[Bobberboibag]

Hey, so Ive taken my rear wheel off to muck around, including the rear brakes. Ive gone to put them back on and found them shut tight, with the piston fully extended. Brake pedal isnt pressed. Ive also taken the engine cases off if thats relevant. If anyone can help Id be real appreciative.

 

[atomsplitter]

Not a big problem. Take a flat blade screwdriver and insert it between the pads. Then work the pads back open with the driver. The fluid behind the piston will return to the reservoir. You likely bumped the brake pedal taking off a cover and with no caliper between them they closed. Not a panic situation.(yet).

 

[Bobberboibag]

Not a big problem. Take a flat blade screwdriver and insert it between the pads. Then work the pads back open with the driver. The fluid behind the piston will return to the reservoir. You likely bumped the brake pedal taking off a cover and with no caliper between them they closed. Not a panic situation.(yet).

Sweet, that's what I did, thanks man. That makes total sense

 

[Northern bobber]

I don’t use a screw driver for fear of chipping some material from the pad. I get a wooden clothes peg ( the tapered end ones). I insert the tapered end then just work them open them as describe above

 

[atomsplitter]

I don’t use a screw driver for fear of chipping some material from the pad. I get a wooden clothes peg ( the tapered end ones). I insert the tapered end then just work them open them as describe above

I use what I have available, I don't keep any clothes pins in my tool box. I suppose I could whittle a stick tho.......

I also notice the pads clamp onto a steel rotor under a lot of inertial load and don't chip, hmmnn......

I will admit yours in the safest methodology and would agree it's best to err on the side of caution.

 

[Traveller]

Did anyone mention to loosen the bleeder screw a ¼ turn to release fluid / pressure?
If not the pads are going to be hard to separate.

 

[Stumac]

Did anyone mention to loosen the bleeder screw a ¼ turn to release fluid / pressure?
If not the pads are going to be hard to separate.

Is that something you actually do or just a suggestion that's definitely going to complicate things for the OP. A small amount of effort will be required to push the pistons back, particularly to start with when you are only levering on the edge of the pad / piston. Once you have opened up a larger gap and you can get right in to push on the piston / pad squarely it will be easier. Releasing fluid is not necessary and could lead to further complications! Alternatively drop the pads out and use the proper tool ($8.49 from Harborfreight)

 

[atomsplitter]

Traveler, if the piston was siezed you make a point, however this isn't an antique caliper with mung fluid, it's off a new bike and the last thing you want to do is lose fluid from the system. The pads look fresh in the photo so the only thing necesssary was to push the piston back in to seperate the pads for reinstallation. He was able to so that based on his second post quite easily. The amount of fluid in the system is dictated by the pad's depth. As the pads wear the level in the reservoir drops. When it looks like you need to add fluid (barring a leak) you really need to change brake pads. You should flush the system and change fluid when the brake fluid is turning brown. System flush is best done when you change to new pads.

 

[Traveller]

@atomsplitter When I have to change my pads I will keep this in mind.

I will say that this is the first bike I've owned that was made in this century and I haven't needed to change the pads yet. But in the past I have always cracked the bleeder a bit to relieve some pressure when spreading the pistons. I don't crack it enough to let fluid pour out, just enough to let it drip.

Another tip, when you pull the calipers off for any reason, put a small block of wood between the pads and tape it in place with painters tape to keep from accidentally closing the pistons.

 

[Spud]

I have a load of nylon packers I used in construction they came in 2, 3, 5, 10mm so as soon as I slipped the caliper off the disc I would shove a few of these in to prevent this happening.

 

[atomsplitter]

I have a load of nylon packers I used in construction they came in 2, 3, 5, 10mm so as soon as I slipped the caliper off the disc I would shove a few of these in to prevent this happening.

That's a great use of material on hand. You can use about anything to keep the pads seperated, but if one fails to think about it and the pads somehow squeeze shut, just push them open again.

I have restored enough old bikes (too many to count) that brakes are always an issue. I did a barn find Suzuki GT550 back in the day and it had been in the barn for 15 years. That was a looong term project, but everything was working when I got done (including the motor). The brakes were drum front and rear, that's how far back I go with brakes. Here's a pic of that bike after a test ride.

 

[Spud]

Sometimes the caliper pistons can pop out and are a pain to get back, apparently, that's why I do it, preventative maintenance 👍

 

[Wooden rat]

Splitter, a friend in high school hat same zuki. It's a 2 stroke if I remember correctly. It would out run a phone call

 

[atomsplitter]

Splitter, a friend in high school hat same zuki. It's a 2 stroke if I remember correctly. It would out run a phone call

Correct, it was a wing-a-ding. I offered to fix the bike if the guy paid for the parts. After an initial estimate of parts he gave me the title with a "good luck." He did get to ride it one last time before I sold it on fleecebay. I'm pretty sure I covered that particular repair escapade in my first book (sadly now out of print).