's comforting to know that nuggets like this will be fathering future generations.
if your wheel bearings are the press-in type (typically shaped like a bog roll rather than a cone) you might find it easier to just go along to a scrap yard and buy another knuckle/hub/bearing assembly (in your pics, its the thing you bolted the brake caliper to) because it should be a low number of bolts to remove (one on the suspension, one on the wishbone and one on the track rod) and it sure beats messing around finding a workshop with a press to put a bearing in. Additionally, if a bearing isn't pressed in correctly and evenly it'll wear out in 10 or 20K. This is most definitely not something you can do at home with a hammer and after going through all the hassle on my mondeo, i genuinely wish I'd just gone and got another off a fairly low miles one from a scrappie
I dont have any experience with conical bearings but I don't think they'll need pressing. With conical bearings it's very important that the retaining nut is torqued up correctly.
In both cases, for some cars, the nut that retains the bearing/driveshaft (in the centre of the wheel) the nut is of a special type and should not be refitted after removal. Replace it with a new one.
If your pads arent wearing at the same rate, it could be because they are different materials (unlikely but possible if someone has mixed and matched) or because your caliper is not floating correctly. The gold coloured spacers I referred you to should float easily back and forth. Calipers of this type have a piston on one side only, so they are designed tha tthe piston's pushing out can cause the entire caliper assembly to move so as to make the outer pad rub the outer face of the disc. If the sliders stick, the braking effort comes from pressure exerted by the piston on one face only. The effort required to stop the car will be considerably greater.
Car courses probably wouldnt teach you how to do a wheel bearing (i expect they would cover service items like oil and filters changing, alternator belts etc), but they might get you into basic toolmanship.. It sounds funny, but there is a correct (and many incorrect) ways to use every tool. Even something as simple as a hammer, has a correct way to swing it in every situation and it's something that is very hard to teach. I was amazed and somewhat saddened to see my brother's friends (all in the building trade) fail at a fairground game where they had to drive a nail into a wooden beam using 3 strikes. The way they swung the hammers, it's no wonder that nails were flying all over the place or only went in a few centimetres..
Some pads are fitted with metal fingers or other design features that make a scraping noise when the pad is worn (but still useable) to encourange the owner to change the pad. I can only commend such an action as I've seen brake assemblies where not only the pad, but the metal pad backing and half of the piston has worn away because the rider failed to change the pads - in the end, the piston popped out, leaked brake fluid everywhere and he lost brakes. It's comforting to know that nuggets like this will be fathering future generations.
if your wheel bearings are the press-in type (typically shaped like a bog roll rather than a cone) you might find it easier to just go along to a scrap yard and buy another knuckle/hub/bearing assembly (in your pics, its the thing you bolted the brake caliper to) because it should be a low number of bolts to remove (one on the suspension, one on the wishbone and one on the track rod) and it sure beats messing around finding a workshop with a press to put a bearing in. Additionally, if a bearing isn't pressed in correctly and evenly it'll wear out in 10 or 20K. This is most definitely not something you can do at home with a hammer and after going through all the hassle on my mondeo, i genuinely wish I'd just gone and got another off a fairly low miles one from a scrappie
I dont have any experience with conical bearings but I don't think they'll need pressing. With conical bearings it's very important that the retaining nut is torqued up correctly.
In both cases, for some cars, the nut that retains the bearing/driveshaft (in the centre of the wheel) the nut is of a special type and should not be refitted after removal. Replace it with a new one.
If your pads arent wearing at the same rate, it could be because they are different materials (unlikely but possible if someone has mixed and matched) or because your caliper is not floating correctly. The gold coloured spacers I referred you to should float easily back and forth. Calipers of this type have a piston on one side only, so they are designed tha tthe piston's pushing out can cause the entire caliper assembly to move so as to make the outer pad rub the outer face of the disc. If the sliders stick, the braking effort comes from pressure exerted by the piston on one face only. The effort required to stop the car will be considerably greater.
Car courses probably wouldnt teach you how to do a wheel bearing (i expect they would cover service items like oil and filters changing, alternator belts etc), but they might get you into basic toolmanship.. It sounds funny, but there is a correct (and many incorrect) ways to use every tool. Even something as simple as a hammer, has a correct way to swing it in every situation and it's something that is very hard to teach. I was amazed and somewhat saddened to see my brother's friends (all in the building trade) fail at a fairground game where they had to drive a nail into a wooden beam using 3 strikes. The way they swung the hammers, it's no wonder that nails were flying all over the place or only went in a few centimetres..
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Today I worked on the car again. I tried to push the brass bit back, but it was completely unflexible. Just would not budge.
So while I was out there, another comment from this board came to mind. Filing one of the new brake pads down.
But, I thought, do I really want to loose some of a new brake pad I've just paid for? ...noticing that one of my old brake pads still hadn't worn to a minimum, there was about 3 or 4 mm left on it, I decided, how about compliment this old brake pad with a new pad in the piston.
Result! I had no problem fitting the caliper back on the wheel. I lowered the car and pumped the pedal a few times... it felt very spongey like air was trapped in it. I decided to start the car and go back and forth in the driveway a few times and see how the new brake pad reacted. After a few pumps back and forth, the pedal felt back to normal. It felt responsive.
I decided to take the car slowly out round the local quiet suburb. For the first time in a long while, I was amazed that the car was quiet, no scraping sound from the wheel, and no periodic (each rotation) grazing rub sound (from I presume the rusty spot on the old disc).
I took the car up to about 20mph and applied the brake as normal, and did a fair amount of cornering. No noise from the wheel at all.
In the evening I took the car for a 10min drive on main roads to get petrol and see a friend. When I got back home, all was still fine.
Now though, for my questions.
1. I'm using an old brake pad with the new one. I thought I could perhaps wait for the new pad to naturally wear down a few mm so I could then have both new pads in the caliper to fit the wheel. However, I'm not sure as to the condition of the old pad, as it had been previously rubbing over the old rusty disc. Is it wise to have this against a nice new shiney brake disc? Or will it corrode the new disc in some way.
2. With regards to my shakey 12 and 6 o'clock wheel, when the car was raised and the wheel went back on, the wheel really could be juddered about 5mm forward or back. And i could see the whole assembly move with it behind the wheel. It's probably not good to be driving like that. And if it is a case of that central nut not going on tight enough, where can I find another nut that fits? It's bigger than any of my socket sizes too, so I wasn't able to see if a wrench could have tightened it better.
3. So does my wheel now show NO signs of it being the wheel bearing at fault? There is no noise when going round corners, or travelling at all. And in which case, I spent £26+ vat on a wheel bearing which isn't being used. Should I hang onto it or try and sell it? I doubt anyone with my car will be looking for one who aims to DIY their vehicle.
Today -- perhaps I'll assess the state of the other front wheel, and look in particular at the central nut, since that wheel doesn't wobble. If I can remove the nut, and try it on the wobbly wheel, and it fixes the problem, then I can just get a new nut I presume. (but what is the nut?)
Thanks for all your insight.
Today I worked on the car again. I tried to push the brass bit back, but it was completely unflexible. Just would not budge.
So while I was out there, another comment from this board came to mind. Filing one of the new brake pads down.
But, I thought, do I really want to loose some of a new brake pad I've just paid for? ...noticing that one of my old brake pads still hadn't worn to a minimum, there was about 3 or 4 mm left on it, I decided, how about compliment this old brake pad with a new pad in the piston.
Result! I had no problem fitting the caliper back on the wheel. I lowered the car and pumped the pedal a few times... it felt very spongey like air was trapped in it. I decided to start the car and go back and forth in the driveway a few times and see how the new brake pad reacted. After a few pumps back and forth, the pedal felt back to normal. It felt responsive.
I decided to take the car slowly out round the local quiet suburb. For the first time in a long while, I was amazed that the car was quiet, no scraping sound from the wheel, and no periodic (each rotation) grazing rub sound (from I presume the rusty spot on the old disc).
I took the car up to about 20mph and applied the brake as normal, and did a fair amount of cornering. No noise from the wheel at all.
In the evening I took the car for a 10min drive on main roads to get petrol and see a friend. When I got back home, all was still fine.
Now though, for my questions.
1. I'm using an old brake pad with the new one. I thought I could perhaps wait for the new pad to naturally wear down a few mm so I could then have both new pads in the caliper to fit the wheel. However, I'm not sure as to the condition of the old pad, as it had been previously rubbing over the old rusty disc. Is it wise to have this against a nice new shiney brake disc? Or will it corrode the new disc in some way.
2. With regards to my shakey 12 and 6 o'clock wheel, when the car was raised and the wheel went back on, the wheel really could be juddered about 5mm forward or back. And i could see the whole assembly move with it behind the wheel. It's probably not good to be driving like that. And if it is a case of that central nut not going on tight enough, where can I find another nut that fits? It's bigger than any of my socket sizes too, so I wasn't able to see if a wrench could have tightened it better.
3. So does my wheel now show NO signs of it being the wheel bearing at fault? There is no noise when going round corners, or travelling at all. And in which case, I spent £26+ vat on a wheel bearing which isn't being used. Should I hang onto it or try and sell it? I doubt anyone with my car will be looking for one who aims to DIY their vehicle.
Today -- perhaps I'll assess the state of the other front wheel, and look in particular at the central nut, since that wheel doesn't wobble. If I can remove the nut, and try it on the wobbly wheel, and it fixes the problem, then I can just get a new nut I presume. (but what is the nut?)
Thanks for all your insight.
You should take the old pad out and fit the new one, you mustn't have the piston all the way in or one of the slides is seized. Have a wee look at the link, it might be helpful.
http://www.youtube.com/results?search_query=How+to+Assemble+a+Brake+Caliper&search_type=&aq=f
Re your hub nut, you'll get a new one at your dealer or get yourself a socket that fits.
http://www.youtube.com/results?search_query=How+to+Assemble+a+Brake+Caliper&search_type=&aq=f
Re your hub nut, you'll get a new one at your dealer or get yourself a socket that fits.
ok... you'll all cringe, but i'll report this to you anyway.
I drove to my friends house this evening. When I got there and looked at the wheel, i noticed the centre cap was missing...
I got a torch, looked through the hole, and saw... just a WASHER! No Nut!
So now my car is parked outside his house, and I got a lift home.
Tomorrow I'm going to go to a nearby hardware store and ask if they have any hub nuts, but I don't know which size I need. I guess 30mm.
By the way, I didn't see any cotter pins in the old nut when I disassembled the wheel. But on the box that came with my new brake disc, the back diagram showed a cotter pin fitting into the nut, or near it.
How could that nut have come off so easily? And if I get a 30mm socket hopefully that will get it on tighter than I did the first time around!
I drove to my friends house this evening. When I got there and looked at the wheel, i noticed the centre cap was missing...
I got a torch, looked through the hole, and saw... just a WASHER! No Nut!
So now my car is parked outside his house, and I got a lift home.
Tomorrow I'm going to go to a nearby hardware store and ask if they have any hub nuts, but I don't know which size I need. I guess 30mm.
By the way, I didn't see any cotter pins in the old nut when I disassembled the wheel. But on the box that came with my new brake disc, the back diagram showed a cotter pin fitting into the nut, or near it.
How could that nut have come off so easily? And if I get a 30mm socket hopefully that will get it on tighter than I did the first time around!
If you get one of those nuts at a hardware store I'll chew my nuts off. Go to your Daihatsu dealer and get the right one for it. There is no split pin, once you get the nut to the correct torque you tap the end of the nut into a groove to stop it loosening.
I take it your nuts look like the ones in the link.
http://www.eliseparts.com/shop/index.php?main_page=product_info&products_id=623
Try that.
I take it your nuts look like the ones in the link.
http://www.eliseparts.com/shop/index.php?main_page=product_info&products_id=623
Try that.
Yep, although the links aren't working for me anymore? At least the ones on the previous page.
Yes I was planning to go to a hardware store, but now you've pointed out i need to visit an official dealer, i looked them up but they are all a long way out from southampton. And kinda hard to get to them on a moped. Maybe I could phone the place that sold me the bearing, disc and pads for my car, southern exhausts or something.
See, I didn't realise the nut had to be tapped into a groove to stop it coming out. I wonder how long i was driving around with only the brake pads holding the wheel on in the caliper. Scary. (yet smoothest ride the car has been for a long while)
Yes I was planning to go to a hardware store, but now you've pointed out i need to visit an official dealer, i looked them up but they are all a long way out from southampton.
And kinda hard to get to them on a moped. Maybe I could phone the place that sold me the bearing, disc and pads for my car, southern exhausts or something. See, I didn't realise the nut had to be tapped into a groove to stop it coming out. I wonder how long i was driving around with only the brake pads holding the wheel on in the caliper. Scary. (yet smoothest ride the car has been for a long while)
Try a scrappy then. As long as the new (2nd hand) nut stops in a place where you still have something to knock in you'll be ok. If you can get one from a scrappy it'll buy you time so that you can get a new one.
That is the cause of the uneven pad wear. I guarantee those brass things are supposed to float; that's why they have flexible rubber concertinas around them to keep out dirt. If they were supposed to just be a solid block then the manufacturer would NOT go to all the effort of installing a fixed brass spacer and rubber concertinas; it would just be a cast extension of the caliper itself!
NO NO NO. There's a golden rule in mechanics (actually in anything, apart from That One Thing):
If it's hard, youre doing it wrong
If you'd care to point out the person who advised you to file down the correct-and-designed-for-your-car pads I'll gladly flog them too; pads fit. If they don't, something is wrong. You should not risk a variety of colourful and unpleasant lung diseases, breathing in the dust that filing brake pads would generate.
NO NO NO. Pads are supposed to work in pairs and be of the same material. You cannot guarantee that your old and new pads are matched Further, your pad is now installed in the opposite rotational direction to that which it has spent its entire life in. This can only cause problems, not be a solution.
No, it's not. If your caliper is not floating then it is not working properly or as designed. If youre not prepared to listen to any other advice I give you then please at least listen to this:
Take your car to Kwik Fit, ATS, local garage, whoever and get them to do your brakes for you. Using a car with defective brakes is a criminal offence and carries a heavy fine and penalty points in the magistrates court. Further you are risking the lives of everyone who travels in that car. In an emergency situation, if you slam the brakes hard, that brass ferrule may suddenly come unstuck and the massive amount of play that the caliper float creates will mean that you lose all braking. Even if you are quickwitted enough to pump the pedal sufficiently to re-settle the pads on the disc, you risk depleting the vacuum assistance reservoir which means that you won't be able to exert enough force on the pedal to stop the car safely.
You have created an accident waiting to happen that could injure you and those around you. You must take responsible steps to rectify this immediately
Please, take your car to a professional mechanic
Please, take your car to a professional mechanic
Please, take your car to a professional mechanic
Please, take your car to a professional mechanic
Remember; driving or selling a vehicle with defective brakes is a criminal offence. Defective brakes is 3 points and a £60 fine per wheel if dealt with by FPN, and 3 points and a fine between 75% and 125% of your weekly income before tax. If you do not provide income details, £350 is assumed. The maximum fine is £2500.
The advice is much appreciated, but how can I learn to do my own brakes if I just take it to a mechanic?
You can watch. You can get a part time job in a garage if you really care.
If youre going to do the job you've done and be satisfied that it's acceptable then you, anyone who travels with you and anyone who shares a road with you would be safer if you would not learn at all.
Perhaps you should learn basic mechanic skills on a less life-threatening system, that way by the time you come to work on a crucial system such as brakes you will be able to assess the state of that system before, during and after repair and you will instinctively know when something is right and when something is wrong.
Looking at those brass slides and presuming they are supposed to be seized solid just because you cannot move them witha finger, or regarding putting an old brake pad in as an acceptable solution ought to be massive indicators that youre not competent enough right now to be doing this kind of work. Start with something that is less likely to kill someone, like changing an alternator belt or an oil filter.
Don't make changing brakes the first thing you do as a complete mechanical noob if youre not going to listen to advice that could mean the difference between life and death, not necessarily yours.
If youre going to do the job you've done and be satisfied that it's acceptable then you, anyone who travels with you and anyone who shares a road with you would be safer if you would not learn at all.
Perhaps you should learn basic mechanic skills on a less life-threatening system, that way by the time you come to work on a crucial system such as brakes you will be able to assess the state of that system before, during and after repair and you will instinctively know when something is right and when something is wrong.
Looking at those brass slides and presuming they are supposed to be seized solid just because you cannot move them witha finger, or regarding putting an old brake pad in as an acceptable solution ought to be massive indicators that youre not competent enough right now to be doing this kind of work. Start with something that is less likely to kill someone, like changing an alternator belt or an oil filter.
Don't make changing brakes the first thing you do as a complete mechanical noob if youre not going to listen to advice that could mean the difference between life and death, not necessarily yours.
I'm glad you and your neighbours are still alive. Do follow cjard's advice and get someone to fix it for you properly.
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