Uneven brake disc wear - one side only

TomTheTyke · 6th April 2024, 16:25

Hi all,

As per the title, I was swapping my Summer wheels back on yesterday and noticed that my drivers side front brake disc had worn unevenly on the inside face, as though the pad had only been making contact on about 2/3 of the disc on that side, leaving a slight but noticeable ridge / lip.

Other braking surfaces all fine.

My current provisional diagnosis is the pad probably sticking in the caliper, since the piston seems to be working as the pads are obviously acting on part of the disc. Does that seem sensible? It's probably worth cleaning and re-greasing the sliders as well.

I'll get to that pending better weather.

Secondly, if it is the pad can I free it off, clean & grease and leave it there? Will they progressively wear in more evenly or do I need to replace the pad(s) / disc(s)?

SD1too · 6th April 2024, 18:31

Quote:

Originally Posted by TomTheTyke

My current provisional diagnosis is the pad probably sticking in the caliper ... Does that seem sensible?

It could be, yes. The castings corrode readily. Yesterday I wire brushed and greased my OSR caliper after noticing the aroma of overheating brake linings when refilling with fuel.

Quote:

Originally Posted by TomTheTyke

... if it is the pad can I free it off, clean & grease and leave it there?

You'll need to make that judgement after examining the friction material's condition Tom. The same goes for the disc.

Simon

TomTheTyke · 7th April 2024, 19:00

Thanks Simon.

The disc doesn't seem too bad, as I said the lip/ridge is slight but noticeable. I would therefore hope still serviceable.

Fair point on the friction material. Hopefully I'll get to it one night this week now we have the light for longer.

Ed3 · 8th April 2024, 07:43

As a DIY amateur on my 06 CDTi I have replaced all of my brake calipers. 2 new on the rear (£30 each) and s/h on the front as a quick cheap way (eg £20) to get going.

As strictly DIY amateur approach I work on the basis that due to age the piston gets dirty and will stick. So I constantly check each wheel for heat after driving or look for more road dirt than other wheels.

xsport · 8th April 2024, 17:59

Quote:

Originally Posted by TomTheTyke

Thanks Simon.

The disc doesn't seem too bad, as I said the lip/ridge is slight but noticeable. I would therefore hope still serviceable.

Fair point on the friction material. Hopefully I'll get to it one night this week now we have the light for longer.

If the calipers are sticking due to dirt ,then you can almost guarantee that the insides of the calipers are filthy. Dirt and swarf and alloy accumulates throughout the system and fluid over time. I would think the fluid needs fully changing and it is the most important aspect of brakes maintenance. Once done i bet you will have a good run of free easy working brakes ,after you have done your cleaning and inspections of the caliper/carriers functions ...

TomTheTyke · 9th April 2024, 18:25

Thanks for the advice all.

Fluid is well within its' 2 year life, having only been replaced in July of last year according to my records. This was when I replaced rear discs and pads. Fronts were done (also by me so the below is no doubt my error) in May 2022.

I did have the brake apart and inspect yesterday. I think the inner pad itself may not have been fully clipped into the piston, one of the three 'prongs' I think was not seated properly, and it tried to pop back out again as I replaced the pad. I think this may have been causing it to contact the disc when running and wear unevenly, but only on the small section where the pad was 'sticking out.'

Anyway, there is plenty of meat left on pad and disc, all are now clipped in properly, cleaned and regreased so I'll keep an eye on it from here.

See photos:

https://ibb.co/4YcpyY1

https://ibb.co/YNJCgVK

6th April 2024, 16:25	#1
TomTheTyke Avid contributor Rover 75 2.5 Connoisseur, MG TF 80th Anniversary Join Date: Sep 2021 Location: Pontefract Posts: 157 Thanks: 12 Thanked 22 Times in 11 Posts	Uneven brake disc wear - one side only Hi all, As per the title, I was swapping my Summer wheels back on yesterday and noticed that my drivers side front brake disc had worn unevenly on the inside face, as though the pad had only been making contact on about 2/3 of the disc on that side, leaving a slight but noticeable ridge / lip. Other braking surfaces all fine. My current provisional diagnosis is the pad probably sticking in the caliper, since the piston seems to be working as the pads are obviously acting on part of the disc. Does that seem sensible? It's probably worth cleaning and re-greasing the sliders as well. I'll get to that pending better weather. Secondly, if it is the pad can I free it off, clean & grease and leave it there? Will they progressively wear in more evenly or do I need to replace the pad(s) / disc(s)?

9th April 2024, 18:25	#6
TomTheTyke Avid contributor Rover 75 2.5 Connoisseur, MG TF 80th Anniversary Join Date: Sep 2021 Location: Pontefract Posts: 157 Thanks: 12 Thanked 22 Times in 11 Posts	Thanks for the advice all. Fluid is well within its' 2 year life, having only been replaced in July of last year according to my records. This was when I replaced rear discs and pads. Fronts were done (also by me so the below is no doubt my error) in May 2022. I did have the brake apart and inspect yesterday. I think the inner pad itself may not have been fully clipped into the piston, one of the three 'prongs' I think was not seated properly, and it tried to pop back out again as I replaced the pad. I think this may have been causing it to contact the disc when running and wear unevenly, but only on the small section where the pad was 'sticking out.' Anyway, there is plenty of meat left on pad and disc, all are now clipped in properly, cleaned and regreased so I'll keep an eye on it from here. See photos: https://ibb.co/4YcpyY1 https://ibb.co/YNJCgVK Last edited by TomTheTyke; 9th April 2024 at 18:28..

7th April 2024, 19:00	#3
TomTheTyke Avid contributor Rover 75 2.5 Connoisseur, MG TF 80th Anniversary Join Date: Sep 2021 Location: Pontefract Posts: 157 Thanks: 12 Thanked 22 Times in 11 Posts	Thanks Simon. The disc doesn't seem too bad, as I said the lip/ridge is slight but noticeable. I would therefore hope still serviceable. Fair point on the friction material. Hopefully I'll get to it one night this week now we have the light for longer.

8th April 2024, 07:43	#4
Ed3 Loves to post Rover 75 CDTi saloon Join Date: Nov 2017 Location: UK Posts: 306 Thanks: 88 Thanked 29 Times in 26 Posts	As a DIY amateur on my 06 CDTi I have replaced all of my brake calipers. 2 new on the rear (£30 each) and s/h on the front as a quick cheap way (eg £20) to get going. As strictly DIY amateur approach I work on the basis that due to age the piston gets dirty and will stick. So I constantly check each wheel for heat after driving or look for more road dirt than other wheels.