how often should front brake be rebuilt?

I have an 08 track bike that I have owned for 2 years so I have no clue if or when the front brakes have been rebuilt. I pulled the calipers and removed the pads and sprayed them with brake clean and scrubbed them with a tooth brush. I noticed all four pistons where not operating at the same rate, although it was better after the cleaning. All four pistons seem to be free of any kind of corrosion or damage. My question is should i tear them down and replace the seals to fix this issue and is it retard proof because that last thing i want is brake failure on the track.

 

When I am cleaning my calipers and one piston isn't moving smoothly I will tear them down. However, I won't necessarily replace the seals unless they are torn or look worn.

There are plenty of videos on how to pop out a piston, clean it and put it back in. Pretty idiot proof and nearly impossible to destroy a caliper in any permanent way. At worst you may tear a seal as you learn.

An air compressor, some small blocks of wood and zip ties is all you need to pop out the pistons and check them for crud.

I suggest you go for it. It is a relatively simple skill that is worth knowing.

 

In the future, pro mechanics that know more than me, said to just clean with soap/water and toothbrush. Brake clean can cause the seals to expand. I don't believe our pistons all came out at the same rate when viewing off the bike.

 

The pistons will not operate equally without the pads contacting the disc. Don't rely on what you see the pistons doing with the calipers "unloaded". And rebuilding calipers isn't "retard proof". You can trash a piston/seal/block if you aren't careful.

 

3 race weekends/4 track day weekends I'll pull them apart. Simple green the Pistons and clean them with a nylon brush. Somewhere in the middle I use 2k grit sandpaper and while the piston is wet with simple green I give them a good once over. Clean them up nicely, put in new seals and re-bleed with SRF or Motul.

I ALWAYS feel a difference in feel after. More feedback at the lever. Obviously the more caked up those pistons are the bigger difference you'll notice.

I also check my valve clearances every other weekend and the oil gets changed no matter what every weekend. So I might be going over board but it helps me not focus on anything other than riding when I'm riding.

YRMV.

 

Post I did about it a while back if you need any guidance (obviously it was for an older GSXR with 2 piece calipers that needed to be split but I used the same basic process when I tore apart R6 and new GSXR Brembo mono blocks). I usually do it once a year depending on mileage.


http://forums2.13x.com/index.php?threads/cleaning-calipers.284701/#post-3490099

 

Thanks for all the help guys it's greatly appreciated! Now is there anything I can lube the Pistons with once I'm all done scrubbing them? I read that some people use red grease does this sound correct

 

Very Very light coat of grease. Red. Green. Blue. Whatever. Just remember as those Pistons come out of the caliper and whatever grease is on the piston is going to attract brake dust. But if you clean your Pistons regularly it's no problem

 

Popping out pistons and cleaning them is simple enough. Just be methodical and orderly. I'm going to suggest you
Avoid grease on the Pistons for the vary reason stated. It will collect tons of dust. A dry Teflon spray is ideal. Eliminates the build up.

 

I never grease the pistons. Just some new brake fluid on everything as it's going back together.

 

I've never used anything other than fresh brake fluid (which is what the service manual recommends, in fact I think it says NEVER use anything but fresh brake fluid to lubricate when reassembling). I don't want to take any chances with the fluid in the system mixing with any other crap there. Brake fluid can be temperamental stuff.

 

Don't grease the Pistons with anything but brake fluid. There is a brake fluid specific grease called red rubber grease that doesn't break down from the brake fluid but I don't think you can buy it in America.

 

http://www.ebay.com/itm/18g-HQ-Red-...503247?hash=item3f199a9ecf:g:EBwAAOxy6MBSTrpz

 

This reminds me of the "whats the best oil" kind of thread.

 

Got this exact stuff and used it when i rebuilt my 2 piece calipers. Worked great and was cheap no issues with the brakes what so ever now

 

That's the stuff.

 

Thanks again! seems like all the bases are covered and I won't have anything to worry about

 

Once a year complete disassembly and cleaning with brake fluid, clean everything I can get to without disassembly every time I replace pads

 

One of these days, after tearing down and cleaning a brake system, I'm gonna fully reassemble it submerged in a vat of brake fluid.

 

While everyone here seems to recommend brake fluid for rebuilding here is a related post. Someone did some "impromptu" testing. As a disclaimer I own two Guzzi's, but I had nothing to do with the "test".

http://www.v11lemans.com/forums/index.php?showtopic=19330 Only linked for informative purposes.

FYI I use brake fluid to rebuild and mild soap to clean; Palmolive, "tough on grease, soft on hands".