I really really hate the rear brake

[dirtydog]

I have had nothing but trouble with the rear brake on the other halfs Raptor

Failed it's last MOT on a cracked rear disc, so that got replaced and I swapped the caliper and m/c for one off a mille and all was fine. Well when I say fine it worked enough to pass the MOT.

Then MOT time comes around this year and guess what it fails on the rear brake disc (slightly corroded as not used over winter due to the o/h being preggers) and fails on brake efficiency test.

So I buy a new disc and pads and set about changing them, also decide to put in a freshly cleaned up rear caliper as the mille one was a bit sticky.

And now I have spent the best part of the morning trying to bleed it all. Can bleed it upto the banjo on the caliper but the caliper itself is just not filling up (can't think of a better way of putting it) with fluid. Have got the caliper up above the swingarm so the bleed nipple is at the top but still getting nowhere fast with it.


I am sreiously pi$$ed off with it now have to walk away a couple of times now because I was losing my rag with it

Would using a mityvac thing be more useful for this?

[Brendan1983]

The trouble with the Rear on the Raptor is it has some vacum system on it, I realised this after I managed to empty the whole thing of fluid.

Every time you pump the rear lever you need to then re-tighten the bleed nipple or it will just suck in a load of air, or get some special one way bleed hose. It takes ages but it'll work eventually.

The other way round it which will use loads of fluid is get a cup, full of fluid - make sure your caliper is very clean first and submerge the bleed nipple in it so each time it sucks in in fludi instead of air.

[dirtydog]

I did close the nipple off each time before releasing the pedal but it still wasn't working.

Have got a mate dropping a Mityvac around tomorrow morning so should get it sorted pretty quickly then

[kev]

push the pistons in as far as you can this way you have a smaller void inside the calliper the way i blead it i use an oil can the squirt type connected to the blead nipple and just force the whole can thru works every time on any bike when you ponce about the traditional way it can take forever your moving such a small amount of fluid each pump

[Evil Twin]

Had similar problem. Turned out to be the m/c push rod over adjusted to get the lever up. This meant on return it would not open the reservoir to m/c and effectively you have a fully sealed system. You can test this by releasing the rear brake lever linkage and actuating the pushrod directly.

HTH

[Wintermute]

I agree, hate the back brake, got mine working with a syringe, pushed new fluid thru from the nipple up the system, now works but still crap..
My solution to the problem is just don't use the fekking thing.

[dirtydog]

I agree, hate the back brake, got mine working with a syringe, pushed new fluid thru from the nipple up the system, now works but still crap..
My solution to the problem is just don't use the fekking thing.

I used a Mityvac and sucked it through so got it working well enough for it to pass the MOT.
Unfortunately not using it doesn't work either as it just ends up with the disc rusting and/or the caliper seizing.

Have got 2 rear calipers both have a sticky piston, have got 2 m/c 1 is completely fubarred the other is semi-fubarred

thinking I might take the new disc off and put the old one back on to save the new one for MOT day just like I do with the standard cans