Author Topic: Front brakes - left pad worn much more than right pad - rebuild?  (Read 273 times)

Offline Kookas

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So, my front wheel makes a rubbing sound and only spins one revolution with a hard push. I can see I need new brake pads and I should refresh the fluid, but I think I might have to rebuild the brakes. All that salty winter riding, I guess.

The left brake pad has worn a lot more than the right one. This means perhaps the guide pins, right?

Trouble is, it's an 07 GS500F and I can't find a single seal kit. How did you other F owners deal with this? I've heard of swapping the caliper for an SV one?

Weird situation, really, when the 90s GS500Es have so much more parts support than the newer models! I guess the Fs never took off like the Es.

Worth mentioning I'm based in the UK.
« Last Edit: April 14, 2018, 06:32:18 PM by Kookas »

Offline J_Walker

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Re: Front brakes - left pad worn much more than right pad - rebuild?
« Reply #1 on: April 15, 2018, 01:35:14 AM »
interesting. hard to tell what you mean by left and right, take a picture, use postimg website to host image, post image on here for us to see.
-Walker

Offline The Buddha

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Re: Front brakes - left pad worn much more than right pad - rebuild?
« Reply #2 on: April 15, 2018, 02:20:01 AM »
The garbage design of the caliper puts all the wear on the static pad, AKA the inner pad, aka the left pad.
Since my switch to katana FE the 4 pads wear out so slowly on the thing its ridiculous and they all wear equally. The miracle of dual disks and DOP's.
Cool.
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Offline Kookas

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Re: Front brakes - left pad worn much more than right pad - rebuild?
« Reply #3 on: April 15, 2018, 11:54:00 AM »
Here are photos:

This is the inner pad, with just a couple of mm left:


And this is the outer pad, with what looks like plenty of life in comparison:


I've already ordered some pads and new fluid and am going to take this off (and hopefully clean the bike too!) next weekend but am not sure if I can get the parts to do the job properly.
« Last Edit: April 15, 2018, 12:00:00 PM by Kookas »

Offline The Buddha

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Re: Front brakes - left pad worn much more than right pad - rebuild?
« Reply #4 on: April 15, 2018, 04:01:04 PM »
There is no cleaning and rebuilding and poosy footing around garbage design bro.
2 pistons on 1 side and a "bracket" on the other = shiteteyety design.
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Offline Kookas

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Re: Front brakes - left pad worn much more than right pad - rebuild?
« Reply #5 on: April 15, 2018, 04:39:40 PM »
So, decided I'd just order in an SV650 caliper and a steel brake line whilst I was at it. All-in-all, 100 this will cost me, but it'll be worth it if it means I can rebuild it cheaply in future and anyway the brake lines are probably as old as the bike.

Wish I could just swap the front-end, but I'd probably swap the whole bike before getting around to that!
« Last Edit: April 15, 2018, 04:40:18 PM by Kookas »

Offline alpo

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Re: Front brakes - left pad worn much more than right pad - rebuild?
« Reply #6 on: April 15, 2018, 05:33:55 PM »
Lots of bikes have pistons on only one side of the caliper. All my dirt bikes do and they have pretty even pad wear.
So, my front wheel makes a rubbing sound and only spins one revolution with a hard push. <snip>
The left brake pad has worn a lot more than the right one. This means perhaps the guide pins, right?
You're on to something with the guide pins.  With the brakes binding the wheel from turning and the excessive wear on your left pad I bet the caliper is not moving like it should. I'd take it apart and clean/grease those guide pins. Make sure the caliper slides smoothly on them and goes all the way to the left.

Offline Kookas

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Re: Front brakes - left pad worn much more than right pad - rebuild?
« Reply #7 on: April 15, 2018, 05:40:13 PM »
Lots of bikes have pistons on only one side of the caliper. All my dirt bikes do and they have pretty even pad wear.
So, my front wheel makes a rubbing sound and only spins one revolution with a hard push. <snip>
The left brake pad has worn a lot more than the right one. This means perhaps the guide pins, right?
You're on to something with the guide pins.  With the brakes binding the wheel from turning and the excessive wear on your left pad I bet the caliper is not moving like it should. I'd take it apart and clean/grease those guide pins. Make sure the caliper slides smoothly on them and goes all the way to the left.

Do you think there's a chance I'll get away with keeping the seals? I'm thinking if I take the caliper off and find I don't need the SV one I can return it.

Offline alpo

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Re: Front brakes - left pad worn much more than right pad - rebuild?
« Reply #8 on: April 15, 2018, 06:03:45 PM »
Do you think there's a chance I'll get away with keeping the seals? I'm thinking if I take the caliper off and find I don't need the SV one I can return it.
Assuming the caliper was dragging the left pad produced a lot of heat, but brakes are designed to take a lot of abuse. Since the right pad is not worn as much the pistons are moving. As long as it's not leaking you should be OK.

The seals are not difficult to replace if needed. You can use the hydraulic pressure from the line to push the pistons out - just go slowly, so they both come out together. A C-clamp on top of a piece of wood can be used to push the pistons back into the caliper.

Offline Kookas

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Re: Front brakes - left pad worn much more than right pad - rebuild?
« Reply #9 on: April 15, 2018, 06:46:19 PM »
Do you think there's a chance I'll get away with keeping the seals? I'm thinking if I take the caliper off and find I don't need the SV one I can return it.
Assuming the caliper was dragging the left pad produced a lot of heat, but brakes are designed to take a lot of abuse. Since the right pad is not worn as much the pistons are moving. As long as it's not leaking you should be OK.

The seals are not difficult to replace if needed. You can use the hydraulic pressure from the line to push the pistons out - just go slowly, so they both come out together. A C-clamp on top of a piece of wood can be used to push the pistons back into the caliper.

It's not so much the difficulty as the fact that I can't source any replacement seals for this front caliper anywhere. Replacement seals for SV calipers, on the other hand, are a dime a dozen.

About the heat, though, it doesn't actually seem to be that bad, strangely. I took this bike to go and pick something up from the other side of the city and to do my shopping - about 20 miles or so total - and when I got back, I touched the disks with my bare hands (after testing the water with gloves on, of course!) and they were completely touchable. This was in pouring rain, though. I've also been getting 52 mpg (British units, think that's 43 US mpg) so it's clearly not causing too much drag.

Of course, I have been engine braking and keeping those braking distances up knowing my pads don't have much time left! It's my only private transport so it's got to make it through the next 120-odd miles this week, although I've no death wish so I'm prepared to take the train if the pads disappear before Friday.
« Last Edit: April 15, 2018, 06:51:48 PM by Kookas »

Offline alpo

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Re: Front brakes - left pad worn much more than right pad - rebuild?
« Reply #10 on: April 15, 2018, 08:01:00 PM »
They're a bit more expensive in the UK than the US, but here's one source I found:
Brake Caliper Seals Suzuki GS500 2006-08 (Front)

Were it me I'd just clean up the caliper, put new pads in, bleed it good and see how it works.

Offline Kookas

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Re: Front brakes - left pad worn much more than right pad - rebuild?
« Reply #11 on: April 15, 2018, 08:13:12 PM »
They're a bit more expensive in the UK than the US, but here's one source I found:
Brake Caliper Seals Suzuki GS500 2006-08 (Front)

Were it me I'd just clean up the caliper, put new pads in, bleed it good and see how it works.

Oh nice one! Guess I should've Googled a little better, I didn't know about that site before - think I'll order those instead then. Cheers.

Offline gregjet

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Re: Front brakes - left pad worn much more than right pad - rebuild?
« Reply #12 on: April 15, 2018, 09:07:39 PM »
On single piston brakes it is common for brake pads to wear more on one side than the other if the bike is subject to repeated heavy braking enough for the pads to get and stay hot. The design means one side runs cooler than the other ( not always the same side for different calipers and dependant on operating temperature of the pad material).
Just one of the reasons dual side piston brakes are preferable.
However check and clean the pins that allow the pads to float and polish them if possible .Don't put any lubricant on them as it will attract dirt and brake dust and they will no longer float properly and self level.
« Last Edit: April 15, 2018, 09:10:14 PM by gregjet »

Offline alpo

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Re: Front brakes - left pad worn much more than right pad - rebuild?
« Reply #13 on: April 15, 2018, 10:52:46 PM »
Don't put any lubricant on them as it will attract dirt and brake dust and they will no longer float properly and self level.
Not true.

Each pin is covered in a rubber boot. A light coat of synthetic grease will keep them working smoothly.

If the boots are torn they should be replaced.

Offline gregjet

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Re: Front brakes - left pad worn much more than right pad - rebuild?
« Reply #14 on: April 17, 2018, 08:33:02 PM »
"Each pin is covered in a rubber boot. A light coat of synthetic grease will keep them working smoothly. "
I refer to the pins retaining the pads. They have no boot and run through the holes in the pads. The pads run along them on the piston side with each stroke and the static pad stays still. I have seen people put ordinary grease on them which them melts and contaminates the pad ( there is always one).
Hyosungs were notorious for having them wear/corrode and stick.
 If you put lube on them they collect dirt and brake powder and can seize the pad movement.

Offline Kookas

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Re: Front brakes - left pad worn much more than right pad - rebuild?
« Reply #15 on: April 17, 2018, 09:11:01 PM »
Grease the booted ones and not the exposed ones, got it!

Offline alpo

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Re: Front brakes - left pad worn much more than right pad - rebuild?
« Reply #16 on: April 17, 2018, 10:43:33 PM »
I refer to the pins retaining the pads.
Gotcha. Those pins should be installed dry. We were discussing the caliper guide pins, which need a little lube.

Offline Kookas

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Re: Front brakes - left pad worn much more than right pad - rebuild?
« Reply #17 on: April 21, 2018, 04:38:30 PM »
So as usual, I started this job to find I had no clue what I was doing whatsoever.

I didn't remove the pistons with them on the bike, so have ordered a tool.

I took the calipers off and pads out, but I'm not sure which way I need to turn the nuts on the guide pins to remove them?

Actually, nevermind that. Googled some pictures of guide pins and realised they just slide out. Now I just need to clean them up and grease them, then tomorrow I'll get the pistons out with the tool and hopefully finish the job. 

Weirdly though it actually looks like these brake pads are OK - still got their wear indicator. It also doesn't look like they have worn unevenly, they have about the same thickness.

Oh well, I've got the new ones already anyway. And clearly the brakes did need some cleaning up as the front wheel wasn't spinning freely, plus the pistons aren't moving too freely. They aren't seized but they could definitely be better.
« Last Edit: April 21, 2018, 06:04:56 PM by Kookas »

Offline Kookas

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Re: Front brakes - left pad worn much more than right pad - rebuild?
« Reply #18 on: April 22, 2018, 03:10:42 PM »
So, unfortunately, those seals posted earlier were indeed not correct. It seems the dust seals' diameter is about 1mm too big (same difference between OD and ID though), and the oil seal is just way bigger than what I had.

I've opted to keep using the old oil seals but fit the new dust seals, but it's looking like a caliper swap is in this bike's long-term future, if and when the old oil seals die.
« Last Edit: April 22, 2018, 03:16:21 PM by Kookas »

Offline alpo

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Re: Front brakes - left pad worn much more than right pad - rebuild?
« Reply #19 on: April 22, 2018, 08:13:16 PM »
That's a bummer. It really irks me when they tell you something that is not correct.

Since the old seals were not leaking you should be fine cleaning them up and reusing them. Lube them with a little clean brake fluid when installing them, so they slide smoothly in the bores.