Uneven brake pad wear

[germ]

I did my front brakes today (103 kmi) after hearing noises from the front right wheel for a couple of weeks. I found that one pad on the front right was worn all the way through. But its companion and the pads in the front left still have about 3-4 mm left.

Is this normal?

[Zombie_Head]

Brake caliper piston maybe sticking a bit and not returning to its proper position.

Could be numerous other reasons such as brake master cylinder, but that is in extreme cases. Did the piston go back into the caliper all the way easily when you replaced the pads? did you see any signs of cracked seals, leaking seals? cracked piston or even corrosion?

[MightyMouseTech]

Originally Posted by germ

I did my front brakes today (103 kmi) after hearing noises from the front right wheel for a couple of weeks. I found that one pad on the front right was worn all the way through. But its companion and the pads in the front left still have about 3-4 mm left.

Is this normal?

This is pretty normal.

BMW says brake servicing is not required. But, the pads will get stuck in the carriers after a while.

I usually pull them apart, clean the pads and lube every once in a while.

[Zombie_Head]

Originally Posted by MightyMouseTech

This is pretty normal.

BMW says brake servicing is not required. But, the pads will get stuck in the carriers after a while.

I usually pull them apart, clean the pads and lube every once in a while.

That is possible as well, pads could be "sticking" on the carriers.

[germ]

Originally Posted by Zombie_Head

Brake caliper piston maybe sticking a bit and not returning to its proper position.

Could be numerous other reasons such as brake master cylinder, but that is in extreme cases. Did the piston go back into the caliper all the way easily when you replaced the pads? did you see any signs of cracked seals, leaking seals? cracked piston or even corrosion?

Yes, the pistons did go back all the way into the caliper after a lot of pushing. It was hard to get the new pads apart enough to fit on the new rotors. It's possible only if the pistons are all the way in.

I checked the pistons and they look good. Nothing like the pics you see online...

[chris_flies]

Sounds relatively normal. I have F30 335i brakes on my 128i (4 piston Brembos, similar to the 135i brakes) and there is a little uneven pad wear (maybe a mm difference inside to outside) after a track day (probably the grease I applied breaking-down and becoming ineffective in the heat).

Not nearly as bad as my dad's Mk7 GTI and the OE pads. The pads were so tapered after just one day (not even a weekend), that there was almost a cm difference from one end of the pad to the other, and they were so incredibly chunked-up (his look was a little priceless after he saw them lol). Now he's converted to the Porterfield R4 and R4-S rotation regime that I use and love. They are really good pads...

[rowsdower]

Originally Posted by chris_flies

Sounds relatively normal. I have F30 335i brakes on my 128i (4 piston Brembos, similar to the 135i brakes) and there is a little uneven pad wear (maybe a mm difference inside to outside) after a track day (probably the grease I applied breaking-down and becoming ineffective in the heat).

Not nearly as bad as my dad's Mk7 GTI and the OE pads. The pads were so tapered after just one day (not even a weekend), that there was almost a cm difference from one end of the pad to the other, and they were so incredibly chunked-up (his look was a little priceless after he saw them lol). Now he's converted to the Porterfield R4 and R4-S rotation regime that I use and love. They are really good pads...

I've heard you mention pad swaps are easy on the F30 brakes. Do you have to unbolt the caliper or do the pads slide out with it still attached? And what are your rear calipers, also F30 335i or 128i?

My calipers (remanned, installed last year and run in a saltless environment) are already covered in rust so I'm trying to figure out what I want to do with my brakes. F30 335i sound great, just expensive. I might just clean up the 128i calipers and paint them.

[chris_flies]

Originally Posted by rowsdower

I've heard you mention pad swaps are easy on the F30 brakes. Do you have to unbolt the caliper or do the pads slide out with it still attached? And what are your rear calipers, also F30 335i or 128i?

My calipers (remanned, installed last year and run in a saltless environment) are already covered in rust so I'm trying to figure out what I want to do with my brakes. F30 335i sound great, just expensive. I might just clean up the 128i calipers and paint them.

Oh my goodness. Pad swaps are SO EASY! Pop guide pins out, pull pads out, push pads in, pop guide pins in. Done. Maybe some greasing and cleaning in the middle, but that's the idea. No unbolting calipers, no replacing slider pins, etc.

I've got stock 128i rear brakes, the brake balance doesn't feel wonky, and the stopping power is phenomenal (far greater than the tires can support right now).

All the stock front brakes really need are some good pads, rotors, and fluid. That made the single biggest difference for me (combined with the nanny coding). I could finally haul myself down at the end of a long straight with total confidence. I believe that the 130i/330i had aluminum calipers vs our iron ones, as well as larger rotors, but I'm not 100% sure on that.

[juld0zer]

The other explanation is DSC and driving style/frequented roads' surface/condition.

My 130i has iron calipers.

[Zombie_Head]

Originally Posted by chris_flies

Oh my goodness. Pad swaps are SO EASY! Pop guide pins out, pull pads out, push pads in, pop guide pins in. Done. Maybe some greasing and cleaning in the middle, but that's the idea. No unbolting calipers, no replacing slider pins, etc.

I've got stock 128i rear brakes, the brake balance doesn't feel wonky, and the stopping power is phenomenal (far greater than the tires can support right now).

All the stock front brakes really need are some good pads, rotors, and fluid. That made the single biggest difference for me (combined with the nanny coding). I could finally haul myself down at the end of a long straight with total confidence. I believe that the 130i/330i had aluminum calipers vs our iron ones, as well as larger rotors, but I'm not 100% sure on that.

I know you do not need anything in the rear, but you can install the caliper from the E9x 325i (328i for USA). They are bolt on, same size but the piston is 2mm larger. It is the same one you get when ordering the Performance brakes front and rear.

The 130i/330i carriers are heavy bastards, i think they are iron not aluminum. Stock calipers and good pads/fluids with bigger 130i/330i made a huge difference in stopping power, maybe the F30 front calipers will be swapped in the future, unsure, i have seen race cars running stock calipers and bigger front discs without issues. The calipers on the 130i and 125i are the same, just the carriers and discs, up to the E9x 320i. E9x 325 and 330i have different calipers.

[Mr Gasser]

the caliper assembly is sticking, don't know how much of an auto nerd you are, but they need to be either replaced or rebuild to specs and then bleed the system with dot 4 synthetic...and go with ceramic pads imo leaves no brake dust on wheels.

[Zombie_Head]

One more thing, people that did the brass caliper guides are reporting huge increase in both pedal feel and stopping force, since the caliper(s) are not twisting (or twisting less).

This is definitely something i will be doing before any kind of "big brake" change.

[chris_flies]

Originally Posted by OnerDriver

The similarity between the F30 and 135i is that they are fixed calipers, not sliding as on the 128i. The 135i has a 6-piston Brembo though, as opposed to 4.

I'm sure you meant the pads wore 1mm, not cm as they don't have that much worth of material from new to completely worn.

Those VW pads have a ton of material on them. There was a 1cm difference from one end to the other

[chris_flies]

Originally Posted by OnerDriver

So the pad was done after 1 weekend? Pads don't normally have 1 inch of thickness...

There's about 11mm (1.1cm) of total pad thickness on those pads new. And, FWIW, there are 2.54cm (25.4mm) in an inch.

One side of the pads was pretty much the thickness of a new pad, and one side was worn down to about 1mm remaining, hence the 1cm difference.

[Suprgnat]

Originally Posted by chris_flies

There's about 11mm (1.1cm) of total pad thickness on those pads new. And, FWIW, there are 2.54cm (25.4mm) in an inch.

One side of the pads was pretty much the thickness of a new pad, and one side was worn down to about 1mm remaining, hence the 1cm difference.

Funniest part of this thread is the 'Murican lecturing the Canadian on the Metric System.

[chris_flies]

Originally Posted by Suprgnat

Funniest part of this thread is the 'Murican lecturing the Canadian on the Metric System.

I wasn't going to go there

[Suprgnat]

Originally Posted by Zombie_Head

One more thing, people that did the brass caliper guides are reporting huge increase in both pedal feel and stopping force, since the caliper(s) are not twisting (or twisting less).

This is definitely something i will be doing before any kind of "big brake" change.

I wouldn't and don't own sliding caliper brakes without them. Still have them on my rears. PM me and I'll send you a gently used set (off my old fronts), free, on my dime. What do you have to lose?

[Zombie_Head]

Originally Posted by Suprgnat

I wouldn't and don't own sliding caliper brakes without them. Still have them on my rears. PM me and I'll send you a gently used set (off my old fronts), free, on my dime. What do you have to lose?

I will be contacting you about this, would like the rear brass bushings as well.

Give me a week or so to sort out some things, this month has been a bit heavy on me.

[germ]

Originally Posted by Mr Gasser

the caliper assembly is sticking, don't know how much of an auto nerd you are, but they need to be either replaced or rebuild to specs and then bleed the system with dot 4 synthetic...and go with ceramic pads imo leaves no brake dust on wheels.

Where did you get the parts? O-rings, piston, dust boot cover?

[Mr Gasser]

https://www.ecstuning.com/b-stoptech...ach/143.34031/