cabby Posted October 6, 2010 Report Share Posted October 6, 2010 Seems my caliper pots are sticking and now at the stage where they won't move at all now, like nothing when the brake is pumped, solution to this anyone ??? Quote Link to comment Share on other sites More sharing options...
hrcmonty Posted October 6, 2010 Report Share Posted October 6, 2010 Seems my caliper pots are sticking and now at the stage where they won't move at all now, like nothing when the brake is pumped, solution to this anyone ??? Give us a bit more info. Front Caliper = 4 pot? All pots stuck or just 1? What have you done to get them stuck? I.E been pushing them back in? If only 1 pot is cocked and the other 3 loose, when you pull the lever, all effort will go to the 3 loose pots? Get some wd40 sprayed on the pots so the WD40 goes down between the pots and caliper. Quote Link to comment Share on other sites More sharing options...
chewy Posted October 6, 2010 Report Share Posted October 6, 2010 It may not be relevant but I had a similar problem whilst on holiday I had front brake sticking on (on a 10 monthold bike Evo) As we were living out of our camper van not too many tools etc available we ended doing all the usual stuff ; pads out wang the lever , jam ou the cyliders that looked to be sticking, wd 40 , etc etc in the end I reluctantly pulled the piston from the master cylinder , no apparant problems but it was sticking on return, greased it etc, still same problem, eventually I removed the O ring seal from master cylinder piston cleaned underneath it carefully with a tissue , turned it around reasembled and bobs your uncle it worked fine. Bizarre as there appeared to be no dirt under it. After loads of messing about this took about ten minutes to chech and do; ... it may be worth a look at that end too. Quote Link to comment Share on other sites More sharing options...
cabby Posted October 6, 2010 Author Report Share Posted October 6, 2010 4 pots front. Were moving slightly but unevenly, then pushed them back and still moving uneven, gave them a splash of wd and now none of them are moving Quote Link to comment Share on other sites More sharing options...
1oldbanjo Posted October 6, 2010 Report Share Posted October 6, 2010 4 pots front. Were moving slightly but unevenly, then pushed them back and still moving uneven, gave them a splash of wd and now none of them are moving I would avoid spraying or putting any petroleum product on the brakes - it can swell the rubber o-rings. Seals and o-rings should only be lubricated with brake fluid or silicone grease. My suggestion would be to take the front caliper apart, clean everything, lubricate the o-rings with brake fluid, and put it back together. If everything moves after assembly....it should work normal. If problems remain you may have master cylinder trouble - or a problem with blockage in the brake lines. Quote Link to comment Share on other sites More sharing options...
cabby Posted October 6, 2010 Author Report Share Posted October 6, 2010 I would avoid spraying or putting any petroleum product on the brakes - it can swell the rubber o-rings. It has to be said they were moving prior to spraying wd but haven't moved since spraying Quote Link to comment Share on other sites More sharing options...
stork955 Posted October 6, 2010 Report Share Posted October 6, 2010 Gday, I second what one old banjo said. However, you can get proper rubber grease for brake rubber components. Use that instead of brake fluid. If any components have been in contact with any petroleum product you will need to replace them. The pistons must be totally frre of marks and corrosion (otherwise they will leak). Good luck. Cheers, Stork Quote Link to comment Share on other sites More sharing options...
cabby Posted October 6, 2010 Author Report Share Posted October 6, 2010 New pots and seal now ordered, only problem now is getting the old ones out and with the main allan bolt rounded, looks like I'm in trouble Quote Link to comment Share on other sites More sharing options...
houseape1000 Posted October 6, 2010 Report Share Posted October 6, 2010 New pots and seal now ordered, only problem now is getting the old ones out and with the main allan bolt rounded, looks like I'm in trouble Im sure I read on here a while back about someone using an expanding bolt to pull out the pistons from the caliper. Quote Link to comment Share on other sites More sharing options...
hrcmonty Posted October 7, 2010 Report Share Posted October 7, 2010 (edited) I have found this which is pretty intresting. http://www.advrider.com/forums/showthread.php?t=345397 WD 40 had very little effect. But yes Brake Fluid etc had less effect. you could argue that 1% swell on the pots is enough to restrict them. Depends on the age of the caliper and how worn the service of the o-ring is to allow WD to soak in. Personally i have never had a problem and it's always lubed my pots perfectly. Edited October 7, 2010 by hrc_monty Quote Link to comment Share on other sites More sharing options...
1oldbanjo Posted October 7, 2010 Report Share Posted October 7, 2010 (edited) Im sure I read on here a while back about someone using an expanding bolt to pull out the pistons from the caliper. You can try using compressed air to blow them out - but be careful as they can come out in a hurry. Wrap the caliper in a towel while trying this method. If that doesn't work you can use a grease gun on the bleed screw to put a lot of pressure on the pistons. You will have to disconnect the brake line and install a screw in the caliper to prevent the grease from coming out the brake line hole. You can limit the travel of the piston by inserting spacers until you get all the pistons moving again. Once a piston is out far enough to lose contact with the seal...you will lose the ability to push the other ones out. The article about the chain o-rings was interesting...but chain o-rings are made to be compatible with oil/greases and may be made different than brake o-rings. I know that I once washed brake o-rings in a parts washer and the solvent expanded the brake o-rings dramitically. The only way to know for sure is to let Thedbf put his old o-rings in WD40 when he gets them out and see how the react. Edited October 7, 2010 by 1oldbanjo Quote Link to comment Share on other sites More sharing options...
cabby Posted October 7, 2010 Author Report Share Posted October 7, 2010 . If problems remain you may have master cylinder trouble - or a problem with blockage in the brake lines. Put another caliper on tonight and it seems this one is sticking also, so can only assume it's the master clynder that is the problem, but what may I ask ??? Quote Link to comment Share on other sites More sharing options...
cabby Posted October 7, 2010 Author Report Share Posted October 7, 2010 Had the master cylinder off, dismantled, cleaned and re assembled, now have no pressure to the caliper at all Quote Link to comment Share on other sites More sharing options...
1oldbanjo Posted October 7, 2010 Report Share Posted October 7, 2010 Had the master cylinder off, dismantled, cleaned and re assembled, now have no pressure to the caliper at all Well what method did you use to bleed the system? I have a hand vacuum that works realy well. You put fluid in the master cylinder and then pull a vacuum at the caliper until the fluid come out without any bubbles. Then I start bleeding by using the master cylinder to pump the fluid and I have a small check valve that I install at the caliper to prevent the fluid from coming back into the caliper once it has been pumped out. Quote Link to comment Share on other sites More sharing options...
cabby Posted October 7, 2010 Author Report Share Posted October 7, 2010 The usual pumping of the brake and opening and closing the bleed nipple Quote Link to comment Share on other sites More sharing options...
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