Brake pad life - what's to be expected

[EricV]

Re: fast rear brake pad wear

Can answer that straight off. No or minimal residual spin. Never have had that with this bike from day 1. Some hiss from the rear when turning it, but have never given it a second thought assuming slight pad contact. I have limited hands on with this bike because you have to let dealer take care of routine service to maintain Yam warranty in my country. BTW, my dealer doesn't know what a TBS is and why it would be done in the first place. That's a by-the-way that I am keenly aware of. So, interested to pursue this as I think my rear pad wear has been too fast based on life of first set of pads. I have a 2010 First Edition by-the-way...


...or mountain out of a mole hill... I did get 14.4k miles out of the outer rear pad. Take away 1000 miles for when I should have replaced it.

Sometimes the piston builds up a ring of gunk on it and won't fully retract. Typically this takes years for a street bike, but for a dual-sport, it's possible to occur faster. This can cause what you describe. Disassembly of the caliper and careful cleaning of the piston if you can visibly see build up, will solve this. Non abrasive cleaning methods!

The high temp silicone brake grease is good stuff. Typically I use a very small amount between the pad backs and the anti-rattle shims, and a healthy amount on the pins that mount the caliper to the bracket, which as Don said, allow the caliper to float back and forth and self center as you apply the brakes. I also use a small amount on the outside of the anti-rattle shims where they interact with the piston and bracket. I've never used it where the pads fit into the caliper at the 'notches'. Not called for there and I don't see a benefit, but do see it potentially attracting dirt and causing issues.

 

[Don in Lodi]

Re: fast rear brake pad wear

Sometimes the piston builds up a ring of gunk on it and won't fully retract. Typically this takes years for a street bike, but for a dual-sport, it's possible to occur faster. This can cause what you describe. Disassembly of the caliper and careful cleaning of the piston if you can visibly see build up, will solve this. Non abrasive cleaning methods!

Do these pistons not have a rubber dust boot? Being open to atmosphere doesn't seem right.

 

[markjenn]

Re: fast rear brake pad wear

Do these pistons not have a rubber dust boot? Being open to atmosphere doesn't seem right.

I haven't seen a motorcycle disc brake yet with any kind of dust protection like the bellows that car brakes have.

- Mark

 

[Don in Lodi]

Re: fast rear brake pad wear

Thanks. All these years and I never really paid attention...

 

[RMac]

Re: fast rear brake pad wear

According to the manual there is a dust seal ring around the piston, internal to the caliper that should prevent crap getting in, but otherwise no protective boot or anything like that. When I installed the new pads I was easily able to push the piston back with my thumbs. It moved freely and smoothly.

My thinking about this is leaning towards possible excess residual pressure on rear pads due to the way the linked brake system works rather than having a specific issue with a rear brake caliper component. I have no proof on the other hand.

 

[sail2xxs]

Re: fast rear brake pad wear

My rear brake pads needed to be replaced at 20K miles. Fronts still have close to 65% remaining, bike has 33k on it now. It is unusual for me to need rear brake pads quite so soon, and I wonder if time in the dirt has anything to do with this. I've noticed that the venting holes in the brake rotors, especially the rear, tend to fill up with dirt/road/trail dust after you've been off pavement for a while. 20-30 miles of gravel road, and the rear is plugged up. My guess is that the pads wear more quickly as they pull a little bit of dirt out of the vents in the rotor, and grind it on the rotor when you use them. Anybody else notice this?

Chris

 

[EricV]

Re: fast rear brake pad wear

Perhaps I can explain better. I'm not talking about dirt getting inside the dust seal. As the pads wear, the piston stays farther out, beyond the dust seal. What I have seen is a ring of crud build up on the piston area that stays outside the dust seal. As RMac said, he was able to easily push it back in, so in his case, it would appear that this may not an issue. Especially at low mileage.

On the FJR, I didn't replace the pads until 90k and a bit longer on the rear. I did need to do some serious cleaning on both front and rear calipers when I replaced the pads. It's not that I couldn't have pushed the pistons in, but it would not have been good for the seals. I did see uneven wear on the pads, both from a left to right pad comparison and a top to bottom taper.

The calipers were simply not sliding evenly under braking and the piston may not have been fully retracting, due to the crud build up.

I would want to make sure the system was bled well. Any air bubbles would expand as the system heated up and could cause issues. I'd also want to verify that the master cylinder reservoir was not over filled and was clean. Usually there is a small hole that allows fluid to re-circulate and pressure to drop when the lever/pedal is released. I haven't looked on the S10, but have seen this get clogged on auto versions and cause the brakes to not only drag, but get so bad that the calipers wouldn't release fully and pads were quickly worn away, rotors damaged from excess heat, etc.

If you haven't already done so, a complete flush and bleed of the system with new DOT 4 brake fluid would be a Good Idea™.

 

[RMac]

Re: fast rear brake pad wear

During the 20k service my dealer said that brake fluid had absorbed quite a lot of moisture and should be replaced at 30k service. I will go over your suggestions when I get some time and will probably change fluid in the process.

 

[Epping]

Re: fast rear brake pad wear

Found this in a review of the Super Tenere:

Brakes are linked front-to-rear, so the hand lever automatically activates both front and rear brakes, while the foot pedal only activates the rear brake. The linked system adjusts the ratio of front to rear braking by comparing lever pressure to the rate of deceleration; if a lag is detected due to greater weight (like a passenger, or cargo), more pressure is directed towards the rear brake.


So it would seem that there would be more wear on the rear brake pads if you carry a heavier load. (no scale needed )

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I have mentioned the front brake bite is not what I would expect. I reckon the culprit is the front pads. If the system reads the poor retardation as a heavy load and applies more rear brake then we have our answer. The solution (& proof ) would be to fit high performance or metallic pads to the front only for extra front brake performance. I only have 10k km so fronts not needed but I will check what alternatives are available & do an early swap.

 

[DinX]

Re: fast rear brake pad wear

Found this in a review of the Super Tenere:

Brakes are linked front-to-rear, so the hand lever automatically activates both front and rear brakes, while the foot pedal only activates the rear brake. The linked system adjusts the ratio of front to rear braking by comparing lever pressure to the rate of deceleration; if a lag is detected due to greater weight (like a passenger, or cargo), more pressure is directed towards the rear brake.


So it would seem that there would be more wear on the rear brake pads if you carry a heavier load. (no scale needed )

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Sounds logical.

So it's a sign that I should lose some weight, not that I'm braking too much (220lb) )

 

[snakebitten]

fast rear brake pad wear

Sounds logical.

So it's a sign that I should lose some weight, not that I'm braking too much (220lb) )

I'm not skipping one single Chocolate Chip Cookie just to save on rear brake pads.
Have you had the CCC's from Subway?


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[EricV]

Re: fast rear brake pad wear

Sounds logical.

So it's a sign that I should lose some weight, not that I'm braking too much (220lb) )

I agree that it sounds plausible, but I weigh 250 w/o gear and carry a heavy load of crap, panniers always on and usually full since I use the bike to travel. And my pads are perhaps only half worn at 26k. Just a data point. I do seem to brake less than other people though. ::001::

 

[RMac]

Re: fast rear brake pad wear

I weigh 220lbs myself.

That aside, I haven't been on the bike for a couple of days now, so I took her out for a quick and rather spirited run this evening. Before hitting the road I put the bike on the centre stand and spun the back wheel. Despite what I indicated earlier I get at-least a half to 3/4 of continued turn on the rear wheel after releasing it and otherwise feels quite free without undue resistance. The run itself involved quite a lot of hard acceleration and braking. When I got home the front brake rotors were only slightly warm, but the rear rotor was too hot to touch. So, up on the centre stand again and the rear wheel spun even more freely than at cold, so minimal residual brake pad resistance. The entire rear wheel actually felt warm to the touch, but I think that this is due to heat transmission from the final drive which was quite toasty after my run. Not too hot to touch, but hot. Like I said it was a very spirited run. Not really any further forward on this one. I have no baseline to go on. In other words, it is only since I changed my rear brake pads that I have started to feel the rear rotor to see how hot it gets.

 

[jajpko]

Re: fast rear brake pad wear

I weigh 220lbs myself.

That aside, I haven't been on the bike for a couple of days now, so I took her out for a quick and rather spirited run this evening. Before hitting the road I put the bike on the centre stand and spun the back wheel. Despite what I indicated earlier I get at-least a half to 3/4 of continued turn on the rear wheel after releasing it and otherwise feels quite free without undue resistance. The run itself involved quite a lot of hard acceleration and braking. When I got home the front brake rotors were only slightly warm, but the rear rotor was too hot to touch. So, up on the centre stand again and the rear wheel spun even more freely than at cold, so minimal residual brake pad resistance. The entire rear wheel actually felt warm to the touch, but I think that this is due to heat transmission from the final drive which was quite toasty after my run. Not too hot to touch, but hot. Like I said it was a very spirited run. Not really any further forward on this one. I have no baseline to go on. In other words, it is only since I changed my rear brake pads that I have started to feel the rear rotor to see how hot it gets.

If you were using the brakes a lot the rear will be hot. The front brakes will cool better and faster. As long as there is no discoloration or heat checks, it should be good.
If you were able to touch the final drive and hold your hand on it, that sounds right.

It's just my opinion but it sounds like it's all good.

 

[dcstrom]

Re: fast rear brake pad wear

If you were using the brakes a lot the rear will be hot. The front brakes will cool better and faster.

Yeah, I just did a few miles getting on the front brake lever pretty hard, not touching the rear. Got home, sure enough the rear is very hot, front hot but cooler. I'm pretty sure I don't like that. As an ex-roadracer, when I'm braking hard on the front, I want the weight to transfer to the front so I can brake even harder. I don't care about the rear except maybe a gentle touch to keep things in line. Certainly don't want equal power on the rear as appears to be happening with UBS on the S10.

I still reckon I can stop faster on the Vee - given a good surface of course. Anything other than that, the S10 ABS would kick my arse!

 

[jajpko]

Re: fast rear brake pad wear

Yeah, I just did a few miles getting on the front brake lever pretty hard, not touching the rear. Got home, sure enough the rear is very hot, front hot but cooler. I'm pretty sure I don't like that. As an ex-roadracer, when I'm braking hard on the front, I want the weight to transfer to the front so I can brake even harder. I don't care about the rear except maybe a gentle touch to keep things in line. Certainly don't want equal power on the rear as appears to be happening with UBS on the S10.

I still reckon I can stop faster on the Vee - given a good surface of course. Anything other than that, the S10 ABS would kick my arse!

I really don't care for the linked system either. I had it on my Wing and didn't like it then. I do like the ABS though. One good thing about this bike, is if you use the rear first, it will unlink. So if you can get use to tapping the rear brake before the front, the rear will not get as hot...

 

[EricV]

Re: fast rear brake pad wear

Hmm, page 1-8 in the shop manual states: "NOTICE - Because the balance between the front brake calipers and the rear brake caliper in the unified brake system is determined electronically, be sure to use the specified brake pads."

This makes me wonder if you can 'tweak' the system to your tastes by running different compounds front and rear. I.E. EBS red one end, EBC green the other, for example.

Also worth noting is that the coefficient for rear to front pressure is set when you apply the brakes, and will remain constant until the brakes are released. In other words, hammer the brakes at high speed, (front or front first, then rear), and it will pressurize the rear brake high, and leave it high until you release the brakes, even while you continue to slow down. Let off, it will re-asses when you next apply the brakes and since you have slowed down, likely apply less pressure coefficient to the rear brakes. "The UBS brake force does not decrease together with vehicle speed."

It's not a simple thing to eliminate the UBS. The brake lines are the same for the ABS, but the linking is more electronic than physical. There is one line running from the master cylinders to the ABS block, and one line running out from the ABS block to the calipers, (for each end). In there somewhere is an electronic circuit that makes the UBS work. I will spend some time looking at the system and see if there is an easy cheat to defeat the UBS, but I suspect it's buried in the ECU.

 

[dcstrom]

Re: fast rear brake pad wear

It's not a simple thing to eliminate the UBS.

Maybe there's a switch under the front brake lever where we can insert a fuse? ::025::

 

[EricV]

Re: fast rear brake pad wear

::013:: ::013:: ::013:: ::013::

 

[RMac]

Re: fast rear brake pad wear

Found it! To unlink the UBS you put a short across the battery terminals....

I assume no responsibility for damage that may occur if you try this ::024::