Front brake calipers - rebuild?

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bingo808
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Front brake calipers - rebuild?

Post by bingo808 »

Hi
While I'm waiting on a set of drill bits to arrive to attack the fuel cap, I though I'd remove the front wheel to get a new front tyre for registration.

All went well, I used ratchet straps to lift the front wheel, thereby allowing me to remove the front axle.

BUT left front caliper is oily, as are pads. Rebuild or go 2nd hand calipers? I say rebuild both left and right, as bike has high kms.

Friend pointed out that pistons/bore could be pitted. So maybe I should disassemble caliper first to check condition?
Someone put it together, so I should be able to pull it apart.
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MacV2
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Re: Front brake calipers - rebuild?

Post by MacV2 »

Full strip down. Clean the pistons & inspect if the corrosion isn't too deep you can dress them with a whetstone...

Oily ??? Its not the fork seal leaking is it ? That will be the only place oil can be comeing from at the front.
Making up since 2007, sometimes it's true...Honest...
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bingo808
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Re: Front brake calipers - rebuild?

Post by bingo808 »

MacV2 wrote: Fri Jul 16, 2021 6:18 am Full strip down. Clean the pistons & inspect if the corrosion isn't too deep you can dress them with a whetstone...

Oily ??? Its not the fork seal leaking is it ? That will be the only place oil can be comeing from at the front.
Correction. On 2nd glance it does not smell like brake fluid. I think it may be the fork seals. Best to replace both sideS?
Someone put it together, so I should be able to pull it apart.
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MacV2
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Re: Front brake calipers - rebuild?

Post by MacV2 »

bingo808 wrote: Fri Jul 16, 2021 7:04 am
MacV2 wrote: Fri Jul 16, 2021 6:18 am Full strip down. Clean the pistons & inspect if the corrosion isn't too deep you can dress them with a whetstone...

Oily ??? Its not the fork seal leaking is it ? That will be the only place oil can be comeing from at the front.
Correction. On 2nd glance it does not smell like brake fluid. I think it may be the fork seals. Best to replace both sideS?
Yep, no point in only doing one side... Chances are the other side will go a few weeks after you've done the bad one... Sod's law... Fresh oil wont hurt either, it's possible it's still the origional oil from the factory... Get new seals & dust seals & don't be tempted to buy cheap ones... Or you'll be doing it again after a few miles. Also worth looking at getting new bushes top & bottom.

Bottom bush... You'll need 2 of.
https://www.davidsilverspares.co.uk/par ... 415KCR003/

Top bush... You'll need 2 of.
https://www.davidsilverspares.co.uk/par ... 414KCR003/

Read this... viewtopic.php?f=31&t=29710
Making up since 2007, sometimes it's true...Honest...
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bingo808
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Re: Front brake calipers - rebuild?

Post by bingo808 »

MacV2 wrote: Fri Jul 16, 2021 8:30 am
bingo808 wrote: Fri Jul 16, 2021 7:04 am
MacV2 wrote: Fri Jul 16, 2021 6:18 am Full strip down. Clean the pistons & inspect if the corrosion isn't too deep you can dress them with a whetstone...

Oily ??? Its not the fork seal leaking is it ? That will be the only place oil can be comeing from at the front.
Correction. On 2nd glance it does not smell like brake fluid. I think it may be the fork seals. Best to replace both sideS?
Yep, no point in only doing one side... Chances are the other side will go a few weeks after you've done the bad one... Sod's law... Fresh oil wont hurt either, it's possible it's still the origional oil from the factory... Get new seals & dust seals & don't be tempted to buy cheap ones... Or you'll be doing it again after a few miles. Also worth looking at getting new bushes top & bottom.

Bottom bush... You'll need 2 of.
https://www.davidsilverspares.co.uk/par ... 415KCR003/

Top bush... You'll need 2 of.
https://www.davidsilverspares.co.uk/par ... 414KCR003/

Read this... viewtopic.php?f=31&t=29710
Thanks for the guide link. After going through it, and talking to a mechanic mate of mine, I think I'll just remove the forks from the bike and take them to a shop for them to rebuild. I could do it myself, and it would be a great learning exercise, but I just don't have all the tools.

To remove the forks, just undo the handlebar pinch bolts and the triple clamp pinch bolts? Then slide fork out?
Someone put it together, so I should be able to pull it apart.
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MacV2
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Re: Front brake calipers - rebuild?

Post by MacV2 »

''To remove the forks, just undo the handlebar pinch bolts and the triple clamp pinch bolts? Then slide fork out?''

Obviously first thign is to surport the bike ! Do you have an ABBA stand ? Padock Stands ? Raffter's in the garage ?

First thing is remove the fairing & Mudgaurd then... Take a pic of the cable routing before you remove anything !

Crack all the nuts that need to be removed before lifting the bike...

But yeah once you have got the front end off the floor & the bike safely surported... It's gonna be like that unable to move for some days...

Your doing the calipers so drain them off first & remove them. Front wheel out, note the wheel spacers & which side they go on... Take the bars off, remember the wire clip thing top of the bar/fork & doing one fork at a time... Loosen the top pinch bolt. Then holding the fork with one hand loosen off the bottom yoke bolt... & the fork will slide out.
Last edited by MacV2 on Fri Jul 16, 2021 2:57 pm, edited 1 time in total.
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tony.mon
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Re: Front brake calipers - rebuild?

Post by tony.mon »

You forgot mudguard off.
It's not falling off, it's an upgrade opportunity.
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MacV2
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Re: Front brake calipers - rebuild?

Post by MacV2 »

tony.mon wrote: Fri Jul 16, 2021 2:18 pm You forgot mudguard off.
Happy now...?
Making up since 2007, sometimes it's true...Honest...
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bingo808
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Re: Front brake calipers - rebuild?

Post by bingo808 »

Actually, a mate of mine told me to give a small piece of plastic a go first - it's called "Sealmate"

It gets under the lip of the seal and removes any dirt etc. I think it's worth trying first.

I still need to clean up the caliper etc and get a new front tyre but can do that after.

Someone put it together, so I should be able to pull it apart.
tony.mon
Posts: 15943
Joined: Wed Jul 25, 2007 10:46 pm
Location: Norf Kent

Re: Front brake calipers - rebuild?

Post by tony.mon »

MacV2 wrote: Fri Jul 16, 2021 2:57 pm
tony.mon wrote: Fri Jul 16, 2021 2:18 pm You forgot mudguard off.
Happy now...?
Lovely, thanks for sorting that out.
It's not falling off, it's an upgrade opportunity.
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MacV2
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Re: Front brake calipers - rebuild?

Post by MacV2 »

bingo808 wrote: Fri Jul 16, 2021 10:21 pm Actually, a mate of mine told me to give a small piece of plastic a go first - it's called "Sealmate"

It gets under the lip of the seal and removes any dirt etc. I think it's worth trying first.

I still need to clean up the caliper etc and get a new front tyre but can do that after.

Depends on how bad the leak is... It might stop it for a while or compleatly... You have to ask how much oil has leaked out tho...?
Making up since 2007, sometimes it's true...Honest...
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