BoxheadTim (Forum Supporter)
BoxheadTim (Forum Supporter) MegaDork
12/28/20 7:10 p.m.

Tried to figure out why I heard a bit of a grinding noise when I push my '92 Goldwing around. Both calipers were clamping on the rotors nicely when I tried to pull them off so it felt like they're a bit seized or at least the pistons don't retract as much as they should. However the crowning glory was this:

The "stuff" that's on the top left edge of the brake pad appears to be melted pad material, or at least pad material that has reconstituted itself. You can also see that the edge of the pad seems to be delaminating.

The pad on the other side doesn't look quite as bad, but also has material at the edge of the friction material that looks like it got squeezed out of the pad.

Anybody want to hazard a guess as to what happened here? Cheapo brake pads not designed for the weight of the bike? Bad calipers? Someone sticking pins into an effigy of my bike? Message from my guardian being that I need to buy a Harley instead?

stuart in mn
stuart in mn MegaDork
12/28/20 7:20 p.m.

It may simply be due to age, if they are as old as the bike.

AngryCorvair (Forum Supporter)
AngryCorvair (Forum Supporter) MegaDork
12/28/20 7:34 p.m.

I doubt that it melted or otherwise reconstituted, but I wouldn't be surprised if the pad material delaminated from the shoe plate (likely due to corrosion) and got wedged in place.

I will second age and maybe a little bit of the damage was caused from oxidation of the rotor being captured and creating a very hot spot on the pad causing further delamination. 

A guess.

BoxheadTim (Forum Supporter)
BoxheadTim (Forum Supporter) MegaDork
12/28/20 7:44 p.m.

I would be very surprised if these pads are the original ones - the bike has 40k on the odometer and while some people manage to make the pads last that long I would expect them to have hardly any friction material left. These look about 1/2 worn.

I'll pull them out tomorrow if I can get the locator pins out and have a closer look. Maybe they are just aged out as the bike hasn't seen that much use the last few years before I bought it and I didn't put that many miles on it in the last couple of years either. 

BoxheadTim (Forum Supporter)
BoxheadTim (Forum Supporter) MegaDork
12/28/20 7:46 p.m.

In reply to QuasiMofo (John Brown) Forum Supporter :

Given that the pads seem to be dragging more than they should IMHO, they may have had more heat in them in the last couple of rides than they should have. 

BoxheadTim (Forum Supporter)
BoxheadTim (Forum Supporter) MegaDork
12/29/20 2:12 p.m.

Quick update - definitely not the original pads. It's still not quite clear to me what the material is that is accumulating at the edge of the brake pads. Chatted with a friend of mine who's put over 100k on one of these bikes and he suggested going either with OEM or EBC pads - apparently he's not a big fan of the aftermarket brand that's in there and has issues with them before.

Next fun job will be to disassemble the read of the bike to get at the rear caliper and see if this one has similar problems.

BoxheadTim (Forum Supporter)
BoxheadTim (Forum Supporter) MegaDork
12/29/20 7:45 p.m.

Ah yes, I'll quickly check the rear brake caliper...

... after disassembling about a third of the bike, that is.

 

Good news, the brake pads in the rear are in much better shape. Of course they're also a completely different brand, which speaks well for how the bike's been maintained.

44Dwarf
44Dwarf UberDork
1/17/21 8:15 a.m.

EBC, SBS make great pads I've been very impressed with SOK pads on several bikes even my race bikes and there are low cost.

The goo is likely brake dust and road grime as the drag increased the pad outgasses and collected every bit of debris that came by.

Nice bike!

wvumtnbkr
wvumtnbkr PowerDork
1/17/21 8:54 a.m.

I've seen shmutz like that on my mountain bike brake pads.  Usually from riding through super soupy trails.  It is a mashup of vegetation, mud, etc that gets baked onto the pads.

 

Maybe the same thing here?

914Driver
914Driver MegaDork
1/17/21 11:07 a.m.

That kinda happened on my R-90, not that extreme though.  Seems the piston did it's job but didn't fully retract, water in the fluid made rust in the cylinder.

Now I see why my Saab 900 manual says to flush and change the brake fluid annually.

BoxheadTim (Forum Supporter)
BoxheadTim (Forum Supporter) MegaDork
1/17/21 11:59 a.m.
44Dwarf said:

EBC, SBS make great pads I've been very impressed with SOK pads on several bikes even my race bikes and there are low cost.

The goo is likely brake dust and road grime as the drag increased the pad outgasses and collected every bit of debris that came by.

Nice bike!

Thanks. The pads on the bike were actually SBS in the front and EBC in the back. My "GoldWing guru" friend has had issues with SBS in the past on his GL1500, although he thinks they may have been fakes.The consensus from him and a bunch of GW forums so far seem to be to stick with OEM or EBC. I have to order some other OEM parts for this bike so I'm going OEM all around.

Appleseed
Appleseed MegaDork
1/17/21 12:00 p.m.

That color is tits, btw 

BoxheadTim (Forum Supporter)
BoxheadTim (Forum Supporter) MegaDork
1/17/21 12:04 p.m.
914Driver said:

That kinda happened on my R-90, not that extreme though.  Seems the piston did it's job but didn't fully retract, water in the fluid made rust in the cylinder.

Now I see why my Saab 900 manual says to flush and change the brake fluid annually.

The bike has had very regular fluid changes, fortunately. The PO (and his step dad, from whom he inherited the bit) were both pretty good about basic maintenance and including the brake fluid.

That said, the front caliper pistons at least don't look that friendly. They're pretty dirty and feel extremely stiff when trying to push them back. I'm planning on cleaning them thoroughly before pushing them back into the caliper, but depending what I find I may have to buy a couple of caliper rebuild kits.

A lot of manufacturers recommend 2 year intervals on brake fluid on cars, and IIRC BMW even recommends a one year interval on some bikes with the servo brakes.

BoxheadTim (Forum Supporter)
BoxheadTim (Forum Supporter) MegaDork
1/17/21 12:06 p.m.
Appleseed said:

That color is tits, btw 

One definitely doesn't have to guess the time period that bike was built in .

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