Discussion
Hi
Is there any way of determining whether brake discs are warped via a visual inspection?
I'm getting a lot of pedal judder and as the rear discs were replaced 2K ago I assume its the front set ?
Also, replacing discs and pads seems to be fairly straight forward and as I have a decent sized garage I thought I'd tackle it myself - any pitfalls to watch out for ?
All advice gratefully received !
Is there any way of determining whether brake discs are warped via a visual inspection?
I'm getting a lot of pedal judder and as the rear discs were replaced 2K ago I assume its the front set ?
Also, replacing discs and pads seems to be fairly straight forward and as I have a decent sized garage I thought I'd tackle it myself - any pitfalls to watch out for ?
All advice gratefully received !

The only way to really check is to borrow a run out gauge. This is a magnetic tool that clamps itself to the strut. Protruding from it is a needle that rests against the disc leading to a gauge that will record the variance as you pass the disc through a full 360 degree rotation. These tools are common place.
You may get an indication by just passing the disc through the rotation and seeing if it is tight at any stage.
Hope this helps.
You may get an indication by just passing the disc through the rotation and seeing if it is tight at any stage.
Hope this helps.
The judder might not be due to warping - see here www.stoptech.com/tech_info/wp_warped_brakedisk.shtml
Juddering brakes aren't always caused by worn discs or pads. It may just be that the surface isn't impregnated evenly. If it isn't too bad you may be able to clear it just by going through the bedding-in procedure again. I have a set of GreenStuff pads which are very abrasive when they are hot, which come in very handy for cleaning up the brake discs if I have been driving gently for too long. But if things are looking well worn then replacing the pads/discs is a sensible thing to go.
The discs you need are standard plain production discs (not drilled/grooved etc). The pads are NOT standard production pads, you need good quality fast road pads. If your motofactor tries to tell you that their standard pads are just as good, don't believe them.
There's no special trick to replacing discs and pads if you don't mind getting your hands dirty. The fronts are the easiest because you don't have to worry about the handbrake mechanism.
You will need to unbolt the caliper to remove the disc. Be carefull to support the weight properly and don't let it pull on the hose.
Get some brake cleaner and clean all the brake dust and grease off the outside of the caliper where the pads bear (and the rest of the caliper if you are feeling keen). Also use this to clean the protective coating off the new discs before fitting.
Clean and regrease the sliders while you have the caliper off, and check they work smoothly.
You will need to push the piston back to fit the new pads. This will push fluid back into the reservoir; make sure it doesn't over flow. It normally won't, but as your pads wear the reservoir level will go down, and if somebody has been overzealous and kept topping it up then it will overflow when you put the new pads in.
When you refit the calipers, use temporary (breakable) threadlock on the bolts. You may even find the new pads come with a set of new bolts with the threadlock pre-applied.
After you finish each corner, apply the brakes a couple of times to seat the pads. If you don't do this then when you push the next caliper in it will probably overflow the reservoir. This also prevents any scary 'no brakes' moments the first time you drive off.
Ideally bleed the brakes while you were at it.
After you've done this, you will need to bed the new pads and discs in. The pads will come with instructions to do this. It is worth taking the time to read and follow them because the instructions do vary, and some pads don't work at all well until they are bedded in properly.
The discs you need are standard plain production discs (not drilled/grooved etc). The pads are NOT standard production pads, you need good quality fast road pads. If your motofactor tries to tell you that their standard pads are just as good, don't believe them.
There's no special trick to replacing discs and pads if you don't mind getting your hands dirty. The fronts are the easiest because you don't have to worry about the handbrake mechanism.
You will need to unbolt the caliper to remove the disc. Be carefull to support the weight properly and don't let it pull on the hose.
Get some brake cleaner and clean all the brake dust and grease off the outside of the caliper where the pads bear (and the rest of the caliper if you are feeling keen). Also use this to clean the protective coating off the new discs before fitting.
Clean and regrease the sliders while you have the caliper off, and check they work smoothly.
You will need to push the piston back to fit the new pads. This will push fluid back into the reservoir; make sure it doesn't over flow. It normally won't, but as your pads wear the reservoir level will go down, and if somebody has been overzealous and kept topping it up then it will overflow when you put the new pads in.
When you refit the calipers, use temporary (breakable) threadlock on the bolts. You may even find the new pads come with a set of new bolts with the threadlock pre-applied.
After you finish each corner, apply the brakes a couple of times to seat the pads. If you don't do this then when you push the next caliper in it will probably overflow the reservoir. This also prevents any scary 'no brakes' moments the first time you drive off.
Ideally bleed the brakes while you were at it.
After you've done this, you will need to bed the new pads and discs in. The pads will come with instructions to do this. It is worth taking the time to read and follow them because the instructions do vary, and some pads don't work at all well until they are bedded in properly.
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