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Just passing thru
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Discussion Starter #1
I'm replacing all 4 brake pads on the front of my bike and in the service manual it says to remove the master cylinder cap to allow for the compression of the caliper pistons and rise in brake fluid level.

This seems unnecessary if no fluid was ever added. Cant I leave the cap on or am I missing something?
 

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Yes it pushes the fluid back into the master that was pushed into the caliper when the pads wear.The piston in the caliper compinsates for pad wear by pushing out.hope this helps
 

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I'm your huckleberry
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I would open the bleeder while pushing the pistons back in. Keep pressure on the piston and close the bleeder then top off with new fluid. My reasoning behind this is if ANY contaminants are anywhere in the line or caliper you will force it past the seals in the master cylinder possibly causing problems. After having this problem on early car/truck abs systems I adapted the stategy to all vehicles.
 

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SNAFU organizer
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Only as it relates to the rapid movement of fluid back into the reservoir as any backpressure/resistance from trying to force air thru a finite venthole in the cap will slow the process. Whereas with cap off no possible restriction at all.
 

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I {Heart} Hookers.
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I would open the bleeder while pushing the pistons back in. Keep pressure on the piston and close the bleeder then top off with new fluid.
Ditto on this Ed.

Pushing the fluid backwards through the master can push back dirt and old fluid.

Theoretically, if you're changing pads, you should change the fluid as well.

It's easier to attach a piece of tubing to the bleeder and run it into an empty soda bottle. Crack the bleeder, and push the pistons back. The old fluid will go into the bottle, plus, the open bleeder prevents pressure from trying to push out the other brake pistons.

When finished, pump up your brakes slowly, and when good, refil reservoir to proper level.
 

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STAND AND FIGHT!
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Did you get your slipper clutch installed?
 

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You can do it either way bleeder screw or master cap removal.
I usually change the fluid when I do pads on a sled. fliud is cheap and bleeding them is not so hard.a little step to take but itll save your life and you know your fluid is fresh and non contaminated.
 

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Just passing thru
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Discussion Starter #9
Thanks folks, Good advice. One more question, I have the calipers off of the forks for a front wheel replacement and originally thought it would be easier to do the brakes while off of the bike. Do you think this is true or is it easier to do when the caliper is in place using the old putty knife trick?
 

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Just passing thru
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Discussion Starter #10
Did you get your slipper clutch installed?
Not yet Nathan. The job calls for draining the oil and with less than a thousand miles on the oil I'm going to wait until oil change time for that job. I'll keep you guys posted on that.
 

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I {Heart} Hookers.
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Thanks folks, Good advice. One more question, I have the calipers off of the forks for a front wheel replacement and originally thought it would be easier to do the brakes while off of the bike. Do you think this is true or is it easier to do when the caliper is in place using the old putty knife trick?
Having them off is easier. Place a flat-bladed screwdriver in between the pads on the caliper you're NOT changing, to prevent the pistons from pushing out, when pusjing back the pistons on the caliper that you're changing the pads on. Using the old pads, you can pry against those without fear of damaging anything.

After you install the pads on the first caliper, just put something of the approximate width, (like an old pad off the side you just did) in between the new pads, to prevent them from pushing out when you do the opposite side, and having to pry back on the new brake material.....
 

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STAND AND FIGHT!
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Just my own preferrence, I always use the old pads in place on the rotor to assist me in pushing back the pistons. On dual rotors, I'd expect to have to use a big screwdriver or a tire tool on both rotors at once, wedged between the rotor and the pad at first, I'd prefer to protect the rotor asap with a business card or piece of beer can, but still fully depress all the pistons at once using the worn pads and the rotors as spacers to make the leverage/pry tool most effective.
 

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I {Heart} Hookers.
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I'd prefer to protect the rotor asap with a business card or piece of beer can....
Next time you empty a 1-2 liter bottle of soda, cut a large chunk of the bottle's flat side plastic out and keep in your tool box for that very reason, Nathang. :thumb
 

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I {Heart} Hookers.
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Remind me to never to ride with Brutus. I see all he thinks about is beer. I don't like to ride with a drunk. Maybe he should be on the BEER forum.

Get on the wagon brutus before you kill yourself...
Nobody invited you to ride anyways stay outta my buisness.Maybe you should be on the %&eer forum.
You better start rethinking $hit when you call someone a drunk butthead.:stir:eekers:thumb
 
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