Cleaning caliper pistons.

[dipshit]

Having watched this vid http://www.youtube.com/watch?v=aHtxBI8NEMg a couple of times I thought I would give my caliper pistons a clean today.

My bike is a year and a half old with 13000 ks on the clock and the pistons or pads haven't been touched before.

This was pumping the pistons before I started cleaning them. Two moved quite fast and the other two didn't move much at all...
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(the first caliper I did was actually worse and only one piston moved predominantly more than the other three)

Then after cleaning with a toothbrush and soapy water for a while they did indeed all begin to move at the same rate...
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So probably not a bad idea to include this job in your maintenance schedule from time to time. It can only help in keeping your bike performing as it should.

[imdying]

It's only four bolts and another half hour, every second time you clean the bike should be adequate. Any longer and it becomes a chore to scrape that baked on shite off.

[dipshit]

It's only four bolts and another half hour, every second time you clean the bike should be adequate. Any longer and it becomes a chore to scrape that baked on shite off.

Yikes! I was thinking maybe every 6 months or so.

I bet there is lots of bikes that hardly ever get the pistons cleaned.

Does your typical bike shop mechanic clean the pistons when installing new pads like they should if someone took their bike in for new pads...???

[tri boy]

Does your typical bike shop mechanic clean the pistons when installing new pads like they should if someone took their bike in for new pads...???

If the client is willing to pay the extra 1/2hr labour, of course they will.
But most people are not willing to get preventative maintenance done. Then bitch and moan at repair costs because they cheaped out originaly.
Trades people love to do a full job. It's customers generally who prevent it.

[schrodingers cat]

Yep. When I test rode my new (old) bike I remarked to the guy that the rear brake was pretty 'dead'. He replied that he never used the rear brake.
Got it home and decided to service the rear calliper. It took a good 80PSI to get the pistons out...


BTW - don't be tempted to simply clean the pistons with brakekleen. When it contacts the brake seals it swells them.

[dipshit]

BTW - don't be tempted to simply clean the pistons with brakekleen. When it contacts the brake seals it swells them.

True. I used warm water with a bit of car wash shampoo... then rinsed with fresh water afterwards.

[schrodingers cat]

True. I used warm water with a bit of car wash shampoo... then rinsed with fresh water afterwards.

This man is a maintainance ninja!

[dipshit]

If the client is willing to pay the extra 1/2hr labour, of course they will.
But most people are not willing to get preventative maintenance done. Then bitch and moan at repair costs because they cheaped out originaly.
Trades people love to do a full job. It's customers generally who prevent it.

You should never install new pads without cleaning the pistons first. You will push all the built-up grime back into the seals.

As the old pads wear down the pistons stick out further and further collecting grime. Throwing thick new pads in means the pistons will have to sit much further in again.

I certainly wouldn't trust a bike shop mechanic to do the job properly and clean the pistons first if you just asked for new pads to be installed.

[dipshit]

This man is a maintainance ninja!

Well you don't want to damage the seals like you say... and you don't want to use anything that could pit/corrode the pistons either.

[tri boy]

Theres a big difference between wiping the pistons clean before fitting new pads, and a full clean of the caiper pistons.But, of course you already know that..............don't you?:mellow:

[dipshit]

Theres a big difference between wiping the pistons clean before fitting new pads, and a full clean of the caiper pistons.But, of course you already know that..............don't you?

...??? Either the pistons are clean before you push them back in or not.

I didn't remove the pistons from the calipers to clean them. Just a scrub of what was sticking out.

[tri boy]

Then you didn't do a full job. Get a qualified person to do it.

[Owl]

So probably not a bad idea to include this job in your maintenance schedule from time to time. It can only help in keeping your bike performing as it should.

I did mine a couple of weeks ago and now have a firmer lever. A chore I had to do about every 3-4000km and now getting 10,000km with updated (coated) pistons.

[imdying]

...??? Either the pistons are clean before you push them back in or not.

I didn't remove the pistons from the calipers to clean them. Just a scrub of what was sticking out.You did an adequate job. That sort of preventative maintenance will quite happily carry you through to full service time (which of course depends on use). A full service on the calipers is a full strip, clean, and replacement of all the seals.

If more people did that small extra bit of work when they cleaned their bike, they'd have better lever feel and stopping power.

tri boy is incorrect; calipers do not require a full strip and clean every time they're maintained. Personally I do a full strip every time I fit new pads, but then I don't wear them out in a day like say somebody at the track frequently would. In their case, I wouldn't even recommend doing it at every pad change, and I am qualified to work on them.

[dipshit]

If more people did that small extra bit of work when they cleaned their bike, they'd have better lever feel and stopping power.

Well after a good ride today it does feel like initial bite is stronger and then you don't need to squeeze quite as hard to get into the real good stopping power.

[Corse1]

Yes mine will be done soon. I thought my discs were warped with nearly 0.2mm run out measured on the bike. After last weekends run to Napier and a terrible pulse in the front end together with a partial lockup at slow speed every revolution I decided to check the rotors as the wheels came off for new tyres anyway.

Well i checked the rotors by laying mount side down on a granite machine shop marking table and ran a DTI around the disc.....Huh only 0.06mm run out max??

Pulled on the lever and looked at the pistons with only one of the 8 (both calipers) moving. So it appears all my brake issues could be a less expensive fix than I first thought. Will clean all the buttons and pistons, refit and test.