Replacing pads and disks

bmw528i

Strider590 wrote: »

On modern cars, the discs are just as "consumable" as the pads, changing both is relatively normal. Running new pads into old discs can impair braking performance substantially.

the discs are still well within the minimum specs, why change something just for the sake of it?

Jonesya

If you decide to do it yourself, to make for an easy life I'd say buy yourself a copy of the service manual, I've done this for a couple of cars I've owned and it makes jobs much easier, plus it gives you the confidence you're doing it correct as it covers all the steps and gives you info like torque settings.

Also, I'd say buy the brake pad accessory kit, this lets you replace the consumables with new - caliper clips, slide pin boots, grease and (depending on your car) the single-use bolts that ought to be replaced.

Strider590

bmw528i wrote: »

the discs are still well within the minimum specs, why change something just for the sake of it?

Because pads and discs wear with eachother, any grooves/scoring will match the disc to the pads. When you change just the pads, the new pads are flat, but the discs have scoring/grooves, so might only actually get 50% pad to disc contact for the first hundred miles or so AND this uneven contact will cause heat spots on the pad and disc, which could glaze the new pads or even crack the disc due to heat stress.

Does that answer your question?

Gloomendoom

s_b wrote: »

of course on something like germanys finest engineering merchandise like an up then its also feasible that pushing the caliper pistons back sends the abs unit into meltdown if one was to say rush it or worse not know what ones doing

True, but isn't just Germany's finest, and is easily countered by opening the bleed nipple while pushing back the caliper so that the fluid is not forced backwards through the ABS modulator.

You do need to ensure that no air is drawn back into the caliper in the process and remember to top up the master cylinder reservoir with fresh brake fluid.

s_b

Gloomendoom wrote: »

True, but isn't just Germany's finest, and is easily countered by opening the bleed nipple while pushing back the caliper so that the fluid is not forced backwards through the ABS modulator.

You do need to ensure that no air is drawn back into the caliper in the process and remember to top up the master cylinder reservoir with fresh brake fluid.

and then the OP comes back with
ive put the spanner on the bleed nipple thingy me bob and its broken off and fluids coming out how do i rectify this can i use bluetack etc


see post 30 below.......

of course on something like germanys finest engineering merchandise like an up then its also feasible that pushing the caliper pistons back sends the abs unit into meltdown if one was to say rush it or worse not know what ones doing
i always think brain surgery just like brakes are best left to those that do it for a living
messing with an old viva on a sunday afternoon and breaking stuff to see how to fix it is perfectly ok though as it doesn't need to go down the M4 tommos