• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

Cleaning up caliper bores

  • Thread starter Thread starter seano
  • Start date Start date
S

seano

Guest
I've got lots of hardened old brake fluid in the grooves of my caliper bores. Been scraping it out w/ a jeweler's screwdriver and magnifying glass - it's getting old real quick . . . Anything I can soak these in to soften up the crud?
 
grab a dremel and a brass wire brush on the end, will get it clean quick

41PaRMiBu0L._SL500_AA300_.jpg
 
yes do wear eye protection....

I did not want to use the steel bristle ones as I was afraid of damaging the calipers, by gouging a groove or something
 
NO WIRE BRUSHES ON ALUMINUM!!!!!! They can leave uneven bore width from them basically grinding the bore up. If your planning on repainting them or the finish is waxed, I suggest you throw it in a can of laquer thinner for a few hrs and that will soften the gunk up. Also you never want to wire wheel things like heads and engine case and covers to get the old gaskets off. This leaves low spots and grooves in them that almost always result in a leaky gasket thats a Biitch to get to seal.
 
Last edited:
chuck hahn said:
NO WIRE BRUSHES ON ALUMINUM!!!!!! They can leave uneven bore width from them basically grinding the bore up.
Click to expand...
If the piston needed to seal to the bore, I might agree with you, Chuck, but a light touch with ANY wheel, and limited to the area where the rubber seal rides in the groove, will remove any stubborn crud without damaging the caliper.

.
 
Thats why I asked about the finish and his intentions about repainting...the laquer thinner will soak it off without any worry of any bore damage at that point. IF , as a last resort, I would use something like a gun cleaning brush and do it by hand. High speed Dremels would scare me off because ( to me ) its just too easy to scrub a dimple in there and then yiour basically screwed. Dollar store near me has what look like tooth brushes but have brass and stainless bristles. Those would be ideal and more controllable.
 
Last edited:
OR...How about an overnight soak in some vinegar or carb dip?? some penetrating oil and a green dish scrubby may also scrub the groove out well. That grey scaley craps a bugger..I am very aware!!!!
 
Steve..By "bore" I was referring to the Bore of the groove the seal slips in. I wouldnt want to get it out of round for fear the seal wouldnt snug up perfectly around the piston..Does that make more sense??
 
Thanks so much for all the input guys. I'll start w/ the vinegar soak and go from there.
 
Vinegar will take a day or 2..overnight in some berrymans should get them real nice inside..regular tooth brush to spiffy them up and they will be good for another 30 years!!!
 
chuck hahn said:
Steve..By "bore" I was referring to the Bore of the groove the seal slips in. I wouldnt want to get it out of round for fear the seal wouldnt snug up perfectly around the piston..Does that make more sense??
Click to expand...
OK, that's fine. Some people are of the impression that the inside of the caliper needs to be spotlessly clean because it needs to seal against the piston. In fact, the piston only touches the rubber seal, so the rest of the cavity really does not matter, as long as it's nothing that will affect proper operation.

I still stay that a light touch with a wire wheel won't hurt the groove (bore) that the seal sits in.

.
 
Well, It kinda DOES matter in the sense that I wouldnt want any of the scale getting in between the seal and piston and causing a leak..or the stuff getting around and contaminating the brake fluid.
 
chuck hahn said:
Well, It kinda DOES matter in the sense that I wouldnt want any of the scale getting in between the seal and piston and causing a leak..or the stuff getting around and contaminating the brake fluid.
Click to expand...
I believe that falls into the "as long as it's nothing that will affect proper operation" category. :p

.
 
I've cleaned and rebuilt about 15 calipers in the last 5 years.Of those 6 had pitted, rusted or cracked/missing chroming on the pistons. Each of those 6 calipers also had concretions on the sides of the bores hard enough to require scraping. On the advice of my pro-wrench I used the dremel brush technique to clean them up.

I think, like plaque in a human artery, if any of that crud breaks off or remains in the bore it stands a good chance of plugging the "in" line or working its way passed the seal or possibly damaging it. The chances might be slim of this happening but I'm not keen on a possible problem so I'd rather clean it up when I find it.

Out of habit now I routinely dissassemble, clean and rebuild the calipers on any new to me bike and I'm doing that this weekend on the 550. I'm convinced that folks generally don't give a moments thought about their brakes unless there is an obvious issue. You can tell right away how well they've been looked afterwith a quick peek at the colour of the fluid. Everyone I've looked at has been brown to black. Call me paranoid, but an ounce of prevention is always better than a pound of cure.

Ride safely friends.
spyug
 
spyug said:
I've cleaned and rebuilt about 15 calipers in the last 5 years.Of those 6 had pitted, rusted or cracked/missing chroming on the pistons. Each of those 6 calipers also had concretions on the sides of the bores hard enough to require scraping. On the advice of my pro-wrench I used the dremel brush technique to clean them up.

I think, like plaque in a human artery, if any of that crud breaks off or remains in the bore it stands a good chance of plugging the "in" line or working its way passed the seal or possibly damaging it. The chances might be slim of this happening but I'm not keen on a possible problem so I'd rather clean it up when I find it.

Out of habit now I routinely dissassemble, clean and rebuild the calipers on any new to me bike and I'm doing that this weekend on the 550. I'm convinced that folks generally don't give a moments thought about their brakes unless there is an obvious issue. You can tell right away how well they've been looked afterwith a quick peek at the colour of the fluid. Everyone I've looked at has been brown to black. Call me paranoid, but an ounce of prevention is always better than a pound of cure.

Ride safely friends.
spyug
Click to expand...

+ 1 gazillion to all of that.

Oh, and the wire wheel won't hurt anything unless you get stupid with it. I find that the steel ones last a lot longer than the brass before coming apart. Furthermore, the only part of the caliper that actually matters to sealing is the OD of the seal groove. Even that can have small pits and still seal. It just can't have a pit large enough to cross the sealing face. The walls (and pits on the OD) only need to be free of burrs that could cut the seal.
 
Thanks again for the wealth of information as I like to only do things once - ok, maybe only twice . . .;)
 
I pulled my front clipers from the 550 yesterday broke them down. The left one was clean but the right one looked like this:
cal1.jpg


Lots of crud built up at the bottom of the bore, almost like a mud. Thankfully soft and easy to remove:

cal2.jpg


The seal was good but there was crud behind it which had pushed it outward slightly and caused it to jamb the piston. The piston was easily removed with a shot of 80psi compressed air through the transfer port ( the little hole in the casting) and it had no pits or cracks in the chrome. For any newbs attempting that procedure, wrap the piston/caliper with a good rag and hold it down firmly on a bench with your hand over the piston. It will come out with some "violence" and if not contained the piston could become a deadly projectile. Keep your face out of the way.

So now having looked at 17 calipers I can add another one with issues and I still need to look at the back one.

I'm putting the calipers back on today in hopes of road testing the bike later or sometime this weekend.

Cheers,
spyug
 
Last edited:
Yeah I'm rather fussy about brakes too. I will never understand how some guys spend so long refining an engine to produce more power and not pay so much attention to the brakes. I've only ever worked on two bikes but on both the first thing I did was maximise the brakes' abilities to stop the bike.
 
You must log in or register to reply here.
Back
Top