How much is left on these brakes?

[Calza]

Appreciate that it's very much down to the driving style, but I'm clueless so can't even hazard a guess. 2013 C63 if it makes a difference.


Front OS:



Front NS:



Rear NS:



Rear OS:

[E-bmw]

Now check the inner pads as there will likely be a difference between inner & outer.

[Aunty Pasty]

Not a lot I'd say. I'll say there's probably just a few thousand miles left on them if that. I guess from the rust it hasn't been driven recently. The disks do show definite signs of heavy wear so They're all due soon IMO.

[Smint]

Between 10 and 20k driven normally, maybe sooner for the fronts, pretty sure you can still see the tapered ends of the rear pads in one of the pics so only half worn.

Are they the second set of pads on those discs because quite a wear ridge building up, time for new discs when the pads are changed.

Edited by Smint on Saturday 9th October 19:46

[aterribleusername]

I'd be looking to change those at the earliest opportunity on a normal car, let alone on something like a C63.

[stevieturbo]

It depends on driving style, but they are due replacement anytime.

Not a big deal unless you're planning a few thousand mile road trip around the Alps though.

[GreenV8S]

Looks like the pads are about 75% worn. The discs don't look great and I'd look to replace those when replacing the pads, but nothing there looks bad enough to worry about in the short term.

ETA: Hard to judge how long it's been standing from the surface rust, but if it's > 12 months the fluid may not be in great shape either. I wouldn't want to drive it hard unless/until I'd checked or flushed the fluid.

[Calza]

Appreciate the replies, a bit mixed but mostly seems that replace soonish but not urgent.

It had been washed and standing for a week or so as far as I can tell.

[voram]

Smint said:

Between 10 and 20k driven normally, maybe sooner for the fronts, pretty sure you can still see the tapered ends of the rear pads in one of the pics so only half worn.

Are they the second set of pads on those discs because quite a wear ridge building up, time for new discs when the pads are changed.

Broadly this - but as someone's already said, what about the pads you can't see?

[nickfrog]

I agree, plenty of road miles, at least 10k. I would use vernier calipers to measure the thickness of the discs or get a local garage to do it and then compare to the OE wear spec. I agree that the discs might need binning with the old pads.

[Calza]

Garage have advised they will replace them if:

Pads are >50% worn
Discs are excessively lipped or own (i.e an MOT advisory).

Are we likely to tick both those boxes?

[Smint]

I'll bet they will, kerching, replacing brakes when just under half worn is a good policy for early retirement for them.

Yes the front are just under half worn, depending how you drive pads could last 30k from new or up to 80k typically, so anything from 10k to 30k potentially left.
Discs have an obvious lip, and no one would fit new discs and put worn pads back in.

Course if you're buying this car and they are going to replace all pads and discs as part of the sale deal at no cost to you, then by all means let them carry on.
The rears possibly will be not yet half worn and the wear lip not yet noticeable enough, appraisal of those might depend on who's wallet is being hit.

From the looks of the discs, pads need to come out and the brake calipers cleaned lubed (correctly) and 'exercised' regardless of whether new friction materials are fitted.

[voram]

Calza said:

Garage have advised they will replace them if:

Pads are >50% worn
Discs are excessively lipped or own (i.e an MOT advisory).

Well, that's the classic guidance given by new car dealers whose customers are probably driving 20,000 miles a year and don't want to faff about at the garage more than once a year.

Half worn. Is your glass "half full" or "half empty"?

I'd say it was half full.

[HustleRussell]

Pads on the not-too-distant. 5,000 miles or so from what I can see.

Discs may well go again, I don't see any sign of deep scoring or heavy wear so it'll come down to measuring them.

[stevieturbo]

The discs do not look particularly worn.

The pads are well below 50%, and usually the inner will be worn more than the visible outer.

[23.7]

stevieturbo said:

usually the inner will be worn more than the visible outer.

I know this is so, but why?

[Smint]

On MB's there's no reason for the inners to be worn more, they are usually opposed piston calipers either 2 or 4 piston, so long as maintained regularly the pistons should exert equal force on all pads, unlike calipers of the sliding design which do tend to wear one pad more than than its opposite.

Sliding piston calipers in theory should exert equal pressure to both pads also, but given the typical long term neglect most owners give to their braking systems (not helped by non existant preventative maintenance by most make's service schedules) once sliders start to run dry and seize and pads get stuck in place, then unever wear takes place.

Just swapped front pads out on a Civic today, neglected as most are, sticking slider and pads so jammed in place no retraction was happening, due to that seizing slider 1 pad in particular was worn much more than the other 3

Recent experience with under 20k miler Golf mk 6 rear brakes, ruined disc one side due to stuck caliper slider due to once again non existant maintenance other than dealer inspection which included non removal of pads or even the wheel with the usual brake cleaner being squirted liberally about, all in all about much use as pre heating a chocolate teapot.

[nickfrog]

Smint said:

On MB's there's no reason for the inners to be worn more, they are usually opposed piston calipers either 2 or 4 piston, so long as maintained regularly the pistons should exert equal force on all pads, unlike

Cheers. What maintenance should be done?
Cleaning/sanding of the pins? New seals? Anything else?

Asking for the Clio's 12 years old Brembos!

[Smint]

nickfrog said:

Cheers. What maintenance should be done?
Cleaning/sanding of the pins? New seals? Anything else?

Asking for the Clio's 12 years old Brembos!

Pads out obviously and clean everything up.

If there are sprung stainless clips fitted to the caliper which grip the pads gently and allow the pads to slide along gradually as they wear, its best to ping them off and give them a good wire brushing all over and clean the caliper castings where they sit of any build up of crud or corrosion, then refit, you'll find the pads go back in a lot easier than they came out.

If reusing the same pads worth giving the edges a wire brushing of any rust, some people give a wipe of coppalip to the back of the pads, but if you do this where the pistons contact that c'slip will contact the piston dust covers and gradually weaken them, again brake grease for that purpose, you could if you wished apply a little coppaslip to the enges of the pad backing plates where they contact the caliper...if they have the aforementioned stainless clips to slide against that shouldn't be necessary, but can help to lessen any tendency to high frequency vibration which causes squealing.

Coppaslip should only be used sparingly where metal touches metal, not where it can come into contact with rubber, instead buy a 500ml tub of the correct red brake grease, this tub will last you a lifetime, clean slide pins regrease and put back in.

Push pistons home gently...some people insist on opening the bleed valve to push them back in, citing danger of flipping master cylinder seals, been pushing them back gently for near on 50 years and it hasn't happened yet, not saying it can't of course but doing the push back gently will minimise any possibility.
If you find pushing the pistons home is stiff, then once you've got them in get an assistant to press the brake pedal half way a few times to push the pistons out an inch at most, you could do this a few times ''exersing'' the pistons in their bores, when out its permissable to lift the dust cover gently to check the piston itself for corrosion, it's also permissable to feed a little real brake grease into the piston itself, i use a cotton bud for this purpose if e.
After a few times it should be easy pushing the pistons home.

I use a massive pair of water pump type pliers for pushing pistons back in, they are variable and open up to something like 4" with some 2ft of leverage, can grip round the outside of the caliper and push the piston home gently and evenly.

Note...when exercising the pistons, work on one side at a time, leaving the other brakes fully assembled, it would be too easy to be pushing the piston out you are working on and the one the other side you forgot about plops out on the floor.
Dual pistons are easier for exercising, with suitable levers you can push one in with the other sliding out multiple times without touching the pedal.

Whilst down there even if you arn't going to bleed the brakes it won't do any harm to just crack the bleed nipple and retighten, more likely not to snap or round off when your eventually do flush the fluid out.

Inspect flexible pipes and any steel solid brake pipes, no harm at all in giving steel pipes a coat of grease.

I've heard of people using angle grinders to take out wear lips on discs, never done this myself, if carefully bought discs are so cheap now just not worth messing about with in my opinion.

Sure i've missed something glaringly obvious out, and happy to be corrected if anyone thinks this method is wrong.

[nickfrog]

^^wow. Thank you so much for taking the time, appreciated. That's what I really like about PH.