Disc Brakes

Disclaimer: the last time I owned a dirt bike, drum brakes were the norm. Since I don't want to do the Hot Tub Time Machine thing and go back to the 70's, I must live in the present.

I like disc brakes, but I'm stumped on what I need to do. I watched the RMATVMC video on them, and I get the idea. I'm replacing worn out pads with new, thick ones.

But, the part about "spreading the pads so the rotor will fit back in" - mine won't budge. I presume this is because the pressure on the calipers is why. So I "think" I've got to bleed the pressure to do this.

Is this right? I can't seem to find the answer. Oh, and many kudos to those of you who address these things. Who knew Pine Sol was the way to clean a carb? Happy to report that, plus a new pilot jet, solved my "won't run without the choke on" problem on my 450.

Stick a big screwdriver in between the old pads and twist hard.  The pistons should move and be able to retract all the way.   If they really won't budge, pump the brake with the caliper off and connected.  Pump until one of the pistons pops out.  If one isn't moving at all, hold the other one in a vise and try to pump to unstick the stuck side.  You've got to get the pistons out, clean them and the bore and replace the seals.  If one is hopelessly stuck then you'll have to replace the caliper.  Been there, done that.  Once you've done all that, read some posts or watch youtube videos about bleeding brakes.  

You don't want to go back to drum brakes.  Nor should you be listening to the Bee Gees or wearing bell bottoms.  Disk brakes are mechanically simpler and more effective.  

They should slip back in fairly easily. I hate to pry them to hard as you can damage the pads doing that. Sometimes you can use a couple small c-clamp to push them back in...be careful if using that method though as a c-clamp has quite a bit of force and over doing it can damage the caliper.


I had one puck get "stuck" years back because it sort of somehow rolled or pinched a little sliver of one of the caliper seals in between the puck and the caliper bore for that puck.


 Had to really pull on the lever hard to get any brakes, and then they did not want to release very well either. Also was a real PIA to get that puck out to replace the seals. 


 I finally got it out by using a small piece of wood to hold the other non-stuck puck in place while pushing compressed air into the brake line inlet to blow the stuck one out.


 I am currently going through that bike's front brakes  AGAIN as the brakes have faded .....again....and I want em back!

Take the lid off of the top of the master cylinder so fluid can flow back into the reservoir

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