Yamaha Thundercat Brakes...

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Yamaha Thundercat Brakes...

Hi Guys

 Just bought myself a Thundercat that needs a little cosmetic TLC and the front brakes sorting...

Took the front brakes off and struggled to free the pistons off completely... they are still partially seized but until I can source replacements they will have to do for now - they are much better than they were...

But I am having MAJOR problems bleeding the calipers... the MC doesnt seem to sucking air down into the calipers... can anyone tell me the best way the bleed these calipers?

I have tried the conventional squeeze lever, tighten nipple, release, etc... also tried sucking the fluid through the bleed nipple via a pipe...

Will something like easi bleed kit sort it perhaps?

Itching to ride the bike as only had it a few hours so want to get this sort ASAP...

Any help appreciated  

To be honest i wouldnt want to ride it till the brakes are 100%, I would strip the calipers and give them a good clean with wire wool, and maybe some new seals if needed. If they're still siezed thats probably why they aint bleeding properley in all honesty.

They arent bleeding at all though...cannot get any fluid into them what so ever!

I replaced the seals on my brakes and got to the point where I couldn't get any pressure at the lever - this usually happens when you have an airlock. Take the caliper off, make sure the bleed nipple is uppermost and you should be able to clear it.The other point where an air bubble can often sit is in the banjo next to the master cylinder...

Loosened the MC banjo off and pumped a few times to clear any air locks and re-tightened... I guess removing the caliper is next then... you mean turn the caliper so the nippled is facing up?

Yep!PS Tapping the brake lines can also help dislodge an air bubble.

If it's a a lot of air trapped in there, then one of the pressurised Ezi-bleed kits will sort it no problems - just be careful to not use too much pressure.On the other hand, if the calipers are a bit crudded, the master cylinder may be duff too - if the piston seals in the master cylinder are worn then you'll never get the thing to bleed..Slightly puzzled about the calipers too. What does "partially siezed" mean? They're other stuck fast, or they're not. If not, get the pistons out a little way, and clean them with a soft brass spark plug brush (softer than the steel so won't damage it). If a job's worth doing, it's worth doing properly.

There was a LOT of air in the system.... took the best part of an hour to remove most of it and its still not spot on - going to leave it a couple of hours and do a final bleed....The pistons are moving but seem very sticky... saying that they dont seem to be binding the disks so they are fine for now...But next week got some braided lines coming so I will clean the pistons up when I fit the new lines....MC is fine ... Cheers for help guys

Hi         Bleed my thundercat brakes at weekend, as fluid looking old ! solid lever, but calipers wont release from disks ? worked fine before, pistons go back easily ? anyn ideas ?  cheers

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