Uneven brake pad wear?

[discodan]

Today I noticed that the brake pads on my left brake disk are quite a bit more worn than the ones on the right. As far as I can tell, they are wearing evenly for the same disc but for some reason the pads on the left disk have about 1.5mm less pad left. EBC HH pads and I had the brakes bled last time I changed the pads.

This is for an SV650 race bike btw so the pads do take a fair beating.

Has anyone encountered this before? I don't mind changing both sets but I'm guessing there is something wrong for them to be so different.

[discodan]

I just took the calipers off and got some photos. It looks like only one of the pads is more worn than the others, which is even more strange to me :wacko:


111538

111539

[sAsLEX]

Path of least resistance.

Are all the pistons and the whole assembly nice and clean?

[Subike]

Are your caliper slides working OK?

[discodan]

Path of least resistance.

Are all the pistons and the whole assembly nice and clean?

I have never cleaned them so maybe that is it. Not sure how to go about giving them a good clean though.


Are your caliper slides working OK?

Yea, from what I can tell. The performance seems fine, I only noticed a problem when I checked the wear.

[Squiggles]

Does each caliper have a line from the master? or does the LHS piggy off the Right

[discodan]

Does each caliper have a line from the master? or does the LHS piggy off the Right
There is one line from the master cylinder that splits in two for each caliper. Both sides are definately getting used, is it possible one of the brake pads is defective? You can't really see from the photos but it even looks like it is chipped on the edges.

[quickbuck]

Today I noticed that the brake pads on my left brake disk are quite a bit more worn than the ones on the right. As far as I can tell, they are wearing evenly for the same disc but for some reason the pads on the left disk have about 1.5mm less pad left. EBC HH pads and I had the brakes bled last time I changed the pads.

This is for an SV650 race bike btw so the pads do take a fair beating.

Has anyone encountered this before? I don't mind changing both sets but I'm guessing there is something wrong for them to be so different.


Let me guess,
You do most laps at Manfeild??

My CBR did the same. Went through a full set by Lunch time on a Training day!
Yep, cooked them. LH inboard was to the metal.

I put it down to the fact that you are always turning into a RH corner with the picks still on at Manfeild....
Oh, you may have spent a bit of time at Taupo, but that is far more economical on brakes.

Hope this helps, and would be keen to hear from others who do lots of laps at Manfeild to prove or disprove my theory.

[sAsLEX]

I have never cleaned them so maybe that is it. Not sure how to go about giving them a good clean though.





I used CRC Brakleen or something like that and a tea towel/rag. Got rid of most of the gunk and crap that had built up and left me with nice shiny pistons.

Push them in with your fingers and check they move freely.

[xwhatsit]

I put it down to the fact that you are always turning into a RH corner with the picks still on at Manfeild....
Surely this would only be the case if your wheel bearings were majorly fucked? Even if it was down to fork flex, there would be very little movement in the angle of the caliper compared to the disc.

[JMemonic]

An aerosol brake cleaner is a start, it looks to me like there is only pistons on one side of the caliper so the slides might be gummed up, if you can get hold of the workshop manual it should help give you an idea of what to do.

If not:

1 Clean the calipers thoroughly compress the pistons back.

2 Disassemble the calipers, if you look at the calipers carefully you will find that the non piston side will have a set of slides that come away from the piston assembly.

3 Clean the slide up, a little time spent here is worth it as you will check each slide for damage pits etc.

4 Reassemble the caliper, now here is the trick, its called grease, yes I know its near your breaks but hold off the worry for a moment, head to a local brake shop and ask them for a recommendation on what to use, grease the slides up and we are talking such a light coat of grease that well it might seem you had not done it at all but the entire shafts are covered in this manner thus there is none to come of onto you rotors.

5 Put in the new pads and assemble onto the bike, squeeze the lever a few times to see how the assembly moves and to get you pads in the right places that they will work.

Easy wasnt it, just take your time dont try to be in a hurry and figure out how it all works.

[discodan]

Let me guess,
You do most laps at Manfeild??

My CBR did the same. Went through a full set by Lunch time on a Training day!
Yep, cooked them. LH inboard was to the metal.

I put it down to the fact that you are always turning into a RH corner with the picks still on at Manfeild....
Oh, you may have spent a bit of time at Taupo, but that is far more economical on brakes.

Hope this helps, and would be keen to hear from others who do lots of laps at Manfeild to prove or disprove my theory.

You are right, I do spend most of my time at Manfeild so that would explain it but I can't see how it would wear down one brake pad so much more.


An aerosol brake cleaner is a start, it looks to me like there is only pistons on one side of the caliper so the slides might be gummed up, if you can get hold of the workshop manual it should help give you an idea of what to do.

If not:

1 Clean the calipers thoroughly compress the pistons back.

2 Disassemble the calipers, if you look at the calipers carefully you will find that the non piston side will have a set of slides that come away from the piston assembly.

3 Clean the slide up, a little time spent here is worth it as you will check each slide for damage pits etc.

4 Reassemble the caliper, now here is the trick, its called grease, yes I know its near your breaks but hold off the worry for a moment, head to a local brake shop and ask them for a recommendation on what to use, grease the slides up and we are talking such a light coat of grease that well it might seem you had not done it at all but the entire shafts are covered in this manner thus there is none to come of onto you rotors.

5 Put in the new pads and assemble onto the bike, squeeze the lever a few times to see how the assembly moves and to get you pads in the right places that they will work.

Easy wasnt it, just take your time dont try to be in a hurry and figure out how it all works.

Good advice, I'm gonna buy some brake cleaner and make it my project for the evening. Cheers to everyone who has replied, at least I know that it is not normal and will get it checked out.

[Max Preload]

I used CRC Brakleen or something like that and a tea towel/rag. Got rid of most of the gunk and crap that had built up and left me with nice shiny pistons.

Don't clean brake calipers with aerosol brake cleaners. I know it sounds ridiculous considering it's "brakeclean", but it is detrimental to the rubber components, most importantly the piston dust seals and slide boots. Read the label on the can. Use only a soapy water to clean your calipers and then rinse them off thoroughly with clean water.


4 Reassemble the caliper, now here is the trick, its called grease

Rubber grease. And certainly never a copper based anti-seize.

Also, pay attention to the seat on the caliper where the pad sits - that's what takes the load, so ensure it's smooth so that the pads aren't catching when the brake is applied reducing the pressure on one end of the pad (trailing) causing excessive tapered wear to the leading edge.

Uneven pad wear on a floating caliper arrangement like yours is usually sticky caliper slides, either from lack of lubricaton or worn pins.

[stify]

Don't clean brake calipers with aerosol brake cleaners. I know it sounds ridiculous considering it's "brakeclean", but it is detrimental to the rubber components, most importantly the piston dust seals and slide boots. Read the label on the can. Use only a soapy water to clean your calipers and then rinse them off thoroughly with clean water.



Rubber grease. And certainly never a copper based anti-seize.

Also, pay attention to the seat on the caliper where the pad sits - that's what takes the load, so ensure it's smooth so that the pads aren't catching when the brake is applied reducing the pressure on one end of the pad (trailing) causing excessive tapered wear to the leading edge.

Uneven pad wear on a floating caliper arrangement like yours is usually sticky caliper slides, either from lack of lubricaton or worn pins.

I've been using brakeclean products in me line of work for 20 odd years(mechanic),I've never had an issue with it affecting rubber brake components, just make sure your pistons are cleaned before they are pushed back(bike piston seals aren't as gd at keepin da shit out as car ones are)as for using rubber grease on sliders(with rubber bushings) if it's not high temp grease don't bother(it will end up solid and cause the rubber sliders to stick to your brake slider pins), and as max said, don't use copper based anti seize compound on brake components(esp in sliders as it will seize up-funny that aye) from the look of your pads and the type of calipers/plumbing you have, uneven wear is normal to a certin extent, as for the chipping, it's poss that the pads have been overheated

[imdying]

Max is correct, brakeclean isn't strictly suitable for rubber components.

[JMemonic]

Rubber grease. And certainly never a copper based anti-seize.


I did suggest heading to the local brake shop for the correct advise, no I would not use copper slip or copper coat, or any copper based grease, nor would I use rubber grease, its umm water based and can cause seizure and corrosion.

Oil would be fine but it wears off hence the grease, a good grease with a bit of molly in it Valvoline M, Castrol LMM, Fuchs LXM02 etc and the coating you will give is so thing as to be practically invisible.

If in doubt always get your brakes seen to buy qualified people at your local brake service outfit, they might not have the pads on the shelves but the understand how they work and how to service any faults.

Oh a foot note copper based greases are anti seizure compounds and as such are not meant for load type use they are just to stop things corroding together, nickel based grease is the same for high temp applications. Not all greases are the same and have different applications.

[imdying]

Use something like Wurth brake paste... it's goes a long way.

[discodan]

I have taken the pistons out and given them as good a clean as I can with the brake cleaner. I noticed one of the dust seals stuck out a bit when I extended the pistons with the brake lever, this could have been part of the problem.

I'm getting a new piston kit and seals soon so not worried about the rubber degrading at the moment but I will look into some grease for the sliders. All good information and I have learnt a fair bit about the brakes on my bike, which is good.

[FROSTY]

In your situation I'd suggest not just cleaning the pistons but POLISHING them. Not with a cutting compound --just get that chrome all shiney.
From My POV if you can reduce brake drag its got to be worth HP to you

[Max Preload]

...nor would I use rubber grease, its umm water based and can cause seizure and corrosion.

Righto. Best that you immediately inform Castrol (http://www.castrol.com/castrol/productdetailmin.do?categoryId=9000448&contentId=7000520), Fuchs (http://www.opieoils.co.uk/p-999-fuchs-renolit-red-rubber-grease-grease-for-use-on-elastomers.aspx), PBR (http://www.allraceoil.com/pbrrubbergrease.html) & all the other manufacturers of the error of their ways. There's a good lad.

[JMemonic]

Righto. Best that you immediately inform Castrol (http://www.castrol.com/castrol/productdetailmin.do?categoryId=9000448&contentId=7000520), Fuchs (http://www.opieoils.co.uk/p-999-fuchs-renolit-red-rubber-grease-grease-for-use-on-elastomers.aspx), PBR (http://www.allraceoil.com/pbrrubbergrease.html) & all the other manufacturers of the error of their ways. There's a good lad.

I read piston seal on all of those not umm calliper slides but that's just me, I am only remembering what I was taught as an apprentice, if you have issue like I said go to your local brake servicing company and ask for their advise, also I have seen these greases jam up calliper slides, never seen it happen with the greases I mentioned, but that's just me.

[JMemonic]

In your situation I'd suggest not just cleaning the pistons but POLISHING them. Not with a cutting compound --just get that chrome all shiney.
From My POV if you can reduce brake drag its got to be worth HP to you

Good point Frosty, sometimes the contaminants can cause pitting or form a varnish around the piston you can miss this with just cleaning with brake cleaner and such like solvents.

Just out of interest how often do you change the fluid on a race bike? I know in normal usage its recommended two years but if this is a race bike, the fluid takes a hammering and as its your safety we are taking about I would consider every oil change, it cheap insurance really.

[FROSTY]

Could wafle on about what ya "should" do or whatever. truth is unless changing it for other reasons I change fluid once a season at beginning of season.