Hi everyone, I'm trying to work out if my brake pads need replacing. I've been driving this car for a few years now and thought maybe it's time to replace the brake pads. But on visual inspection of the pads it looks as though it's not worn out as much as I thought it would be. Since I've never done brake pads before I have posted a picture of the brake pads for you guys for an opinion - see pic https://imgur.com/a/BgFaM1d
How to Inspect Brake Pads for Replacement?
MuddyClear on 19/09/2019 - 11:25
Last edited 19/09/2019 - 11:37 by 1 other user
Last edited 19/09/2019 - 11:37 by 1 other user
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sorry about that. I thought you can add a picture directly on ozb forum but it seems you can't, so i used imgur. You should be able to see it now.
Plenty of stopping left, FYI- you can inspect without removing them.
I also wanted to check the rotors as when I brake on highway I noticed a lot of vibration on the steering wheel - but the rotor thickness looks even…
@MuddyClear: What car?
Set up a pencil or marker on a brick so it doesn't move and rotate the disc to determine the runout.
Pulsing can also be caused by hotspots due to overheating the rotor or from uneven material transfer from the pad to the rotor.
It could also be caused by worn bushes / tie rods / ball joints or a really bad wheel alignment.
Do you get a pulsing pedal? Under light braking does it appear to grab then let go again?
@brad1-8tsi: Sorry don't know how to quote on here so doing this:
Q: Do you get a pulsing pedal?
A: Yes when slowing down for lights on highway driving - not at all in city/suburban driving.Q: Under light braking does it appear to grab then let go again?
A: Yes. I have noticed when I suddenly brake hard on the rare occasion.@MuddyClear: It's hard to diagnose without a visual inspection / road test but most of the time these days it's uneven material transfer.
Read this:
https://www.powerstop.com/what-causes-brake-pedal-pulse-vibr…and this:
http://archive.naplesnews.com/community/dr-johnnys-car-clini…and this:
https://www.fremax.com.br/en/artigo/63/curing-brake-pulsatio…RockyRaccoon is also somewhere near the money as to a possible cause. You've probably reached the limits of internet diagnosis at this point.
You never said make/model/year of vehicle. A photo of the rotor might help too.
@MuddyClear: This doesnt mean your pads or rotors are worn out, it can mean your rotors are warped, which can occur if you have had some very hard braking experiences.
Do a google search on warped rotors and your car model, that will also show if this might be a issue that your car can suffer from
There is a site that has discussions on this issue and various opinions on how it caused, albeit its overheated rotors in some way that causes the issue
@MuddyClear: The disc might need machining. check with a brake specialist. Also this cause degradation in brake performance.
@apple2016: I’m leaning towards a warped rotor at this stage but I will need to confirm this. It seems it’s cheaper to replace a rotor (<$100 diy) than have it machined at auto shop ($100).
@MuddyClear: Get plain face DBA rotors from Brakes Direct. If you are going to do rotors then do the pads too. You'll get all the bits for <$200.
Ring them and have a chat about what pad suits your driving style.
They are fine.
My rule of thumb for customer cars is to change them when the friction material thickness is less than the backing plate thickness. This is more to do with heat transfer and the possibility of the pad falling out than anything else. Personally, I don't give my brakes a hard time (I don't tow or drive like a nob) so I take them down to about 2mm.I'd suggest you check the inner pad as sometimes they wear unevenly.
As you have them apart, clean up the pads and calipers, lube the slider pins and any metal-on-metal contacts and you'll be good for a while yet.
If it's been 3+ years then consider getting the brake fluid flushed.
You can. In settings, under Files tab.
when you hear screeching sound of metal on metal
https://www.apecbraking.co.uk/getattachment/Resources/Techni…
https://www.bestbeginnermotorcycles.com/wp-content/uploads/2…
nah that's too soon.
sparks gotta fly
thats too early, just wait till your brakes actually fail. even then who cares
ah yes, the standard tree magnetism test.
if you end up wrapped around a tree then it's time to change the brake pads.
@cynicalmike: I always wait until the steering wheel starts heating up when I put the brakes on. Then it’s change pads time. Works for me.
@Ozpit: i wait until i'm literally surrounded by flames and a red character is poking a pitch fork in my butt.
then i mildly consider thinking about changing my brake pads.
@cynicalmike: That's really playing with fire. Just don’t ever make any deals with that pitch fork guy.
i don't hear a screeching sound yet.
In this link, the grooves aren't wear indicators. They are for anti-squeal. I've even cut them in manually on persistent squealers.
https://www.bestbeginnermotorcycles.com/wp-content/uploads/2…
I beg to differ. The groove is a wear indicator. Wear indicators are usually either a pin in the backing material or a sheet metal type scratcher, an electric contact or grooves exactly like what is in that photo. While I agree that cutting grooves in pads does alleviate most brake squeals, this is not their primary function. It's usually for wear indication, expansion and heat dissipation.
OP's photo shows no scratcher or pin, and no wiring (although these could be on the other pad), so the groove could be for determining serviceability. (or in the case of Bendix, a printed "replace" section
Good rule to follow is, if the braking material is thinner than the metal backing plate, it's time to change them.
Source: I've changed more brake pads in my life than I've had hot breakfasts… and wikipedia… and Racing Brakes… and Brake Magazine… and too many others to list…
I appreciate all the links and your experience. I appreciate what they are saying but that means some pads would need changing at ~6mm. I did think Brake Magazines comment "help clear the mud" funny.
And I would have done as many brakes as you have. That's all I did for 5+ years. Brakes and alignments for 50 hours a week.
@brad1-8tsi: I did like the Bendix take on wear limits though. We don’t usually buy in Bendix, but ironically, had a customer bring their own in on Friday for fitting and had a look at them. No groove at all and the marking;
▒ ▒ ▒ REPLACE ▒ ▒ ▒
Even the apprentice could work that one out…
@pegaxs: I'm not a fan of Bendix either.
Could you see that printing without removing the caliper?
I've got to say that I like the Wagner/DBA combination I put on the rear of the Octavia. 90% reduction in dust. Work well from cold. No noise.
OTOH, I put Bremtec Trade Series (on Brakes Direct recommendation) on the Accord Euro and the dust is really bad and the pedal is wooden. Not happy. I wish I would have got the ceramics.
Could you see that printing without removing the caliper?
Not really. And with the amount of dust Bendix usually makes, it would be obscured in a short time anyway. Or maybe not. These were their new "titanium stripe" ceramic pads, So I'll be keen to do a followup to see what they are like. But at least the customer bought DBA rotors, so it's got that going for it, which is nice…
Usually when the pads are 1/4" thick or less is the recommended time to replace them.
If you don't drive in the city with constant stop start driving or wait until the last minute to slam on your brakes up to 100k is achievable before replacement is required. YMMV.
6mm is a bit early - especially on the rear where there might only be 8mm to start with.
What's going on with this forum and the use of imperial measurements?
plenty of meat there
Look like they're barely run in. Replace when friction material gets down to a couple of mm.
Surprises me because I have driven the car for a few years.
Haven't been braking much then, have you? :)
Maybe it's a hybrid.
Have you checked front and back? Both sides?
That's nearly a brand new pad, at least another 50k, how much bur do you feel on the rotors?
A lot. It scared me when driving downhill at high speeds (~100km/hr) and apply brakes when coming to traffic lights. The steering wheel would shake like crazy. It seems you need a specialize tool to check for warped rotors. I think i'm just going to replace them at this stage.
I used to replace the front disk rotors on my previous car when I felt the pedal move a bit. I used to tow a van. I used to buy rotors at Repco and Super Cheap. Much better to buy than get them machined. Then can do all the work myself. No worries about the rotors getting to thin either.
It's cheaper too. MyCar/Kmart Auto want to charge me $100 for machining when I can get a new one for less than that, especially when there's a sale on.
Do you need to bleed the brakes if you do it yourself?
I would check the front end for wear, especially ball joints
How are the engine mounts?
If you do get new discs, change the pads at the same time & grease the wheel bearings properlyWhat causes the vibration is thickness variations in the rotor. These are caused by long term intermittent contact of the pad on the same spot. Some cars are more sensitive but if you have more than 15 micron difference between thin spot and thickest spot then you will probably feel it. This is 0.015 mm about thickness of a hair Runout on its own will not cause vibration as the caliper just slides across to accommodate it. This is why machining is a very temporary fix as without a very accurate machine there will be at least 10 microns thickness variation introduced by the machining. OEM will not tolerate more than 3 micron dtv and typically try to keep rotor runout to less than 20 microns. The notion that you can check this with a pencil is laughable and severely misinformed. Buy new rotor and pads and make sure rotor mount face is spotlessly clean and that the pads are a loose sliding fit in the anchors. Don't use grease as this will catch the grit and clog the slides. For low duty driving Japanese friction material is better as it puts a film on the rotor and you get close to zero rotor wear. This film gets damaged by the intermittent contact of the pad which is where the dtv sets in. jap cars have good dust shields to keep abrasive road dirt out. Excellent money saving work in making your brakes last 200,O00 km
Do I need to buy new pads if replacing new rotor as my front pads still look new?
I would buy new pads as well, as the pads can get abrasive dust into them from the road. They sometimes wear tapered and while they look new you'll probably get a better outcome with new ones. for low duty use you are better with something like Bendix CT as these are non-asbestos organic and will put a film on the rotor. They get friction from the stickiness of the pad to this film and not by cutting the rotor to shreds (look in thier sales material for info as they do several pad material types). You will get minial dust as well. Avoid paying a premium for 'performance pads' as these are very unkind to rotors but work better at high duty levels, in hilly country or if you were pulling a big trailer or caravan,
Pads from the honda dealer will be expensive but be careful as they are often not true OEM parts and are just aftermarket pads in a honda box. They often call the factory pads 'warranty pads' as they only do this if they are fixing up a fault under warranty. If you can get proper OEM pads then so much the better, but it seems like you are careful with the brakes anyway.
Aftermarket pads won't last as long as the OEM parts, probably a third to a half of your 200k but you'll get same performance and hopefully low noise from squeal.
My question is, at what speed is the vibration? and how severe is it? It may be something else. Cars have a common issue at around 80km/h when slowing down where an out of balance front wheel can give a severe vibration in the steering wheel that seems to come in at around 80km/h and then disappear as you slow down more.
A severe vibration or feedback through the steering wheel is not always brakes. Its more likely suspension, bearing or tyre related. Brake issues tend to feedback through the pedal or cause a linear jerking/bumping sensation, not so much a "vibration"
If you are feeling a pulsing in the pedal, this is the sign of a worn rotor or a warped rotor.
And like most have said on here, those pads are ok. The gap in the middle is the wear indicator. What you need to do is check the thickness of your discs. Or, for the price of them, just replace them if you are replacing the pads anyway.
There's no picture…