After more than a year of CRF ownership I thought I'd have a look at the front brake caliper to see why it's always been a struggle to get the front wheel off. Turns out that the pistons are seized solid and the pad retaining pin won't come out either. Moan wail tearing of hair etc. etc.
What do I do? Is it a feature of dirty bikes? Is it worth getting John T to try to salvage it or do I get a scrapper off ebay and hope for the best.
I've still got a micron of pad left so am not planning to hang up my thermals just yet.
You make a valid point Pedro. It does still work but I can't get the pistons back in far enough to fit new pads or get the wheel on/off without cursing all mechanical objects ever made. And the retaining pin won't shift. WD soaking to commence this evening.
I would get hold of a caliper kit asap, new seals gaitors etc. Chances are the pin is partially seized into the caliper mounting.
Unbolt the caliper complete from the front, peel back or destroy the retainer pin gaitor and soak the pin where it goes into the mount with WD, if you try and undo it before releasing, it will shear off. A heat gun is useful, apply lots of heat to the mount around pin area, keep working it with pump pliers until it shows signs of movement, heat and soak the threaded part and only then undo it. Once its out you can work the other end of the caliper slider and free that up.
You can do this without disconnecting but be aware brake fluid can flare and catch fire and brake hose when burnt is very toxic. Best disconnect and then reconnect and start to work the pistons back and forth until it appears free. If you have a kit pump the pistons right out to fit new seals.
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Walk a mile in another man's shoes. ...and you will be a mile away... and have his shoes..
You make a valid point Pedro. It does still work but I can't get the pistons back in far enough to fit new pads or get the wheel on/off without cursing all mechanical objects ever made. And the retaining pin won't shift. WD soaking to commence this evening.
If the pistons are moving them it maybe the master cylinder is filling up to the brim when you try and push the pistons back, take the top of the cylinder and then try. Put some rag to collect the excess fluid
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Walk a mile in another man's shoes. ...and you will be a mile away... and have his shoes..
Aye with Paul on that, take brake fluid reservoir cover off and lever the bejesus out of the pistons to push em back in. There may be a more technical approach than using the bejesus methodology.....but them CRF's are an agricultural bit of kit so reckon it will be awright .... Using something like wood to protect piston face when you srart jemmying it with the first big screwdriver that comes tae hand..... Bon chance
On reflection, unless you have spare brake fluid, just loosen the reservoir cap and keep an eye for any fluid being released as you lever the piston back in. Otherwise you may end up with new pads fitted but no brake fluid. I suspect a calliper kit is also a good plan you never know what maintenance regimes former owners may have imposed ....... Or not.
Like Paul says, new seals/pins and boots and you may be lucky with the pistons, and chuck in a set of new pads. Get the bits, or OK me to get them and I'll pick up the caliper and sort it for you. I'm so nice !
Thanks for the advice peeps. I can confirm only a trickle of brake fluid in the reservoir. This was my first hope. With the lid off and a big screw driver stuffed between the pads, prising results it the sound of a tadpole farting as a dribble of extra fluid appears. Also, applying heat has sod all effect yesterday. I've WDed the pin up and will redo it a few time over the coming days before having another go.
Thanks for the offer to fix it LD. Could be my best ever Xmas prezzy, but I'm not giving in just yet.
I dunno....some people and their "maintenance schedules"
I guess having SuperC as a riding buddy means you've adopted his strategy of doing sod-all to the bike between decades.
Every time I had the front wheel out, whether for tyres, pads or fork mods, I had the caliper off and sorted the pistons. They do get sticky, so regular work on those pays dividends. When fitting new pads, I took the reservoir cap off and dabbed some tissue in there to get excess fluid out. Then, using the old pads as protection, levered a large flat blade screwdriver in between them to move the pistons back in. Ideally you would already have cleaned up th bits that are still visible as they won't go back in if there's crud on the rim. I used brake cleaner and a scalpel to get the bits of gunk off - wire brushes tend to damage the soft metal of the piston. I never had a problem with the pin holding it all in and always put copper grease on that so it's a mystery how it has become seized, although being untouched for over a year whilst being doused in water, mud and anything else you've ridden through wouldn't have helped
I'm surprised the pads have lasted as long as a year, as they do get a hard time.
Hope you get it sorted mate - feel free to give me a bell if you want any advice.
Ming. I'm trying to read between the lines here my dirty buddy. Are you saying Tim has been a neglectful wastrel and wanton abuser of the good work you put in on the Ladyboy CRF? . Should we get OFSted to assess his capabilities?
Who stripped the thread on the reservoir cap and said that it wasn't a problem cuz you didn't need to ever take it off anyway and then went off and bought a TE250 with a big wad of muggin's's's's hard earned wonga?
I too have the very same issue but seeing as I is a proper man (from Wales) I just use the back brake.
I bought my wife a vibrator for christmas. since then she's done nothing but moan.
Merry christmas to all you jokers and here's hoping you all get yer christmas noshing, like wot I is gonna get in a couple of hours,
in fact by the time you read this I'll be banging out the Zedds and grinnin like a born again christian WoooooooHoooooooo.xx
. Should we get OFSted to assess his capabilities?
